Theses and dissertations (Applied Sciences)

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Adressing food and nutrition insecurity through the development and implementation of an agricultural and nutrition education programme on legumes for older farmers living in Mariannhill, KwaZulu-Natal, South Africa
(2020) Mkhize, Nkumbulo Xolile; Napier, Carin E.; Oldewage-Theron, Wilna; Duffy, Kevin Jan
Introduction Food and nutrition security can be influenced by various external and internal factors that contribute to a compromised wellbeing status amongst older farmers who are considered as a vulnerable group. This group faces diverse socio-economic and health challenges within an evolving food system. The complexity of this challenge persistently requires multisectoral intervention programmes, as reflected in the nature of this study. Aim and Objectives The aim of the study was to determine the levels of and address the food intake and nutrition insecurity status of elderly farmers. The main objective was to address the challenges that compromised the health of selected previously non-legume producing farmers by encouraging legume production and consumption amongst them. The findings of the study informed the proposal of appropriate strategies to develop an intervention programme intended to educate the identified elderly farmers and to promote their dietary diversification by means of legume production and consumption. Methodology The study employed a cross-sectional design. A baseline study was conducted that aimed at examining variable relationships using a mixed methods approach involving both qualitative and quantitative data collection techniques. A sample of 112 elderly farmers participated in the baseline study, followed by a case-controlled intervention programme that included preand post-intervention surveys. The measuring instruments included socio-demographic as well as health and medical surveys to elicit data such as blood pressure, blood indices for glucose and cholesterol due to dietary intake, household food security, legume knowledge, legume acceptability and agricultural practices. The data informed the findings of both the baseline and the intervention phases of the study. The baseline study involved a sample of 112 elderly farmers, whereas the intervention study involved two case controls (n=103) that comprised an experimental group (EG: n=53) and a control group (CG: n=50). Data were obtained for both groups by analysing blood indices, dietary intake, yields of legume production (EG only) and legume acceptability levels using statistical analyses of variance, significance and trends of pre- and post-intervention surveys over two years. A follow-up survey (FU) was conducted six months after the conclusion of the intervention phase and involved only the EG (n=32), to assess the impact of the intervention programme on their dietary intake and farming practices. The follow-up study thus compared the intervention data of the farmers’ consumption and production patterns with data obtained postintervention. During this latter study, only dietary intake and production levels were measured. All the data were analysed using IBM Statistical Package for Social Sciences (SPSS), Food Finder software, the Mann-Whitney U test, Analysis of Variance (ANOVA) and T-tests for statistical frequencies, variances and correlations. Results In the baseline study, 79.5% of the participants were women. The mean age of the participants was 63.3 ± 8.2 years. A diverse legume consumption was not observed as indicated by a low legume food group diversity score (FGDS) for 0-9 varieties with a mean of 3.5 (SD ± 1.70). Legumes were the least (19.0%) preferred crop planted by the farmers prior to the study. In the intervention study, the majority of participants were also women (73.6% in the EG and 66.0% in the CG). Of the six varieties of legumes under study, red kidney beans was the most preferred (141.60 kg/ha-1 SD ± 162.11). There was a high significance (p=0.001) amongst the six legume varieties produced, which implies that some legumes had a higher yield than others. A comparison between the genders indicated that the women produced 81.70 kg/ha-1 (SD ± 77.95), while the men produced 33.63 kg/ha-1 (SD ± 166.40). The higher yields produced by the women were significant (p=0.011). Legume consumption improved for the EG because the intervention programme resulted in a significantly (p=0.000) increased dietary diversity score (DDS) of legume intake with a mean (±SD) FGDS from 2.4 (SD ± 1.35) to 5.7 (SD ± 2.56) and a mean (±SD) Dietary Diversity Score (DDS) from 8.59 ± 0.74 to 8.23 ± 1.11, while that of the CG was 3.0 (SD ± 1.82). According to the post-intervention survey, the blood results of the EG indicated nutrient improvement at the 5.0% significance level for blood glucose (p=0.038) and cholesterol (p=0.008). The blood glucose levels of the EG were statistically significant (p=0.037) when this group was compared with the CG in both the pre-intervention and post-intervention surveys. Trend analyses were conducted and compared between those men and women who participated throughout the study (i.e. participation from the baseline to the post-intervention surveys). It was found that cholesterol (p=0.033) and Systolic Blood Pressure (SBP) (p=0.013) were statistically significant when the genders were compared across all phases of the study. Data obtained for the EG in the Follow Up (FU) study six months after the intervention study indicated that the production of legumes had declined (71.8%). This was because the legume intake with a mean (±SD) FGDS of 3.0 ± 2.2 indicated a significant (p=0.000) drop from 5.7 (SD ± 2.56) with DDS from 8.23 (± 1.11) to 8.81 (± 0.47) at p=0.005 significance as determined by the FU survey. It was also found that limited marketing of legumes had occurred, which suggests that the sustainability of legume production and consumption post-intervention by the elderly farmers was a challenge. However, 100.0% of the farmers indicated that they intended to continue their production and consumption of legumes, provided that the constant supply of legumes did not cease. Conclusions Evidence was obtained that the intervention project positively impacted the production and consumption of legumes and that the elderly farmers thus diversified their dietary intake for the better during this phase of the study. However, further investigations need to be conducted to explain the decline in consumption and production in the post-intervention period if support for a healthier lifestyle amongst elderly farmers is to be sustained. The technology to produce legumes with high yields to address food insecurity through more appropriate consumption patterns also needs to be explored in greater depth. Because the two streams of knowledge transfer that involved hands-on training of elderly farmers improved legume production and consumption patterns, this study established a sound foundation on which future studies and intervention strategies for food security amongst vulnerable groups may be built.
Analysis of the nutritional status and dietary intake data of a group of elderly at a day and frail care centre in Verulam
(2011) Govender, Theloshni; Oldewage-Theron, Wilna; Napier, Carin E.
Background: South Africa, a richly diverse developing country has been faced by the consequences of transition attributed to urbanisation and acculturation. A Westernised lifestyle has, therefore, resulted in increasing disease patterns that are characterized by a combination of poverty-related diseases together with the emerging chronic diseases. The shift to a Westernised lifestyle has resulted to a shift in the composition of dietary staples leading to dietary factors related to an increase in lifestyle diseases. These include a high fat, low fibre diet, as well as an inadequate intake of fruits and vegetables. However, this in turn has led to higher energy intakes with insufficient and imbalanced micronutrient intake. Research conducted amongst the elderly in South Africa has clearly indicated that the elderly live within a limited financial budget leading to extreme levels of food insecurity and the social burden of being the head of the household, in addition to being the caregiver to grandchildren and sick children. Due to the current living status the elderly encounter reduced food intake in addition to a reduced variety in their diet, therefore, micronutrient deficiencies are common amongst this age group. Therefore, a consumption of energy-dense foods, particularly staple foods, to stretch the food budget which are more affordable and thus allow for an increased consumption is evident. Aim: To determine the socio-demographic profile, health and nutritional status in relation to the dietary intake patterns to reflect malnutrition among free living elderly (60yrs+) in Verulam. Methodology: Fifty nine randomly selected men and 191 women aged 60+ participated on a voluntary basis in this study. A descriptive survey method was used for this cross sectional study. Trained fieldworkers assisted with the administration of all questionnaires and a registered nurse measured blood pressure. Socio-demographic questionnaires were administered to determine the socio-economic characteristics of the elderly within this community. Anthropometric measurements determined the Body Mass Index according to the World Health Organisation and Asian cut-off points to indentify the risk factors. The Health questionnaire identified the health status correlated to the respondent’s profundity of disease and deficiencies associated to dietary patterns. Blood pressure measurements were taken to determine the hypertension prevalence related to the dietary intake. Two 24-Hour Recall questionnaires were completed by the 250 respondents to identify actual vii food intake and measured against the Dietary Recommended Intake (DRIs). A food frequency questionnaire (FFQ) determined the respondent’s food variety score over a period of one week. The socio-demographic questionnaire, health questionnaire, food frequency questionnaire and anthropometric measurements were captured on an Excel® spread sheet by the researcher and analyzed for descriptive statistics using the Statistical Package for the Social Sciences (SPSS) version 17.0 with the assistance of a statistician. The 24-Hour Recall data were captured and analyzed by a nutrition professional using the MRC Food Finder® version 3.0 software, based on the South African Food Composition tables. Results: The majority of the respondent’s role in the family was mothers (70.8%) and lived in an urban area (68.8%). In addition, 73.2 percent (n=183) of the respondents shared the house with one to five people, and lived in a brick house (74.4%, n=186) with more than 3 rooms (74.0%, n=185). The elderly in this sample were pensioners and, therefore, 76.0 percent (n=190) received state grants of which the total household income ranged between R1001-R1500 (35.2%, n=88). Food insecurity is prevalent as reported by 28.4 percent. Primary school was the highest level of education completed by 52.4 percent (n=131) and English is the most spoken language amongst this group (74.0%, n=185). Women had higher BMI values particularly in the overweight (18.32%, n=35) and obese I and II (58.6%, n=112) categories when compared with men. Blood pressure measurements indicated that 60.0 percent (n=150) of the respondents suffered from hypertension. The use of chronic medication was reported by 84.4 percent (n=212). The total range of individual food items consumed by an individual during the seven-day data collection period measured by the (FFQ) was between 4-66 foods. However, the highest consumption was four food items by 23.2 percent (n=58) of the respondents. The summary of the food variety within food groups indicated a high dietary diversity, of which the other vegetable group reported the highest individual mean FVS (±SD) of 10.86 (±5.82), followed by other fruit, cereal, flesh and Vitamin A rich groups with 5.73 (±4.41), 5.03 (±1.85), 4.08 (±2.23) and 2.43 (±1.09) respectively. The nutrient analysis indicated a deficient intake by both men and women of all the nutrients, except for the mean (±SD) total protein in the women 45.10 (±12.55) and carbohydrate 212.83 (±36.97) in the men. The energy contribution indicated 98.3 percent (n=58) men and 85.72 percent (n=158) women consumed <100 percent of the EER for viii energy. However, the findings from the Top 20 food items measured by the 24-Hour Recall indicated that this community’s diet is largely carbohydrate-based, containing primarily starchy staple foods, sufficient intake of animal products, and insufficient intakes of dairy foods, fruit and vegetables, possibly resulting in the micronutrient deficiencies. The energy distribution of the macronutrients from the average of both 24-Hour Recalls indicates that both men and women are in range of 15-30 percent total fat intake, 10-15 percent protein and 55-75 percent carbohydrate. Conclusion: The results of the study reflect that the elderly in this community are faced with poverty, food insecurity as well as social factors thus contributing to a compromised nutritional status. The progression of malnutrition in particular overnutrition is experienced by the majority of the respondents in this study, however, an increased BMI and the prevalence of hypertension is a risk marker for noncommunicable diseases. However, the high prevalence of inadequate food and nutrient intake amongst elderly discloses the need for nutrition interventions and should be aimed at modifying the elderly food choices when purchasing food, healthier food preparation methods, increasing fruit and vegetable portions and improving daily physical activity to attain a better quality of life.
Application of lipid extracted algae in feed and energy production
(2019) Ansari, Faiz Ahmad; Bux, Faizal; Gupta, Sanjay Kumar; Guldhe, Abhishek
Microalgae are well considered to be promising feedstocks for biodiesel production. Microalgae can be grown under different types of cultivation conditions and their biomass has tremendous potential to be used as biofuel feedstock and for other applications such as feed, food, cosmetics, pharmaceutical etc. Despite the many benefits and the significant development in the field of microalgal biodiesel production, there are several challenges including high cultivation cost and developing efficient downstream processing methods. The biomass production cost is high, which significantly hinders the use of microalgae as a feedstock. Most of the available literature is focused on upstream, single strain and single product strategy, where mainly algal lipids are used for biofuel production. Hence, for improving the sustainability of the algal biofuel production processes and related process economics, a multiple applications approach using integrated biorefinery and exploiting microalgae for environmental benefits is required. To explore the microalgal biorefinery concept it is vital to understand the various cultivation conditions and applications of biomass in different sectors. There are various strategies, which have potential to make algal biofuel technologies more economically feasible and environmentally sustainable. Use of alternative culture media, improving the biomass production and the efficiency of downstream processing (drying, cell disruption, lipid extraction etc.) algal biofuel technology economical. Utilizing lipid-extracted algae (LEA) for energy and aqua feed application will maximize overall economic return and will leave minimal residues as by-product. The major focus of this thesis was to utilize LEA as substrate for biomethane production and protein source in aquaculture feed. However, effect of preceding steps such as microalgae cultivation, biomass drying and cell disruption on major metabolites extraction was also studied. Microalgae were cultivated in different medium (domestic wastewater and BG11) and their biomass yields and biochemical composition (lipid, protein and carbohydrate) were compared. Different drying and cell disruption techniques were employed for lipid extraction and their effect on lipid, protein and carbohydrate yields were evaluated. The yield of major metabolites on whole cell and LEA were also compared. Suitable solvent systems were selected for optimum lipid extraction from wet and dry biomass with minimal toxic effect on LEA metabolites so that LEA can be further used for biomethane and aquaculture feed production. The choice of microalgae at large scale depends upon the number of factors such as their adaptability to large-scale cultivation, biomass production, major metabolites content, robustness towards the open system cultivation and contamination. In this study, S. obliquus and C. sorokiniana were cultivated in wastewater and BG11 medium at laboratory scale. Both strains are indigenous to KwaZulu-Natal. C. sorokiniana showed lower biomass and major metabolites (lipid, protein and carbohydrate) production at large scale compared to S. obliquus. Considering better adaptability to open cultivation, high biomass and metabolites yields, S. obliquus strain was selected for the LEA application study. Microalgae species, C. sorokiniana and S. obliquus were cultivated on BG11 and using different ratios of raw domestic wastewater and post-chlorinated wastewater as nutrient media. The cultivation of S. obliquus and C. sorokiniana showed biomass yield of 1.2-3.5 and 0.78-1.8 g L-1 in BG11 medium, respectively. While biomass yield observed in wastewater was 0.59-1.59 g L-1 for S. obliquus and 0.67-1.45 g L-1 for C. sorokiniana. The higher biomass yield in BG11 medium attributed to the higher nutrient contents in this medium compared to wastewater. The lipid contents for S. obliquus and C. sorokiniana were 20 and 16.5% dry cell weight (DCW), respectively when grown using BG11 medium. While increases in lipid contents of 26.25 and 29.4% DCW were found for S. obliquus and C. sorokiniana, respectively when cultivated using wastewater. Similarly, carbohydrate contents for S. obliquus and C. sorokiniana were 18 and 17% DCW, respectively for BG11 medium. Increased in carbohydrate contents of 25% for S. obliquus, 28.4% DCW for C. sorokiniana were observed for wastewater. Microalgae tend to accumulate more lipids and/or carbohydrates under nutrient stress condition. The nitrogen and phosphorus contents in wastewater are lower than BG11 medium, which were responsible for stressed condition for microalgae. With limited nutrients in wastewater compared to BG11 medium, growth of microalgae is also lower which resulted in lower protein content. Protein content for S. obliquus and C. sorokiniana in BG11 medium were 37.83-48.8 and 25-35.3% DCW, respectively. The protein contents for S. obliquus and C. sorokiniana in wastewater medium were 16.4-27.29 and 15.8-27.3% DCW, respectively. The biochemical composition depends upon the nutrient composition of the medium and cultivation conditions. The two selected microalgae have shown potential for nutrient removal while cultivated in wastewater. The removal efficiency by S. obliquus was found to be 76.13% for COD, 98.54% for nitrogen and 97.99% for phosphate. Microalgae C. sorokiniana cultivation in wastewater removed 69.38% COD, 86.93% nitrogen and 68.24% phosphates. Increased lipid accumulation in the cells was also recorded in stressed conditions due to low nutrient availability from wastewater. After harvesting of microalgae from culture media, the water content in thick algal slurry (>85% DCW) lowers the products recovery. To overcome this challenge drying and cell disruption are required to enhance the efficiency of lipid extraction. Where drying and cell disruption increase the viability of biomass for lipid extraction process. Three biomass-drying techniques viz. sun, oven and freeze-drying and four-cell disruption techniques viz. microwave, sonication, osmotic shock and autoclave disruption were studied for their effect on recovery of major metabolites from S. obliquus. Microalgae metabolites recovery from whole cell and LEA were analysed and compared. The results showed that after lipid extraction, LEA still contained comparable protein to whole algae biomass however, the carbohydrate concentration was reduced. Oven drying exhibited the highest recovery of all the major metabolites followed by freeze-drying; sun drying however, showed lower yields. Despite lower metabolites recovery sun-drying technique is preferable at large scale due to its easy application and cost-effective nature. The main drawback of sun drying technique is weather dependence and required longer period to dry. The microwave and autoclave microalgal cell disruption improved the lipid yield but loss of other compounds was observed. In osmotic shock treatment, due to poor cell disruption efficiency low lipid were obtained and comparably lower protein loss was noticed during lipid extraction. Lipid extraction is crucial step for microalgae biodiesel production. Solvent-assisted lipid extraction is widely used technique for lipid recovery from dry or wet algae biomass. In a biorefinery approach, it is vital to choose appropriate solvents for the optimum lipid extraction whilst having minimal effect on the remaining metabolites (protein and carbohydrates) in LEA. LEA could be used for energy generation or aquaculture feed applications. Six commonly used organic solvents/ solvent systems were used for lipid extraction from wet and dry biomass. The results showed that the lipid extraction efficiency depends strongly on types of biomass as well as solvent systems selected. Lipid extraction from wet algal biomass could reduce the processing steps and save energy incurred in drying. However, the water present in wet algal slurry acts as a barrier, which results in lower lipid yield compared to the dry biomass. The results revealed that among all six-selected solvents, chloroform: ethanol (1:1 v/v) was most effective if wet biomass used specifically for lipid purpose only. To explore the biorefinery concept, isopropanol/hexane composition is the most suitable solvent system because it is less toxic and resulted in high protein (20.07% DCW) and carbohydrate (22.87%) yields in LEA. For dry algal biomass, chloroform: methanol (2:1 v/v) is an appropriate solvent system if biomass used especially for lipid (19.25%) extraction. If LEA to be used for energy and/or aquaculture feed application, DCM: methanol was found to be a suitable solvent system, which gave 32.79% protein and 26.92% carbohydrate yield. Comparatively hexane has lower lipid recovery but shown higher protein and carbohydrate yield in LEA. Due to less toxic, easy to scale up and inexpensive, hexane is preferable as a solvent for lipid extraction if LEA is to be further utilized at large scale for energy or feed application. Anaerobic digestion (AD) of organic residues is well-researched technology for biomethane production. Whole microalgae and LEA has promising potential for biomethane production. The anaerobic sludge used as inoculum for microalgal biomass digestion. Biomethane production from whole algae and products extracted algae highly depends on sludge to algae biomass ratio for higher methane production. The extraction of metabolites also changes the biochemical composition of residual biomass, which can affect the biomethane production. It is vital to understand the effect of various product-extracted algae and as well as pre-treated algae on the biochemical methane potential. In order to compare biomethane potential, four types of biomass were selected namely sun dried powder algae (SDPA), mild heat-treated algae (MHTA), LEA (using hexane as lipid extracting solvent) and protein-extracted algae (PEA). The average methane (CH4) production rate was ~ 2.5 times higher for protein and lipid extracted algae than for whole algae SDPA and MHTA whilst the cumulative CH4 production was higher for pre-treated algae. Highest cumulative CH4 production (318.7mL CH4 g-1 VS) was found for MHTA followed by SDPA (307.4mL CH4 g-1 VS). The CH4/CO2 ratios of 1.5 and 0.7 were observed for MHTA and LEA, respectively. Outcome of this objective revealed that pre-treatment process disrupts the microalgae cell walls, exposing intracellular material and increasing the surface area. The product-extracted algae changes the elemental composition, which decreases the cumulative gas yield CH4/CO2 ratio. Presence of high nitrogen in the form of protein produces ammonia (NH3) which inhibits the methane production. Therefore, it is imperative to use PEA biomass to improve the methane production yield than the whole cell biomass. Due to escalating price and unstable supply of fish meal (FM), alternative protein sources are used in aqua feed, however these sources do not meet to the requirement. The use of less expensive protein source in aquaculture feed as alternative to FM is required. Microalgae are primary producers in the food chain as well as a natural food for fish. Microalgal biomass is comprised of proteins, lipids, carbohydrates, pigments and many other bioactive compounds. The microalgal proteins have an appropriate balance of all essential amino acids, while lipids are rich in polyunsaturated fatty acids (omega-3 fatty acids, EPA, DHA). Whole algae contain all required ingredients while LEA also contain protein, carbohydrates, vitamins, bioactive compounds even though most of the lipid soluble nutrients have been removed. Thus, microalgae have promising potential to be used in aquaculture feed. Aquaculture production continues to increase globally, to meet the aquaculture feed demand algae supplemented aquaculture feed will play an important role in providing good quality fish. In this study, approximately 200 kg of microalgal biomass was harvested for the feed application. Due to lower toxicity, ease of availability and ease of recovery from mixture, hexane was used as a lipid extracting solvent at pilot scale to generate LEA. The 44 weeks (from juvenile to finisher stage) feeding trials were conducted to evaluate the effect of whole and LEA supplementation of S. obliquus strain on growth performance, disease tolerance, feed utilization, physiological activity, and fillet biochemical composition of Nile tilapia (Oreochromis niloticus). In the first trial, fish were fed with an algae free diet (control) and four experimental diets (2.5, 5, 7.5 and 10 wt%) as protein source of dried S. obliquus. The study showed that microalgae could be used as a protein supplement in the Tilapia feed for enhancement of morphological characteristics and nutritional value. The 7.5% and 10% supplementation of whole algal biomass in tilapia feed showed significant improvement in weight and length of the fish compared to the control. The daily body weight gain was 0.25 g higher in experimental groups than the control. The hepatosomatic index percentage was also higher in fish feed when 7.5% whole algae was used in fish feed as a protein source. The results also showed that 7.5% and 10% have better specific growth rate (1.57 and 1.5%), daily body weight gain (1.1 and 0.86 g), overall body weight gain (427.16 and 331.48 g), protein assimilation (43.96 and 40.46%) higher than the control diet fed fish. The survival rate of fish were 100% at every inclusion level. In second trial (44 weeks), two supplementations (7.5 and 10 wt%) of LEA as protein source were used in Nile tilapia diets. Results showed 7.5% and 10% LEA supplemented feed shown better growth performance than control. The protein content were 42.2%, 41.3% and 36.1% in tilapia fed with 7.5%, 10% LEA and control feed, respectively. The body weight gain, tilapia fed with 7.5% LEA shown 357 g while 10% LEA and control have 331.78 g, and 330.08 gm, respectively. The application of whole and LEA of S. obliquus in tilapia feed, shown appropriate supplementation level for tilapia feed at demonstration scale. This thesis presents advances in knowledge in the field of microalgae biorefinery research for pilot scale operations. This research work has covered various aspects such as effect of drying, cell disruption and lipid extraction on whole and LEA metabolites yield. The extraction of lipid from wet and dry microalgal biomass using various solvent systems provides a new insight for the selection of appropriate solvent systems, which can be used for the large-scale lipid extraction. The study on LEA for biomethane production enhances the understanding about the effects of different pre-treatments and product extractions on biomethane production. The results revealed that the supplementation of whole cell and LEA using S. obliquus for tilapia feed is safe therefore, can be used as an alternative protein source. The findings of this study have both academic and industrial value.
Application of thermostable a-Amylase from Thermomyces lanuginosus ATCC 58157 to nutritionally enhance starch based food
(2006) Padayachee, Thiriloshani
In Sub-Saharan Africa there is an urgent need to sustain and improve the quality of its food resources. Poverty eradication features high on the agenda of a number of world health organisations, while the number of underweight children in Africa continues to increase (Pellet, 1996). Providing nutritionally enhanced foods to the poor will help towards achieving this objective. Protein-energy malnutrition has been identified as one of the most important problems facing Africa, with maize as the staple diet (Nkama et al., 1995). However, a combination of several factors limits availability and the nutritional quality of maize. During starvation, energy and protein intakes decrease by 20-30%, with most of the children in Africa having an average protein intake of only 20 g per day (Igbedioh, 1996). Energy availability also affects protein utilization because of interrelationships of protein and energy metabolism (Elwyn, 1993). The diets of inhabitants in developing regions depend mainly on cereals (maize) for both protein and dietary energy which lacks indispensable amino acids, minerals, vitamins and carbohydrates. In light of these growing concerns an attempt was made to devise a scientific strategy to combat the nutritional shortfalls of maize meal. A multidisciplinary and concerted approach was followed within this project aimed at designing an improved thermostable amylase and applying the enzyme to nutritionally enhance maize meal. It was envisaged that the manipulation of maize meal, by the application of enzyme technology will improve the nutritional status of this staple food. The consequences is that an alternate solution for the eradication of an ailing, poverty stricken and malnourished African population is achievable. It is possible that the boundaries defining the limits of life will extend to even greater extremes through the application of novel technologies.
Assessment of microalgal ACCase and rbcl gene expression as a function of nutrient and metal stress
(2017) Singh, Poonam; Bux, Faizal; Kumari, Sheena K.; Guldhe, Abhishek
Microalgae are considered to be a potential feedstock for biodiesel production. However, the main concern with regard to the large scale microalgal biodiesel production process is its competence and economic viability. The commercial realization of microalgal biodiesel production requires substantial impetus towards development of efficient strategies to improve lipid yields upstream. Nitrogen (N) and phosphorus (P) stress during cultivation are the widely used lipid accumulation strategies for microalgae. However, these individual nutrient stress strategies are associated with compromised biomass productivity which hampers overall lipid productivity. Lipid enhancement strategies based on light, temperature and CO2 are associated with technological barriers for scale up and incur additional cost. Thus, the main aim of this study was to develop an integrated, easily applicable and scalable lipid enhancement strategy based on nutrients and metals such as N, P, iron (Fe), magnesium (Mg), calcium (Ca) and EDTA stress for selected indigenous microalgal strains. The effect of metal concentrations individually and in combination on microalgal lipids and biomass production is a scarcely exploited area. In this study, a novel approach involving individual as well as combined metals and EDTA stress under N and P limited conditions for lipid enhancement in microalgae was investigated. Microalgal growth physiology, photosynthetic performance, biochemical composition (lipid, carbohydrate and protein) and expression of selected key genes involved in photosynthesis (rbcL) and fatty acid biosynthesis (accD) were studied both under selected individual and combined stress conditions. Out of seven microalgal isolates obtained during the initial isolation and screening process, two strains were selected for lipid enhancement study based on their growth rates, biomass yields, lipid content and lipid productivities. The strains were later identified as Acutodesmus obliquus and Chlorella sorokiniana based on both morphological characteristics and phylogenetical analysis. The selected strains were thereafter subjected to different cultivation conditions involving varying metal, EDTA and nutrient stress conditions. A significant increase in lipid productivity was observed when the concentrations of Fe, Mg and EDTA were increased and Ca was decreased to degree in the N and P stress BG11 medium. For A. obliquus, a highest lipid productivity of 80.23 mgL-1d-1 was achieved with the developed strategy under limited N (750 mg L-1) condition which was 2.18 fold higher than BG11 medium and 1.89 fold higher than N limited condition alone. Similarly, for C. sorokiniana, highest lipid productivity of 77.03 mgL-1d-1 was achieved with the developed strategy under limited N (500 mgL-1) and P (10 mgL-1) which was 2.67 fold higher than BG11 medium and 2.35 fold higher than N and P limited condition alone. For both the microalgal strains, Fe was the most significant trace metal affecting their lipid productivity. These above observations were further confirmed through photosynthetic performance analysis and gene expression studies. At mid log phase, 6.38 and 5.15 fold increases in the expression levels of rbcL gene were observed under combined stress (OCMS+OE) as compared to the control (BG11) condition in A. obliquus and C. sorokiniana respectively. This also resulted in an increased expression level of accD gene involved in lipid biosynthesis to 10.25 fold and 9.79 fold in A. obliquus and C. sorokiniana respectively at late log phase. The results from expression studies of rbcL and accD genes were in compliance with biomass yields, photosynthetic performance, protein yield and lipid productivities for both the strains under different cultivating conditions. The universal applicability of the above strategy was confirmed by applying it to five other microalgae strains isolated in this study which resulted in considerable increase in their overall lipid productivity under optimized conditions. Attempts were made to scale up the lab scale study to open circular pond (3000L) cultivation for A. obliquus. Results showed a 2.08 fold increase in lipid productivity under optimized conditions compared to the control, which emphasizes the scalability of the developed strategy even under uncontrolled conditions. In conclusion, the developed combined metal and EDTA stress strategy not only assisted in alleviating the biomass productivity but also enhanced the lipid accumulation which resulted in overall increased lipid productivity under N and P limited condition. Furthermore, the improved carbohydrate and protein productivities observed with the developed lipid enhancement strategy make it suitable for biorefinery approach with multiple products. An improvement in lipid profile and high biodiesel conversion were also observed with this universally applicable and scalable lipid enhancement strategy confirming their potential applicability during large scale cultivation for biodiesel production.
Bioaugmentation with Bacillus spp. for bioremediation of synthetic wastewater using a fluidized-bed reactor
(2020-03-25) Roets, Yrielle; Bux, Faizal; Lalloo, Rajesh; Kumar, Sheena
South Africa’s freshwater resources, including rivers, man-made lakes and groundwater are under severe threat due to an ever-expanding population and economy, which is depleting these resources. The increase in population has a direct correlation with the increase in wastewater generated. The remaining fresh water resources need to be preserved therefore recycling of wastewater, to replenish our water supplies and preserve the environment, is a solution to the problem. For a developing country, it is important to use treatment methods that are cost effective and do not exert a negative impact on the environment, such as biological wastewater treatment options. One of the systems commonly used in biological wastewater treatment is the fluidized-bed bioreactor (FBBR) due to its advantages such as higher biomass concentration and a higher mass transfer thus resulting in a higher rate of biodegradation. This study focused on evaluating the efficacy of augmenting with Bacillus spp. to enhance the bioremediation of wastewater using a FBBR. Bacillus spp. used in this study were isolated from a municipal wastewater treatment plant (10 isolates) and the remaining three isolates were selected from the CSIR Bacillus database. The isolates (13 in total) were screened for 1) their ability grow in wastewater, 2) ability to reduce high concentrations of COD, ammonium, nitrates and phosphates in flask studies containing synthetic wastewater (SWW) and 3) ability to produce common enzymes such as amylase, cellulase, lipase and protease. Isolates showed varying bioremediation potential for different compounds analysed. Isolate B006 showed the highest phosphate removal rate (3.290 mg.L-1.h-1) where as D005 showed the highest growth rate (0.955 h-1), COD reduction rate (55 mg.L-1.h-1) and cellulase activity (5.485 mm) among all the isolates. Isolate D014 presented the highest ammonium removal rate (12.43 mg.L-1.h-1), amylase (5.00 mm) and protease (10.00 mm) activity whilst B001 displayed the highest nitrate removal rate (9.4 mg.L-1.h-1). The results for the individual assays were assessed and weighted in a matrix and the isolates that scored above 50% were selected for consortium studies. Four Bacillus spp. that scored above 50% in the scoring matrix were then evaluated for their ability to co-exist as a consortium. The consortium studies were then compared with results obtained for individual isolates. The selected Bacillus isolates were identified and assessed for their safety to the environment and to the end user. Identification was conducted using 16s rDNA sequencing and results showed that B006 identified as B. cereus, D005 as B. cereus and D014 as B. subtilis. Isolates, B006 and D005 were further assessed for enterotoxin production and the presence of anthrax virulent plasmids pX01 and pX02. After conducting the biosafety assays, the isolates were rendered safe for use. The isolates were then cryopreserved as spores in 25% glycerol and stored at -80 °C. The impact of the cryopreservation method and the storage conditions on the viability of the isolates was assessed after six months of storage and it was established that the isolates were still viable and that the method was adequate. The bioremediation potential of the consortium was further evaluated using a 17 L Pilot scale fluidised-bed bioreactor. The reactors were fed at three different flow rates of 1.5 L.h-1, 2 L.h-1 and 3 L.h-1 over steady state conditions (~3months). The results showed that the FBBR augmented with the selected Bacillus isolates, resulted in improved nutrient (COD, ammonium and phosphates) removal efficiencies compared to the non-bioaugmented control. The highest ammonium removal (62.8%) was observed at a flow rate of 1.5 L.h-1 (11.30 h retention time), whereby there was an overall 29.8% improvement in ammonia removal in comparison to the non-augmented control. Similarly, an overall improvement in phosphate (14.73%) was observed at a flow rate of 2 L.h-1 (8.48 h retention time) with 50% removal efficiency. The highest COD removal was observed at a flow rate of 1.5 L.h-1 (11.30 h retention time) whereby 74.5% COD was reduced with a 32.6% improvement when compared to the non-bioaugmented control. Our work has demonstrated the potential application of Bacillus as bioaugmentation agents to enhance wastewater treatment efficiency as a potential solution to water challenges in developing countries. This technology could also be utilized for addressing the challenges of a wider range of different effluents.
The design and development of software simulating interactive marine radar and electronic navigation instruments based on a PC platform
(1999) Cox, Kieron Michael Tesling; Stewart, M. J. M.
This study was intended to develop suitable software to emulate Marine Radar and other Electronic Navigation Systems found on Merchant,vessels. This equipment includes Radar with or without Automatic Radar Plotting facilities, Navstar Global Positioning Systems, Echo Sounders, Radio Direction Finder as well as Decca Navigator. Certain of these aids are required in the Radar Simulator Specifications [ref 1] to which the SAMSA - South African Maritime Safety Authority (formerly the South African Department of Transport) adheres. SAMSA is the authority which approves Maritime training and Simulators in South Africa in compliance with International standards as laid down by, IMO - International Maritime Organisation.
Design of a worksite intervention to lower cardiometabollc risk In South Africa
(2023-05) Singh, Shivneta; Naicker, Ashika; Grobbelaar, Hendrina Helena
Background: Non-communicable diseases (NCDs) continue to increase globally, with an unduly larger impact in low to middle income countries (LMICs). NCDs are the main cause of death worldwide. There is strong evidence that lifestyle changes, such as weight loss, increased physical activity, and improved diet quality can help avert or slow down type 2 diabetes and reduce cardiometabolic risk factors, for example, high blood glucose, plasma lipids, and blood pressure. Regardless of the verification of research data, supporting the use of lifestyle interventions to prevent diabetes (improve glucose tolerance and lower high blood pressure), and implementing interventions in real-life settings has been proven to be difficult. Aim: The purpose of the study was to guide the development of an acceptable, appropriate, and feasible worksite intervention targeting the food environment and behavioural intervention to reduce cardiometabolic risk at a worksite in South Africa (SA). Methodology: In this cross-sectional study both qualitative and quantitative methods were used. The capacity of the built environment was explored through structured observations of the food and physical environment to offer healthy food and promote physical activity. Semi-structured in-depth interviews (IDIs) were conducted with worksite managers and canteen managers to assess the appropriateness, acceptability and feasibility of changes at worksites and explore the perceptions, provisions, facilitators and barriers to healthy eating at the worksite environment. Purposive snowballing sampling was used to recruit worksite managers and canteen managers for the IDIs. Focus Group Discussions (FGDs) were conducted amongst employees to explore the perceptions, provisions, drivers of and barriers to healthy eating at the worksite. An Organisational Readiness to Implement Change (ORIC) questionnaire was administered face to face at the worksite canteens and online through emails to employees aged between 18 to 65 years to determine the worksite readiness to implement changes at the worksite. Canteen staff were approached to rate possible intervention components for the purpose of tailoring the interventions and identifying the best way to deliver the intervention. The interventions were rated by canteen managers or canteen staff on a scale from one to five with regards to the feasibility of implementing different components of the intervention: with one (1) being impossible to implement and five (5) being easy to implement. A scoping review was carried out to gather data from empirical findings on the categorisation of healthy foods through Front of Pack (FOP) labelling schemes and was reported using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) extension for Scoping Reviews (PRISMA-ScR) guidelines. Key findings from the formative work were used to select suitable food and physical environment interventions for the worksite. Worksite canteen intervention training was conducted to train canteen managers for the implementation of the food environmental intervention using the training manual that was developed by the researcher. Results: The study was conducted at six Unilever SA worksites, three in KwaZulu-Natal (KZN) and three in Gauteng province. The Unilever worksites comprised of five factories and one Head Office, namely, Unilever Maydon Wharf (Personal Care and Home Care), Unilever Indonsa (Savoury dry food plant - Knorr, Robertson’s, Rajah), Unilever Khanyisa (Home Care), Boksburg (Home care) and Lordsview (Ice cream -Ola) and La Lucia Head Office (Head Office). The study was also conducted at Retailability Head Office, a fashion apparel brand, which borders on the Unilever Head Office, making a total of seven worksites. The findings of the structured observations for the physical environment indicated that walking tracks were demarcated within the worksites; however, there were no signage prompts to encourage walking. Stairwells were clean, well lit, easily visible and accessible at each building; however, the health benefits of using the stairs were not displayed. The food environment was observed at six canteens including La Lucia Head Office and Retailability, Unilever Maydon Wharf, Unilever Indonsa, Unilever Khanyisa and Unilever Boksburg. There were two canteens at La Lucia Head Office: the main canteen and a coffee shop. There was no canteen at Unilever Lordsview, but there was a dining area with packaged food sold at the vending machine. Regarding the observation of the food environment, the worksite canteens offered five subsidised contract dishes among other unsubsidised dishes of which the healthy meal was the most expensive in a four-week menu cycle. Pre-made pre-packaged food options were sold at the canteens and displayed near to the point of sale. Ten semi-structured IDIs were conducted with worksite managers, to assess the appropriateness, acceptability and feasibility of changes at worksites and to explore the perceptions, provisions and facilitators of and the barriers to healthy eating at the worksite environment. Several themes emerged from the IDIs with worksite managers with regards to participation in a lifestyle intervention namely: availability, worksite resources and barriers to participation. Four semi-structured IDIs were conducted with canteen managers to assess the appropriateness, acceptability and feasibility of changes at worksites and barriers to healthy eating at the worksite environment. Numerous themes emerged from the IDIs with canteen managers including the enablement of a healthy food environment, information dissemination, employee preference and canteen enablers. Five FGDs were conducted, each group comprising of 4-6 employees, until data saturation was reached to understand the appropriateness, acceptability and feasibility of a range of possible changes at the worksite. Many themes emerged from the FGDs such as nutrient-dense foods, nutrient-poor foods and energy-dense beverages as well as the food environment and healthy longevity. Worksite readiness to implement change was determined through the ORIC questionnaire. The ORIC statements that Unilever employees agreed with most scored 4.51 on the scale of “I believe this change will benefit our worksite”, followed by 4.49 on the scale of “I am committed to implementing this change” and 4.41 on the scale of “I want to implement this change”. The lowest scores (disagreement) were 3.35 for “I have the equipment we need to implement this change”, 3.37 for “I have the resources we need to implement this change” and 3.46 for “I have the expertise to implement this change”. All statements were significantly different from ‘3’, on average. All mean values were >3 which indicates there was a significant agreement with all the statements. Factor analysis with promax rotation was applied to the 31 statements. A Kaiser-Meyer-Olkin Measure of Sampling Adequacy (KMO) of 0.958 and a significant Bartlett’s test indicated that the data was adequate for successful and reliable extraction. The alpha value for factor 1 and 2 was >.7, therefore indicating reliability. Composite variables were formed by calculating the average of the agreement scores for all items included in a variable. It was observed that there was a significant agreement for commitment (COM) and implementation (IMP) (with agreement that they desired the change and were committed to it being significantly higher than their agreement that they could implement the change). Results from a paired ttest showed agreement that they desired the change and were committed to it and were significantly higher than agreement that they could implement the change, t (299) = 15.229, p<.001. Further analysis to determine differences across worksites was conducted. Analysis from ANOVA showed that there was a significant difference in COM (commitment) across worksites, F (3, 296) = 5.375, p=.001. Post hoc analysis using Tukey’s test indicated that agreement to commitment was significantly higher at Maydon Wharf than at La Lucia Head Office (p=.043) and at Khanyisa (p=.021); and at Indonsa than at La Lucia Head Office (p=.031) and at Khanyisa (p=.021). Furthermore, there was a significant difference in IMP (implementation) across worksites, F (3, 296) = 9.960, p<.001. The ORIC statements that Retailability employees agreed with the most scored 4.58 on the scale: “I am committed to implementing this change”, followed by 4.53 on the scale of “I believe this change will make things better”, 4.50 on the scale of “I feel that implementing this change is a good idea” and 4.50 on the scale of “I feel this change is compatible with our values”. The lowest scores (indicating disagreement) were 3.11 for “I have the equipment we need to implement this change”, 3.24 for “I have the resources we need to implement this change” and 3.46 for “I have the expertise to implement this change.” All statements were significantly different from ‘3’, on average. All mean values were >3 which indicated there was significant agreement to all the statements. Factor analysis with promax rotation was applied to these 31 items. Two factors were extracted which accounted for 72.19% of the variance in the data. A Kaiser-MeyerOlkin Measure of Sampling Adequacy (KMO) of .784 and a significant Bartlett’s test indicated that the data was adequate for successful and reliable extraction. The alpha value for factor 1 and 2 was >.7, therefore indicating reliability. It was observed that there was a significant agreement for commitment (COM) and implementation (IMP) (with agreement that they desired the change and were committed to it being significantly higher than their agreement that they could implement the change). Results from a paired ttest showed that agreement that they desired the change and were committed to it was significantly higher than agreement that they could implement the change, t (37) = 6.727, p<.001. The intervention rating scale was completed by 12 canteen managers and canteen staff using a scale from one to five for the feasibility of implementing different components of the intervention. Interventions that were easy to implement were reported by 100% (n=12) of participants for increasing fruit and vegetable choices, 92% (n=11) for the provision of free water, followed by 75% (n=9) for the addition of a salad bar and ready-to- eat healthy meals. The one-sample t-test was done to determine whether the average ‘implementability’ score differed significantly from the central score of ‘3’. The easiest interventions to implement were reported by 83% (n=10) of participants being the strategic positioning of healthier alternatives to make healthy items more accessible with 75% (n=9) recommending traffic light labelling and healthy option stations. The most difficult to implement was reported by 25% (n=3) of participants for the display of kilojoules of a product translated into the number of minutes to perform a certain physical activity. A scoping review was conducted on FOP labelling schemes to inform the selection of a FOP labelling scheme best suited for canteen foods at worksites in SA. Several articles (n = 2513) were identified and screened after excluding duplicates (n = 2474). Overall, 1347 articles were excluded from the study because their abstracts and titles did not match the qualifying criteria. A total of six articles was used in the qualitative analysis after a full-text review of the remaining articles. It was concluded that grading foods into categories of healthfulness through evidence of key nutritional dimensions is a practical tool to inform food environmental interventions that may assist in public health promotion by influencing consumer choice in workplace canteens and beyond. The results from the observations, IDIs, FGDs, ORIC questionnaire, canteen rating intervention scale and scoping review were used to guide the development of the physical and canteen intervention and canteen staff were capacitated with training to implement the food environment intervention. A list of interventions detailing the tools to be used and responsibilities for executing the six weeks’ intervention with two weeks’ maintenance classes for phase three of the study, titled the South African Pioneer Worksite Multicomponent Lifestyle Intervention Study (WMLIS) was developed by the research team. Conclusion: Interventions are a useful tool that can be used in worksite settings to improve employees' overall occupational well-being. Interventions targeting the food environment and behavioural intervention can promote healthy eating behaviours and reduce cardiometabolic risk. It is important to take into account organisational complexity and the built environment when designing an intervention. In this study, formative research methods were used to engage worksite stakeholders to develop an intervention plan that is both theoretically and practically grounded to foster institutionalisation of the intervention. The findings of this study was used to contextualise and guide the development of acceptable, appropriate and feasible worksite food environment and behavioural intervention to reduce cardiometabolic risk among South African employees. The methods used allows for drawing of general conclusions for the implementation of lifestyle and food environment changes at worksites in SA. It is recommended that the study should be scaled up to other worksites to determine the comparativeness of this study to the response of other worksites regarding the acceptability, appropriateness and feasibility of worksite interventions.
Development and acceptability of a cost-effective, energy-dense snack suitable for the National School Nutrition Programme
(2020-11-13) Hassanally, Saffia; Naicker, Ashika; Singh, Evonne
Background: The National School Nutrition Programme (NSNP) was established in South Africa (SA) to ensure that hunger will not be a barrier to learning among school learners attending quintile one to three schools and aims to provide a free, nutritious meal for all 189 school days. The NSNP currently does not have a solution to ensure that all learners are suitably sustained until the main NSNP meal can be served. With the increase in food insecurity levels, the need for the development of an energy-dense snack item for school learners is critical, in the effort of combatting hunger and ensuring learners have the necessary energy to sustain their concentration until their next meal. Aim: This study aimed to develop a suitable, cost-effective, energy-dense snack item for learners as a supplement to the NSNP, to assist learners in reaching their recommended dietary requirements. Methodology: The snack product development was informed by a cross-sectional snack preference survey, as well as a scoping review of the literature on school feeding programmes and past snack interventions that have shown success in South Africa and other developing countries in Africa. Through informed consent, 85 primary school learners between the age group of nine to thirteen that were part of the NSNP from two quintile three schools in KwaZulu-Natal participated in the snack preference survey whilst 81 learners participated in the consumer sensory evaluation. The snack preference survey and scoping review of past snack development interventions were conducted, to decide on a suitable, cost-effective snack for development, for the learners of the primary schools. The developed snack product then went through sensory evaluation, using trained personnel and, thereafter, for microbiological testing, to deem the product safe for consumption. The product then underwent nutritional analysis, to determine the nutritional properties of the snack item and shelf-life testing. Lastly the product was presented to the learners for final sensory analysis, to determine sensory acceptability of the developed snack, using a 7-point facial hedonic scale. Results: Analysis of the reviewed articles inferred that the most appropriate snack product to develop for this study was a biscuit. Results from the snack preference survey showed that muffins were the most preferred snack (57.1%) by both girls and (55.8%) boys, respectively. Biscuits were the second most preferred snack (32.6%) by both girls and (33.3%) for boys, respectively. There was no significant relationship between gender and choice of snack (p=1.000) and no significant relationship between age and choice of snack (p=0.141). The literature results showed biscuits to have a longer shelf life than most other snacks. It can be emulated with ease and can carry many nutrients, while being cost-effective. Trained sensory panellists, comprising of consenting Food and Nutrition staff and students, were used to evaluate the sensory acceptability of the trial recipes, during development. Following the systematic steps of food product development, at the end of the trained sensory tests, a crispy, flavourful biscuit was developed. The final recipe yielded 20 portions of 22g biscuit dough, of which the final weight of the biscuit was reduced to 20g, due to moisture loss during baking. The microbial analysis deemed the product to be safe to consume, as total counts of coliform bacteria were zero, showing no bacterial growth. The nutritional analysis showed that fat contributed the most energy (61.0%). The Recommended Dietary Intake (RDI) percentage values of the biscuit amounted to 14.3% for girls and 14.2% for boys, which is in-keeping with the first objective of creating an energy-dense product. When compared to two other products of a similar nature on the market, the developed biscuit was found to be the most cost-effective (R0.79 for 20g portion). The shelf stability of the product proved that the product is highly shelf stable, remaining fresh for five weeks and can last up to five months, under proper storage conditions. Following the consumer sensory evaluation, a significant number (69.1%) of children found the snack to be ‘Super good’ (p<.0005), 14.8% rated the product as ‘Good’ and 12.3% rated the product as ‘Really good’. There was no significant difference in sensory scores across age groups (p=0.706). Conclusion: It is well established that school feeding programmes create a positive impact on school children, as it enriches their lives and provides them with much needed nutrients. In SA, the well-established NSNP does have challenges one of which is the shortfall of -providing 30.0% of the Recommended Dietary Allowances (RDA) to learners. Although there are existing snack development studies, this study is unique, in the sense that it is designed to assist the NSNP to fill the current gap in the RDA for the children of SA. All objectives of this study were reached, and a suitable, cost-effective, energy-dense snack biscuit was developed in a systematic process. This snack can be a potential solution to sustain children that come to school hungry. This study will be brought to the attention of NSNP stakeholders, in the hope of the programme adopting this solution, to fill the RDA gap in the NSNP.
Development and optimization of technology for the extraction and conversion of micro algal lipids to biodiesel
(2015) Ramluckan, Krishan; Moodley, Kandasamy Govindsamy; Bux, Faizal
Fossil fuel reserves have been diminishing worldwide thus making them very scarce in the long term. These fuel sources and their by-products which are used commercially tend to produce large quantities of emissions. Some of them are believed to be toxic to flora and fauna. It is primarily for this reason that researchers worldwide have begun to seek out alternative sources of environmentally safe fuel. Biodiesel from algae is one of these sources that have been examined over the last few decades. Biodiesel has been produced from other plant-based material and waste oils in countries like America and Japan. However, the use of food based crops for biodiesel production has been challenged as it has an impact on food production on an international scale. Algae have only recently been investigated for their feasibility for biodiesel production on a large scale. The aim of this study was to investigate and develop technologies for biodiesel production from algae. The species of algae chosen were chlorella sp and scenedesmus sp., since they are indigeneous to Kwazulu Natal in South Africa. Samples were obtained from a local raceway pond and prepared for analysis. Drying protocols used freeze, oven and sun drying for initial preparation of the samples for analysis. Sun drying was the least energy intensive but most time consuming. At laboratory scale, oven drying was chosen as the best alternative. Lipid extraction methods investigated were the separating funnel method, the soxhlet method, microwave assisted extraction (MAE) and the expeller press. Thirteen solvents covering a range of polarities were used with the extraction methods to determine the efficiency of the solvent with these methods. Optimization of the MAE method was conducted using both the one factor at a time (OFAT) method and a design of experiment (DOE) statistical method. The shelf life of algal biomass was determined by ageing the samples for approximately three months. Direct and in-situ transesterification of lipid extracts to produce biodiesel was investigated using both acid and base catalysis. Qualitative and quantitative analyses were conducted using Fourier transform infra-red (FTIR) and gas chromatography (GC). Chemical and physical characterization of the biodiesel produced from the algal lipid extracts were compared to both local and international standard specifications for biodiesel. In terms of extraction efficiency, it was found that soxhlet and microwave assisted extraction methods were almost equally good. This was proved by the MAE method yielding an average of 10.0% lipids for chloroform, ethanol and hexane after 30 mL of solvent was used in an extraction time of 10 minutes, while the soxhlet method yielded 10.36% lipids using an extraction volume of 100 mL of solvent with an extraction time of 3 hours. Chloroform, ethanol and hexane were more efficient than the other ten solvents used. This was shown by these three solvents producing lipid quantities between 10% to 11% while all the other solvents produced lipid quantities between 2 and 10 %. The best extraction efficiency was achieved by the binary solvent mixture made up of chloroform and ethanol in a 1:1 ratio. Under the conditions optimized, this solvent ratio yielded a lipid content of 11.76%. The methods chosen and optimized for extraction are very efficient, but the actual cost of production of biodiesel need to be determined. Physical methods like the expeller press are not feasible for extraction of the type of biomass produced unless algae are pelletized to improve extraction. This will impact on the cost of producing biodiesel. The transesterification protocols investigated show that the base catalysis produced biodiesel with a ratio of saturates to unsaturates conducive to a good fuel product. The direct esterification method in this study proved to be better than the in-situ method for biodiesel production. The in-situ method was also more labour intensive. Chromatography was found to be a fast and efficient method for qualitative and quantitative determination of biodiesel. Characterization tests showed that the quality of biodiesel produced was satisfactory. It also showed that the methods used in this study were feasible for the satisfactory production of biodiesel which meets local and international specifications.
Development of a community engagement capacity building programme within a social justice framework for Consumer Science Food and Nutrition students at the Durban University of Technology
(2017) Grobbelaar, Hendrina Helena; Napier, Carin E.; Maistry, Savathrie
The focus of this study is to develop a capacity building programme that prepares students for service learning (SL) with the purpose of developing social responsibility and active critical citizenship underpinned by a social justice paradigm at a University of Technology (UoT). In developing countries such as South Africa that still experience severe injustices and inequality of access to, for example, certain services such as health services, it is impossible to ignore issues of human and social development and poverty reduction when promoting the university’s role in development. The developmental role of HEIs has been reinforced through the introduction and formalization of Community Engagement (CE) as a core function of higher education together with teaching and learning and research. When examining the role of universities in educating students for social responsibility and critical citizenship, it is evident that the biggest area of growth of CE has been in the form of Service Learning (SL) and community service. The study posits that in the South African context of HEIs, the potential for fostering, specifically critical discourse and creative thinking exists in what are termed as traditional universities because of the nature of the varied disciplines offered at these institutions. On the other hand, UoTs focused predominantly on the technical study field and on training students for the market place. The emphasis on Work Integrated Learning (WIL) and industry placements narrowed the focus and excluded insights into South Africa’s diversity and socioeconomic issues in the curriculum. The concept of social responsibility within a social justice paradigm is a foreign concept at UoTs in particular. To facilitate SL within a social justice paradigm and to address issues of injustice and inequality in SA at universities, the question that needs to be asked is: how should the preparation of students be shaped to adequately prepare them to become justice-orientated, socially and civically responsible students without compromising their work preparedness? This bigger question leads to the specific question of the study, which is: if the department of Food and Nutrition Consumer Sciences at the Durban University of Technology (DUT) is to develop justice orientated, socially and civically responsible students, what theoretical and philosophical considerations should guide the development of a SL capacity building programme? To achieve the purpose of the study the following objectives were identified: firstly, establish the effectiveness of the current preparation of Food and Nutrition students for SL to foster justice-orientated social and civic responsibility; secondly, determine the theoretical and philosophical considerations that should guide the development of students’ justice-orientated social and civic responsibility through SL in the field of Food and Nutrition; thirdly, develop and implement a SL capacity building programme to foster social responsibility and critical active citizenship within a social justice paradigm; finally, develop a framework for a social justice-orientated SL capacity building programme post evaluation A sequential exploratory mixed methods research protocol was applied in this study. The research process consisted of three phases. Phase I entailed the exploration of the research question with qualitative data collection (focus groups) and analysis. This phase was followed by a developmental phase (Phase II) during which the qualitative results and the theoretical and philosophical considerations evident in the literature were used to develop a capacity building programme. The programme was implemented and the impact of the programme was evaluated in Phase III through the application of the Civic Attitudes and Skills Questionnaire (CASQ). Purposeful sampling was applied in Phases I (qualitative phase) and III (quantitative phase). During phase I five focus groups were conducted (n = 43). Phase III sample consisted of two groups namely, the experimental group (n = 19) and a control group (n = 24). Focus group interviews were recorded and transcribed verbatim after which the data was coded followed by a thematic analysis. The data from the CASQ was captured on Microsoft Excel® and analysed according to CASQ scales using the Statistical Package for Social Sciences (SPSS) version 23 to determine mean and standard deviations. A paired sample 2-tailed t-test was used to determine statistical significant differences between the pre- and post-test. Results from phase I confirmed students’ understanding of CE is mostly a charitable view with little emphasis on addressing social justice issues. The results showed that SL as currently planned and executed seems to perpetuate and reinforce existing social hierarchies and paternalism. The most common expectation of participating in CE from students was to apply skills and theoretical knowledge in a community setting. Students also commented that they expected to be developed personally and to learn about others. Additionally, it is evident from the results that students did not indicate any changes in their social justice awareness. The programme developed in phase II was within the framework of four dimensions including self-awareness, awareness of others, awareness of social issues and change agent as critical to preparing students for SL with the purpose of fostering social responsibility and active critical citizenship within a social justice paradigm and guided by the Ubuntu philosophy, Freire’s critical pedagogy and Mezirow’s transformative learning theory. The results of phase III showed that the experimental group who participated in the capacity building programme showed a significant increase in the social justice related subscales indicating their intentions of future civic action and change in social justice attitudes. The results in the control group demonstrated a decrease in the mean values in the post-test for the social justice subscales. The experimental group also showed an increase in the interpersonal and problem-solving skills, leadership skills, diversity attitudes and course value subscales but it was not significant. An opposite pattern was demonstrated in the control group with significant decreases in the interpersonal and problem-solving skills, leadership skills, diversity attitudes and course value. The results showed the significant impact of the capacity building programme on students’ awareness and understanding of social justice issues. Overall, the findings of the various phases assisted in refinement of the framework for a social justice orientated SL capacity building programme. The developed framework consists of five key components: philosophy that guides social justice oriented service learning; theories that underpin service learning; a pedagogy that would effectively enhance a social justice oriented SL experience; and praxis that integrates theory and practice.
Development of a sensorially acceptable food product from Cissus quadrangularis to create awareness among young adults
(2021) Singh, Vihara; Naicker, Ashika; Palmer, Karina
Among the main causes of food insecurity in Africa is drought which results in poor harvests for farmers. Drought tolerant plants are environmentally sustainable and show great promise in improving food security and preventing malnutrition. South Africa has a wide range of drought tolerant indigenous plants that possess both medicinal and nutritional value. However, most of these indigenous plants are used by older generations and are unfamiliar to younger generations. With the revival of indigenous knowledge systems and botanical decolonisation, the potential of indigenous plants as functional foods has come to the fore. Aim: The aim of this study is to develop a sensorially acceptable food product with Cissus quadrangularis and to create awareness of Cissus quadrangularis among young adults. Methodology: This food product development study was informed by key informant interviews as well as a desktop study on food and nutrition trends. Through informed consent, ten elderly community members participated in the key informant interviews and shared their knowledge, uses and perceptions of Cissus quadrangularis. The developed food product underwent pilot and final sensory evaluation through a 9- point hedonic scale and a paired preference test. For the sensory evaluation, 110 participants were used, 10 for the pilot and 100 for the final sensory evaluation. The food product also underwent microbiological testing, nutrient analysis, and shelf-life testing. Once this was conducted, an awareness tool was developed. The awareness tool underwent pilot and final evaluation via a Likert scale. For the awareness tool survey, 110 young adult participants residing in KZN were used, 10 for the pilot and 100 for the final instrument. Results: Analysis from the key informant interviews indicated that the participants viewed Cissus quadrangularis as a medicinal plant, used to treat sprains, inflammations, broken bones, cholesterol, and ulcers. The participants cooked the plant in curries, pastes or fried doughs and some participants boiled it and drank the water. The desktop study on food and nutrition trends displayed key food trends for 2019 and 2020 such as zero-waste foods, botanical beverages, alternative ingredient, sustainability, plant-based foods, and natural remedies, less sugar, health convenience items, and texture. The results from the key informant interviews and desktop study on food and nutrition trends informed the development of the food product with Cissus quadrangularis. Following the steps of product development, a trendy energy bite infused with Cissus quadrangularis was developed. The energy bite yielded 10 portions of 21.5g each. Analysis from the microbial test indicate that the microbial count in the product was high averaging between 1000 to 5000 cfu/g which was within acceptable limit. However, the product was suitable for a short shelf-life of three days. Potassium sorbate was added to the energy bite infused with Cissus quadrangularis for the second microbial test. The second test results indicated that the microbial count found in the developed product was low and that there were no microorganisms present. The Cissus quadrangularis infused energy bite (both samples) indicated that the product was to some extent high in sugar (4g: 3.4g / 6g: 3.48g per 21.5g). The nutrient analysis showed that the product was relatively low in fat and sodium. The energy bite carbohydrate level was relatively low as it contributed (Women: 6.72 %/ Men: 6.32%) to the Dietary Reference Intake (DRIs) of women and men aged 19-30 years old. The amount of dietary fibre present in this study; in both samples was high (4g: 4.02 / 6g: 4.16 per 21.5g), contributing well to both women and men DRIs of dietary fibre, respectively (Women: 16.08 % / Men: 10.94%). The protein value in the energy bite was significantly low only contributing Women: 3.17% / Men: 2.6% to the DRIs of women and men, respectively. The vitamins and minerals tested in the nutrient analysis were not present in notable amounts, contributing low percentages to both women and men’s DRIs. Analysis from the pilot and final sensory evaluation showed that both the 4g and 6g sample of the developed food product was liked, however, the 4g sample was preferred. The final sensory evaluation showed that 27% of participants chose “like extremely” for the 4g sample whilst 18% of participants chose “like extremely” for the 6g sample. The Wilcoxon signed ranks test indicated that there was no significant difference between the 4g and 6g sensory rating score (p=0.066) indicating that there was a marginal preference of sample 1 (4g) over sample 2 (6g). There was no significant difference in the sensory rating of these products across gender for the 4g (p=0.521) and 6g (p=0.673) sample. The last objective of the study was to develop an awareness tool using the developed food product to create awareness of Cissus quadrangularis among young adults. The pilot and final awareness tool survey showed that the majority of participants found the awareness tool to be informative and that the participants involved were willing to make the recipes using Cissus quadrangularis. The final awareness tool results indicate that a significant 93% either liked or extremely enjoyed the video (p<.0005). Analysis with Pearson’s chi-square (Fisher’s exact test) of the cross-tabulation of responses with demographics shows that there was a significant relationship between gender and video rating, Fisher’s exact = 11.129, (p=.007). The results indicated that 57.1% of male participants extremely enjoyed the video whereas 59.3% of females only liked the video. Conclusion: The development of a trendy and sensorially acceptable food product with Cissus quadrangularis as a main ingredient and the development of an awareness tool created awareness to this unfamiliar indigenous plant with various health benefits among young people. Food product development using indigenous edible plants can be seen as sustainable measure and can contribute towards food security initiatives in South Africa. Awareness tools that appeal to the youth can help educate young adults on various indigenous foods reducing the vulnerability of food and nutrition insecurity.
Electrochemical enzymatic biosensing of neotame in sweeteners by experimental and computational methods
(2020) Lephalala, Matshidiso; Bisetty, Krishna; Kanchi, Suvardhan; Sabela, Myalowenkosi I.
An enzymatic biosensor comprises of an enzyme, which recognizes and then reacts with the target analyte producing a chemical signal. In this type of sensor, an electrode is a key component that is employed as a solid support for the immobilization of biomolecules and electron movement. This work focuses on two case studies to assess the signal enhancing strategy that can potentially be used to quantify Neotame (NTM) in food and non-alcoholic beverages. The first case study involves a highly sensitive electrochemical enzymatic biosensor for the detection of NTM in the soft drinks developed, based on multiwalled carbon nanotubes (MWCNTs) decorated with aloe vera-derived gold nanoparticles (AuNPs) and carboxylesterase (CaE) enzyme. This electrochemical biosensor showed high sensitivity with a limit of detection (LOD) and limit of quantification (LOQ) of 27 μg L-1 and 83 μg L-1, respectively. The calibration plot revealed a linear dependence of the cathodic peak current on the NTM concentration profile with anR2 of 0.9829, indicating an improved electrocatalytic property of the glassy carbon electrode. The viability of the proposed strategy was confirmed by assessing the interactions between the enzyme and the analyte using computational methods. The density functional theory (DFT) calculations of NTM showed a HOMO–LUMO energy gap of -0.46618 eV, indicating that NTM can act as a good electron donor. Moreover, adsorption and enzyme-analyte docking studies were carried out to better understand the redox mechanism. These outcomes showed that NTM formed hydrogen bonds with LEU 249, GLU251, and other amino acids of the hydrophobic channel of the binding sites, making it easier for the redox reaction to take place for the detection of NTM. The results confirmed that the aloe vera-derived AuNPs are good platforms for immobilizing CaE because of their high surface area, encouraging an electron transfer from NTM to form a substrate-enzyme complex, contributing to improved biosensing signals. The second case study deals with an enzymatic biosensor developed, based on graphene oxide (GO) anchored with honey-derived nickel nanoparticles (NiNPs) and alcohol oxidase (AOx) enzyme. The biosensor showed high sensitivity with a limit of quantification (LOQ) of 47 μg L-1 and a limit of detection (LOD) of 15 μg L-1, respectively. The calibration curve of the cathodic peak current on the analyte concentration profile showed an improved electrocatalytic property with an R2 of 0.9926. The interactions between the enzyme and analyte were assessed using computational tools to confirm the viability of the proposed biosensor. A HOMO– LUMO energy gap of -0.46618 eV was confirmed using density functional theory (DFT) calculations, this suggested that NTM has great potential to act as an electron donor. Analyte-enzyme and adsorption docking studies were carried out for a better comprehension of the redox reaction mechanisms. These outcomes indicated that NTM forms hydrogen bonds with TRP 47, ARG 56, VAL 328, PRO 55, and other amino acids, thus assisting the redox reaction for the determination of NTM. The results confirmed that the honey-derived NiNPs have a high surface area, which acted as a good platform to immobilize AOx so that the electrons can be transferred from NTM to form a substrate-enzyme composite to give out an improved biosensing signal. Moreover, the magnified catalytic activity of these two biosensors for the determination of NTM in soft drinks showed great potential in the beverage industry.
Elemental determination of lubricating grease using ICP-OES
(2015) Marume, Cathrine; Govender, S.; Redhi, Gyanasivan Govindsamy
The focus of most lubricating grease testing has been based on performance and appearance rather than determining the concentration of chemical components. The primary reason being lubricating grease is a difficult matrix to work with from the perspective of the analytical laboratory. The purpose of this study was to develop a simple, reproducible method for elemental determination in lubricating grease and to apply the developed method to work out a flushing procedure for the filling lines in a grease manufacturing plant. The first part of the experimental work focused on developing a suitable and efficient sample preparation technique. Three techniques were explored: direct dilution, microwave assisted acid digestion and emulsification. Direct dilution involved shear mixing the lubricating grease with metal free base oil and diluting it with an organic solvent. Use of these solvents caused plasma destabilization or even plasma extinction and their use posed health risks for laboratory personnel. Microwave digestion involved mineralising the lubricating grease using an optimised microwave assisted acid digestion procedure. In the third sample preparation technique, microemulsions were formed by mixing the lubricating grease with a relatively small volume of a strong mineral acid mixture followed by the surfactant (triton X-100) at room temperature and pressure (RTP). This approach does not require the destruction of the organic matter or the use of large amounts of organic solvents. For all three techniques the sample was subsequently analysed for Al, B, Ba, Ca, Li, Na, S, Mo and Zn. All analysis was performed using an Optima ICP-OES with previously optimised parameters. The direct dilution method gave the most inconsistent results with relative standard deviation (RSD) as high as 56% for calcium, 79% for boron and 66% for lithium. Microwave digestion and emulsification gave comparable results, with the calibration curves of oil emulsions not differing significantly from aqueous ones. For microwave assisted acid digestion the limits of detection ranged from 0.028 mg/L for sodium to 0.255 mg/L for boron. Correlation coefficient values (r2) of all the elements were greater than 0.99. Likewise the limits of detection for emulsification ranged from 0.03 mg/L for aluminium to 0.37 mg/L for sulphur. The correlation coefficients for all the elements were greater than 0.99 and this indicates that the calibration curves were sufficient for analysing the digested grease samples. Five quality assurance samples were analysed using both methods and in addition a t-test performed at the 99.9% confidence level and 4 degrees of freedom showed that the two sample preparation techniques gave similar results. Emulsification has several advantages over microwave digestion technique and superior analytical performance over direct sample dilution using solvents, and hence was chosen as the method of choice for routine analysis of lubricating grease. The second part of the experimental work focused on developing a flushing procedure for filling lines in a lubricating grease plant. A flushing procedure is essential in order to minimise waste, which will in turn minimise production costs and avoids incurring disposal costs. In this series of experiments, the microwave digestion sample preparation technique was utilised for the subsequent determination of the flushing mass required in between product changes. The flushing procedure was implemented and monitored by the use of statistical quality control tools for a specified period of time, and as indicated by Shewart Control charts, the process was in statistical control.
Evaluating the sustainability of waste substrates for microalgal biomass production using different modes of cultivation
(2018) Ramsundar, Prathana; Bux, Faizal; Guldhe, Abhishek
The utilization of wastewater as a substrate for microalgal biomass cultivation is one of the few potentially viable routes for fuel and feed applications. In this study, the suitability of various liquid wastewater streams and waste biosolids from a domestic wastewater treatment plant was assessed for microalgal cultivation. The wastewater substrates were analyzed for nutrient content as a potential growth medium. For liquid waste substrates, physical, thermal and biological pre-treatment methods were evaluated to minimize the bacterial load. Biomass, physiology, nutrient removal efficiencies and biochemical constituents of Chlorella sorokiniana were investigated in influent (INF) and anaerobic tank centrate (AC) under mixotrophic (Mixo) and heterotrophic (Hetero) cultivation modes. Mixotrophic cultivation conditions demonstrated efficient ammonium (94.29%) and phosphate (83.30%) removal with promising biomass (77.14 mgL-1d-1), lipid (24.91 mgL-1d-1), protein (22.36 mgL-1d-1) and carbohydrate (20.10 mgL-1d-1) productivities. Urea supplementation (1500 mgL-1) further enhanced biomass (162.50 mgL-1d-1), lipid (24.91 mgL-1d-1), protein (22.36 mgL-1d-1) and carbohydrate (20.10 mgL-1d-1) productivities in Mixo AC. Therefore, the urea supplemented Mixo AC approach for microalgal cultivation was developed as a suitable biomass production strategy. This work also elucidated a novel algae cultivation strategy for utilisation of waste biosolids, where nutrient-rich waste activated sludge (WAS) and final effluent (FE) from the wastewater treatment process was used for microalgal biomass generation. This strategy reduced the use of synthetic nutrients, fertilizers and freshwater which contribute significantly towards the overall cost of biomass production. Strategy development included the investigation of physical, thermal and chemical pre-treatment methods to assist in effective nutrient release and bacterial load reduction. Evaluation of growth kinetics, photosynthetic performance, nutrient removal efficiencies and biochemical composition of microalgae under mixotrophic and heterotrophic modes of cultivation were performed. Furthermore, urea supplementation was studied to improve biomass productivity. Microalgae cultivation in acid pre-treated (pH 2) WAS + FE with urea supplementation (1500 mgL-1) showed enhanced biomass productivity of 298.75 mgL-1d-1. Microalgal biomass grown with WAS + FE using the developed strategy exhibited greater lipid (72.95 mgL-1d-1) and protein (72.84 mgL-1d-1) productivities and comparable carbohydrate yields (73.07 mgL-1d-1) to that of synthetic media. Thus mixotrophic mode of cultivation coupled with urea supplementation to WAS + FE proved to be a suitable cultivation strategy for C. sorokiniana. The study developed an efficient strategy to utilize AC and WAS + FE as a growth medium for microalgae. Furthermore, findings from this study have demonstrated the potential of waste streams and waste solids from domestic wastewater treatment plants for microalgal biomass generation
Evaluation of nutrition information embedded in the grade 8 to 12 KwaZulu-Natal school curriculum
(2016) Naidoo, Thilavathy; Napier, Carin E.
There is a lack of information and research on nutrition content in the curriculum for learners at the secondary school level. While nutrition content is addressed in the curriculum for Grades 8 and 9 in Natural Science, Social Science and Life Orientation, not all aspects of nutrition education are included. In Grades 10 to 12, nutrition content exists in Life Orientation, Agricultural Science, Agricultural Technology, Design Studies, Civil Technology, Electrical Technology, Mechanical Technology, Dance Studies, Information Technology, Consumer Studies and Hospitality Studies, however, not all learners are exposed to the learning areas that contain nutrition content. An important consequence of this lack of exposure to information on nutrition content is that learners who leave school after Grade 12 with inadequate nutrition knowledge potentially become adults who suffer from lifestyle diseases. This study focused on the nutrition content in the curriculum in Grades 8–12 in Kwa-Zulu-Natal in order to: evaluate the content in the curriculum referring to nutrition and to analyse the critical and developmental outcomes of nutrition education;. assess the nutrition knowledge of learners in Grades 8–12 in the Durban Central area (for the purpose of following a healthy lifestyle); determine the views of educators on the inclusion of nutrition content in the curriculum; highlight the importance of applying nutrition content in the curriculum to educate learners on disease prevention and good eating habits. The design of the study was evaluative, analytical and descriptive, and adopted both the quantitative and qualitative methodologies. The purposive sampling method was utilised for the selection of sample. The study was located in Central Durban and the sample comprised of boys and girls in Grades eight–12 at Durban High School and Ridge Park College, respectively. The sample included 343 boys and 360 girls who participated in the study. In order to establish the views of educators who teach nutrition knowledge in the curriculum, the study also included 134 educators purposively selected from 15 schools in the Umlazi District in KwaZulu-Natal. Two sets of instruments were used for data collection. The Nutrition Knowledge Questionnaire (NKQ)(previously developed) was used to determine the nutrition knowledge of learners in Grades eight–12 and across genders in both schools. An Educator Questionnaire (EQ) (developed for the study) on the learning areas that contained nutrition content was utilised to measure the extent to which the educators teaching those learning areas completed the curriculum content on nutrition. The Educator Questionnaire was used to ascertain the educators’ views on the importance of nutrition knowledge. The results of the research showed that the content dealing with nutrition in the school curriculum for Grades eight–12 was inadequate in certain learning areas to adequately educate learners on nutrition for the purpose of following a healthy lifestyle. The compulsory learning areas that contain aspects of nutrition knowledge were Life Orientation, Natural Science and Social Science for Grades eight and nine. In Grades10 to 12, Life Orientation is the only compulsory learning area that contains aspects of nutrition knowledge content. Nutrition knowledge investigation showed that learners are not adequately prepared in respect of all aspects of nutrition knowledge when they leave school at the end of Grade 12. The curriculum analysis of the learning areas in Grades 10 to 12 showed that the learning areas that contain nutrition knowledge are specialist learning areas not offered at all schools in the Durban Central area. The Educator Questionnaires showed that learning areas that include nutrition content in Grades 10 to 12 are not offered at all schools, thus probably negatively impacting on the learners’ level of nutrition content. The results of the Educator Questionnaire reinforced the notion that the curriculum for nutrition education was inadequate. The research concluded that the curriculum does not prepare learners adequately in respect of all areas of nutrition knowledge to enable them to follow healthy lifestyles. The results revealed that there is a correlation between the nutrition knowledge of learners and certain nutrition education aspects in the curriculum. Such results showed that the total mean scores for all the Food Based Dietary Guidelines ranged from 62.0% as the lowest, to the highest total mean score of 72.0%. However, the scores are low in critical areas of nutrition knowledge when individual scores are taken into consideration. An important consequence is that learners who leave school at the end of Grade 12 with inadequate nutritional knowledge become adults with the potential to suffer from lifestyle diseases. It is recommended that a compulsory learning area for all grades that deals exclusively with health, physical education and nutrition be introduced into the curriculum to assist learners to follow healthy lifestyles during and after school.
Fishing and fish consumption contributing to the nutrient profile, dietary diversity and food security of adult caregivers in a coastal community in Rivers State, southern Nigeria
(2019-06) Legbara, Kadi Prudence; Napier, Carin E.; Hart, A.
Introduction: The contribution of fishing practices and fish consumption to food and nutrition security cannot be over emphasized, particularly where large numbers of people are poor. Nutrition research has identified fish and fishery products as key components of human nutrition as well as one of the essential foods to incorporate into daily dietary food consumption based on its potential health benefits. These benefits have promoted the consumption of fish in recent times. Fish contains proteins, vitamins and fats (Omega 3 Polyunsaturated Fatty Acids) (PUFAs) among other nutrients (Domingo 2016: 979). Recently, there has been a notable increase in the harvesting of wild stocks of fish and shellfish. Oceans are currently at their maximum sustainable yields to cope with the world’s growing population and the demand for fish and shellfish. Overexploitation and the use of harmful chemicals used in harvesting fish and oil exploitation are some of the core reasons for the global decline of fish. These factors pose a threat to the ecological health of marine resources (Bennette and Dearden 2014: 107) and the economy of low-income countries whose livelihood largely depends on fishing for household and national food security sources (Sowman and Cardoso 2010: 1164). In the research community of Buguma, the decline of the fish population is attributed to the corrosion of pipelines, sabotage and mishandling of oil production operations. The petroleum and gas/oil products from this mismanagement find access directly into the rivers and creeks. The residue from these substances settles on the ocean floor, endangering the ecosystem by killing marine life such as fish and seafood. To this end, food and nutrition insecurity have become evident in the community as livelihoods are dependent on fishing and fish is a primary source of protein. Food insecurity is further aggravated by the high rate of unemployment and low educational attainment. The households are left to apply certain strategies to cope with household food shortfalls. Having to employ certain strategies to cope with food insecurity, negatively affects nutrient adequacy. Thus, inadequate nutrient intake and imbalances have resulted in poor health outcomes and malnutrition. Aim: The study aim was to determine the fishing practices and fish consumption contributing to the nutrient profile, dietary diversity and food security of adult caregivers in a coastal community. Methodology: Two hundred and forty-seven respondents were selected using a multi-stage sampling method. The sample size was calculated using a power calculation indicating that 250 respondents represents a reliable sample out of which 247 respondents completed the research instruments. Sampling procedures were multistage (cluster and random) sampling. The study was descriptive and quantitative in nature. Research tools used to collect data were a sociodemographic questionnaire, a fishing practices questionnaire, a coping strategies questionnaire, a food frequency questionnaire, 3x24-hour dietary recall questionnaires and an anthropometric measurement questionnaire. Food frequency and food security coping strategies questionnaires were compiled through focus group discussions to establish the relevant foods consumed and the respondents were interviewed for the socio-demographic, food frequency, food security coping strategies and fishing practices data. All the respondents were also weighed and measured in order to determine Body Mass Index (BMI), Waist Circumference (WC), Waist to Height Ratio (WHtR) and Blood Pressure (BP) classified in terms of World Health Organization (WHO) reference cut-off points. Socio-demographics, fishing practices, coping strategies and food frequency data were captured on Excel spread sheets and analyzed for descriptive statistics using the Statistical Package for Social Science (SPSS) version 24.0. Data from the 24-hour recall was captured and analyzed for nutrient analysis using the MRC Food Finder® version 3.0 software and comparisons were made to the recommended nutrient standards by the World Health Organization. Results: The mean age group was 31-50 years old. Sixty-one-point one percent (n=151) of the respondents were females and males made up 38.9% (n=96). Most of the fish caught by the respondents was used for consumption (64.0%; n=126) and the rest was used for income generation (36.0%; n=71). The community had on average a secondary school education (55.5%; n=137) and recorded high rates of unemployment (80.2%; n=198) with 62.3% (n=76) actively looking for employment. The respondents indicated that between one person (47.8%; n=118) and two people (46.2%; n=114) contributed to household income. Thirty-three-point two percent (n=82) had an average income of #21,000 to #30,000 (Rand value: R3100-R4000), while 25.5% had a monthly income of #31,000 to #40,000 (Rand value: R4100-R5000), accommodating six persons (42.1%; n=104) and four persons (22.3%; n=55) in the household. Thirty-seven-point seven percent (n=93) and 25.5% (n=63) respectively complained that the household “sometimes” and “always” had insufficient funds to buy food. This had led households to adopt certain coping strategies to combat food shortages. The most frequently used strategies per mean were: “relying on less expensive or preferred foods” (11.47 ±7.949), “limiting portion size” (9.73 ±2.593) and “restricting consumption by adults in order for children to eat” (8.70 ±6.628). The negative effect of applying these coping strategies adversely compromised nutrient adequacy. The 20 top consumed foods showed consumption of more energy dense foods and less fruits and vegetables. The Food Variety Score (FVS) indicated that 51 different individual food items with mean ±SD of 20.83. (±6.546) from all food groups were consumed. Vitamin K, Biotin, pantothenate, calcium, riboflavin and thiamine were below DRIs recommendation cutting across all age groups and genders. Inappropriate imbalances in food intake reflected in BMI, WC and WHtR. The mean BMI for men (25.07kg/m2) and women (27.66kg/m2) fells into the overweight category with a mean average of 26.36kg/m2 for both genders and age groups while only women (95.46cm) were majorly found to be at risk for an elevated WC/ central obesity per mean average. The WHtR at risk factor affected the female gender (88.70%; n=133, 19-50 years and 88.90%; n=18, 51+ years old) compared to their male (44.4%; n=78, 19-50 years and 61.1%; n=18, 51+years) counterparts. Mean high BP for systolic (146.9mmHg) and diastolic (92.2mmHg) BP occurred in women 51+ years old. Conclusion: This research revealed inappropriate eating patterns and increased risk of developing NCDs. The 20 top foods consumed showed consumption of mostly macronutrients and limited consumption of fruits and vegetables across both genders and all age groups. Overweight, at risk for WC and WHtR and High Blood Pressure (HBP) were an indication of the presence of NCDs. Food insecurity resulting from a jeopardized fishing livelihood, high levels of unemployment and low educational attainment were the main causes of a compromised nutritional status in the research community. The introduction of nutrition education and an alternative means of livelihood will assist in addressing the current food and nutrition insecurity.
Food consumption patterns and nutritional risks of women in low and middle income communities in KwaNdengenzi, KwaZulu-Natal
(2018) Gumede, Sthembile; Napier, Carin E.
Food consumption patterns have changed dramatically in the recent times, with traditional diets being replaced by so-called “westernised diets” and leading to nutritional risks such as malnutrition. Contributing factors are urbanisation, climate change, agricultural produce supply (food demand is greater than produce supply) and rising prices, to name but a few. The food security status is also in question as more and more South African households are said to be living in poverty and consequently undernourished even though the country was found to be nutritionally stable compared to previous years. Unemployment and lack of nutrition education also have an impact on communities, in terms of the food being purchased and consumed. The study was conducted to determine the socio-demographic status, food consumption patterns and nutritional risk of a low-income and middle-income community that resides in KwaNdengezi Township in KwaZulu-Natal. A sample of two hundred and fifty eight participants was required for the study. The households in both the north and south of KwaNdengezi Township were randomly selected by using the number of roads listed in the eThekwini municipality map. A sample of 130 households per area was targeted. The required number of households was selected by dividing the number of identified roads resulting in three households targeted in each of the 39 roads in the north section and five households in 26 roads in the south section being targeted. Upon the agreement by participants, the study was conducted where data was collected by means of an interview setting, where participants were interviewed by fieldworkers using pre- designed and tested questionnaires. The follow up was conducted on the days following. The participants answered a three set of questionnaires including, a Socio-demographic Questionnaire (Annexure D), a Food Frequency Questionnaire (Annexure F), 24-Hour Recall questionnaires (Annexure E). The anthropometric measurements were taken in order to determine the BMI status of the participants. The participants were weighed using a Physician Scale for weight, the Stadiometer for height and non- stretchable measuring tape for waist circumference. The north and the south sections of the township were both affected by unemployment, showing worrying rates that also corresponded with other studies illustrating that unemployment is a challenge in South Africa. The unemployment rate in the north section was very high, sitting at 78.5%, compared to the south section at 63.1%; even so both these communities are economically challenged. Food insecurity was more prevalent in the north section as 36.9% of the participants reported always not having enough money to purchase food whilst 0.8% of the participants in the south section reported the same, concluding that the north section is more vulnerable to hunger leading to malnutrition and poverty. The education status of the participants in the north section was a point of concern as only 3.1% of the participants had graduated while almost 29.2% in the south section had graduated; this illustrates a very clear difference, which might also be due to unemployed household caregivers who cannot afford further education. The mean Food Variety Scores (FVS) (±SD) for the north section for all food consumed from the various food groups during seven days was 34.44 (±8.419) and for the south section it was 33.87 (±10.670), indicating a medium food variety score where both sections had a good dietary diversity score ranging from 7-9 food groups, summarising the food group diversity as being in the majority in the north section at 63.85% (n=83) while in south section it was 60.77% (n=79). The results of the energy distribution of macronutrients from the average of the 24-hr recall results when compared to the WHO dietary factor goals showed that the participants’ diet was well balanced in terms of macronutrient intake for both sections while the diet for both sections was lacking in micronutrient intake. The results of the women caregivers for both the north and the south sections illustrated a high consumption of the following foods out of the top twenty foods consumed by the community. The foods mostly consumed included sugar, maize, bread and rice for both the 19-30 and 31- 50 years age groups ranging from 195.15-248.82g for maize, 17.61-18.90g for sugar, 82.73- 108.16g for bread and 127.14-131.69g for rice, meaning that the respondents’ diet was high in calorie intake, hence the doubled DRIs for carbohydrate. Overweight and obesity tests showed alarming results as the majority (56.15%) of women caregivers in the north section were found to be obese while 63.8% of the women in the south section fell into the obesity classification, showing that the women caregivers for both sections are at risk of obesity related illnesses (NCDs). The results for waist circumference showed that 71.53% and 78.46% of the women in the north and south sections respectively were above the waist circumference cut-off point (≥88cm). When the weight-for-height ratio was measured for the whole sample most of the women caregivers (69.23%) were found to be at risk of developing metabolic syndrome. The food consumption patterns illustrated in the study corresponded significantly with the results found. Both the communities consumed a diet high in caloric and fat intake but was low in fruit and vegetable intake. This leads to obesity, resulting in non-communicable diseases as well as micro-deficiencies, leading to malnutrition because of the lack of variety in the food consumed by the population. The lack of food variety is the result of not having enough money for food purchases, explaining the question why the community cannot meet the DRIs as a result of unemployment and poverty as well as a lack of nutrition education. With that said the two communities did not show much of a difference in lifestyle and food choices being made except for the education level that was low for the north section and a bit higher for the south section, as well as livelihoods that also showed that the north section was at a lower economic level than the south section but both the sections were at risk of malnutrition and poverty and needed the same intervention in terms of assistance. In the study it was recommended that policies drafted by the government and stakeholders should be focused and tailored more on women caregiver headed households. More nutrition knowledge should be geared towards educating the most vulnerable and poverty stricken communities. The micronutrient intake must be promoted at lower and middle income communities. The agricultural sector needs to recognise and promote women farmers as well as offer assistance in order to grow their standing as farmers. The government should devise and implement projects that empower women so that they not dependent on their male counterparts.
Food hygiene, safety, handling practices and knowledge of food handlers in a food retail company in Durban, KwaZulu-Natal, South Africa
(2019) Sibisi, Anele Sinethemba; Napier, Carin E.
The purpose of this study was to investigate the food hygiene, food safety, food handling practices and knowledge of Food Handlers in a food retail company in Durban, KwaZulu-Natal, South Africa in order to inform management on the knowledge of the Food Handlers in the company of the standards of food hygiene, food safety, and food handling practices. The objective was to determine and describe the knowledge of food hygiene and safety versus the standard of the observed food hygiene, safety and handling practices demonstrated by the Food Handlers in the particular establishments. Literature suggests that there is a direct correlation between knowledge and performance with regard to the food hygiene and safety standards that would exist in an establishment (Seaman 2010). This study attempted to draw a correlation between the managers/supervisors (Mngrs/Sups) knowledge and that of the Food Handlers (FHs) as it was of particular interest, in order to verify the assumptions made by other researchers with regard to management/supervisory knowledge being linked to the level of food knowledge and practices demonstrated by the Food Handlers (Medeiros, Cavalli, Salay, and Proenca 2011). The research was conducted in 20 food service establishments that belonged to the same food retail company in Durban, KwaZulu-Natal. This food retail company has about 150 stores which practice voluntary trading. The company has a very solid food safety policy which is made available to the owners of each establishment to implement and maintain. Quarterly food safety audits by an external company are carried out at each establishment and the results are shared with the owners in order to close any gaps that may exist. This research aims to provide data that will report on the food safety standards in each establishment as assumed by the company to be practised. The sample was randomly selected (all the names of the stores were put into a container and randomly selected) based on the establishment category i.e. mini market, super market and hyper store. Ethical approval was granted by the Institutional Research Ethics Committee at Durban University of Technology. The total sample for the study was 250 which was made up of 234 Food Handlers and 16 managers/supervisors. Information letters and consent forms were presented to and signed by the participants before data collection commenced. The study design was observational and descriptive by nature. To determine the food hygiene, food safety, food handling practices and knowledge of Food Handlers, two questionnaires were administered and an observation checklist was administered. All data collection was quantitative and all participation was voluntary. A permission letter was obtained from the company which was used to grant the researcher entry into the establishments but access was dependent on permission being given by the owners of the selected establishments. Data obtained from this questionnaire was captured on a Microsoft Excel® Spreadsheet and analysed for descriptive statistics using the Statistical Package for the Social Sciences (SPSS), version 24. The majority of the workforce was made up of females at both management and food handler level (75.0%; n=12 and 74.8%; n=175 respectively). The study group was predominately aged 30 years and older with the majority having grade 12 as the highest level of education. Noticeably, not all of the managers and FHs were trained upon appointment although the company has a solid food safety induction resource programme that is made available and distributed to each establishment. The food safety training module focuses on all aspects of food safety but since not all the respondents were trained on all the 12 modules, they displayed greater knowledge in selected areas and less in others; for instance, greater knowledge was shared about personal hygiene compared to record keeping, temperature recording and pest control, which are critical elements in ensuring food safety. To support this finding, unexpectedly 25.0% (n=4) of Mngrs/Sups and 47.0% (n=110) of the FHs stated that according to their knowledge thawing frozen food on the counter at room temperature was acceptable. This demonstrated that almost half of the FHs did not know that it is important to prevent bacteria present in food from multiplying in order to eliminate food poisoning. Additionally, the practice of thawing/defrosting food at room temperature was observed at most of the establishments but mostly at the Hyper stores. Furthermore, the vast majority of FHs knew that food should not be handled when they are suffering from any type of health problem, but 7.3% (n=17) stated that when they are suffering from the flu, and are coughing and sneezing, they are still permitted to handle food which assumes that it does not pose a risk to food safety whereas all the Mngrs/Sups knew that illness should not be permitted in the food production areas. Some FHs even stated that they would come to work sick otherwise they would not be paid. Almost all (n=15; 93.8%) of the Mngrs/Sups correctly stated that wiping cloths spread microorganisms but not all of the Mngrs/Sups knew that wiping cloths should be placed in a sanitizer bucket in-between use. This indicates a lack of knowledge with regard to food safety hazard preventative measures. Some of the FHs did not know that not all chemical cleaning products are graded as being effective in a food production/preparation environment and that general cleaning removes dirt only while sanitizing surfaces also kills bacteria. More than half of the FHs incorrectly stated that it was acceptable to leave mops and brushes in a bucket of dirty water in-between use which was an unacceptable practice prevalent in most of the establishments. The vast majority (93.8%; n=15 Mngrs/Sups, 93.2%; n=218 FHs) of the respondents agreed that food that has reached its expiry date should be thrown away but the researcher found during the observations that some of the establishments had expired stock that was being used in food preparation, and this was mostly evident at the Hyper stores (80.0%; n=4); however, at the Mini stores the expired stock was still on the shelves for sale. A shortage of utilities, resources and facilities in the various establishments was highlighted as a stumbling block to obtaining and achieving the desired food safety standards. Some establishments were under new ownership and were still establishing food safety structures. The outcomes of the study will be made available to the management of the food retail stores in the hope that the standards of food safety in each establishment will be improved as an unfortunate food incident will tarnish the brand image of the organization and not just the particular establishment.
Food safety practices, nutrition knowledge and menu adequacy at non-registered Early Childhood Development (ECD) centres in the Ntuzuma Area, Durban, South Africa
(2023-05) Shabangu, Gugu Bongiwe; Grobbelaar, Heleen; Napier, Carin; Ijabadeniyi, Oluwatosin Ademola
Globally, millions of children are deprived of their right to good nutrition which contributes to child development and nurturing while eliminating preventable diseases that could affect them at their early age. According to the World Health Organisation (WHO), food safety has become a health priority over the years with more than 95% of deaths reported globally due to diarrhoea and dehydration and 40% of these being young children. Food safety is the responsibility of every person who is involved in food handling. In general, food handlers’ mistakes include serving contaminated food, inadequate cooking, heating or reheating of food and allowing the consumption of food from unsafe sources. Children spend more than 50% of their day at an Early Childhood Development (ECD) centre therefore centres need to provide adequate meals and snacks in order to provide for the basic nutritional needs of these children. Nutrition remains an essential element of a child’s health care and nutrients are important for optimum growth, which is why regular small healthy meals for young children should include fruit and vegetables, whole grain and cereals, meat and meat alternatives (fish, legumes). The aim of this study was to investigate the food safety and hygiene practices, and evaluate the current nutrition knowledge of food handlers and also assess the nutritional adequacy of the menus at nonregistered ECD centres. This study also aimed to observe the food handling and hygiene practices of the food handlers and also determine the menu adequacy of meals served to the young children in these non-registered ECD centres. The designing of the research is one of the important steps in conducting a research as it helps structure research questions and objectives that have been outlined to provide a solution. This cross sectional study was of a quantitative nature and data was collected through structured research measuring tools that have been tested for their validity and reliability, and ensuring accuracy in measurements. A list of non-registered ECD centres (n=10) based in the Ntuzuma area was provided to the researcher by the Department of Social Development’s (DSD) Durban office. It must be stated that this list consisted of ECD centres that were not registered with DSD at the time of the study but were in the process of complying with the regulations and requirements stated by DSD, to assist in the sampling process. All ten of the centres were approached by the researcher and they all agreed to participate. Questionnaires and the observation checklist were then piloted in a sample group to establish suitability and adapted if necessary in one ECD centre while the remaining ECD centres formed part of the study (n=9). Eleven participants in total, two of whom were food handlers who assisted the managers when they were not available and nine who were both managers and food handlers formed part of the study. The researcher also conducted a plate waste study to determine the consumption patterns during meal times. Food finder version 2019 software was used to analyse the menu adequacy in each ECD centre by comparing it to the DRIs for children younger than five years old. Data collected from this study showed that food handlers were more knowledgeable on certain aspects of food safety as the majority of the food handlers knew that raw and cooked food needed to be placed separately during storage to prevent cross contamination. The vast majority of the centres had adequate space and utensils for cooking but insufficient chopping boards. Furthermore, simple hygiene practices such as washing of hands after a visit to the toilet and before food preparation were demonstrated by most of the food handlers. However, there was no antibacterial soap available for hand washing and no designated hand washing stations. Knowledge on temperature control was poorly demonstrated as all cooked foods should be kept very hot before serving; however, the food handlers kept their food warm by leaving it in pots on the stove with the lid tightly secured during the holding stage. The data gathered from this study was that food handlers at all the non-registered ECD centres needed to attend intensive formal training on food safety and hygiene practices on all the different aspects of food safety Nutrition knowledge questionnaire showed that majority of the FHs were able to correctly answer most of the questions relating to the South African Food Based Dietary Guidelines. However, it was disappointing that most of the food handlers were not aware that an average of 8 glasses of water a day are recommended to be drunk. The dietary analysis indicated that there was a low consumption of fruits and vegetables and dairy products as most meals lacked essential macro and micronutrients, contributing to the poor nutritional status of the young children. The microbial analysis revealed that the occurrence of Staphylococcus aureus and Escherichia coli was visible on the hands of the food handlers, the chopping boards and the preparation surface areas in each centre before washing but no growth was observed after washing, indicating that the cleaning process was effective. The overall observation assessment suggested that food safety compliance was not implemented. This indicates that thorough food safety and hygiene training is urgently needed. This study aimed to determine the food safety, hygiene practices and nutrition knowledge of all the food handlers, while analysing and assessing the nutrition adequacy of the menus offered to the children in these non-registered ECD centres, and lastly, to observe the food safety practices of food handlers and analyse the food workspaces for bacterial count. More research at non-registered ECD centres in other provinces is crucial in order to compare the results to the results obtained in this study. It is also recommended that other government stakeholders such as the Department of Social Development and the Department of Health be engaged in order to supplement existing knowledge and implement further practical improvements.