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Subject: search.filters.subject.Asparagaceae

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    Anticancer activity of silver nanoparticles embedded in porous starch as a potential delivery system
    (2024-05) Mohan, Naaznee; Mellem, John Jason
    Silver nanoparticles have been proven to have anticancer abilities but they have been known to agglomerate and become toxic. Therefore, various studies have been conducted to explore ways of preventing aggregation using biopolymers such as starch. This study makes use of Lablab purpureus (hyacinth bean) porous starch to biosynthesize and encapsulate silver nanoparticles and then test its anticancer potential. Porous starches were produced from hyacinth bean using three different techniques. These were compared against the native starch with silver nanoparticles, then synthesized and encapsulated using the porous starch. In comparison to the native starch, the porous starches made through solvent exchange and enzyme hydrolysis had similar outcomes with granules exhibiting pores, as shown by the structural and chemical characteristics. The lack of pasting properties and extremely distinct chemical and structural graphs of the porous starch, produced by freeze-thaw procedures, may be related to the presence of mercaptosuccinic acid. It was decided to employ porous starch made by solvent-exchange (SE) for the manufacture of silver nanoparticles as it contained resistant starch. Nanoparticles were produced using the porous starch from solvent-exchange, characterised and tested for their anticancer potential. Silver nanoparticles were indicative of a colour change from clear to brown, as well as, the characteristic peak at 425 nm for silver nanoparticle formation. Silver nanoparticles were implanted into porous starch at a size of around 50 nm, as further evidenced by the particle size distribution and TEM images of spherical granules with dark spots within. The zeta potential for the silver nanoparticles was -34 mV, thereby indicating that aggregation was minimized and particles were stable. The nanoparticles demonstrated less cytotoxicity in the human colon (CACO) and cervical (HELA) cancer cell lines, but more inhibition in the human breast (MCF-7) cancer cell line than the positive control camptothecin. The human muscle (C2C12), normal cell line's capacity to sustain cell viability for silver nanoparticles demonstrated that AgNP were not toxic. However, to maximize the potential of the silver nanoparticles implanted in porous starch, more research is necessary.
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    Effects of processing on the characteristics of flour and protein isolates produced from Lablab purpureus
    (2020) Naiker, Tremayne Sheldon; Mellem, John Jason; Amonsou, Eric Oscar; Baijnath, Himansu
    The utilization of legumes by food industries has grown considerably in intermediate forms other than whole grains. Thus, continuous work is focused on modifying legume-based raw materials for improving its techno-functional properties whilst preserving its nutritive value. The study conducted was aimed at analyzing the effects of processing treatments on the characteristics of flour and protein isolates produced from Lablab purpureus (L.) Sweet (hyacinth bean). Flour was produced from legume grains subjected to steaming (S+A) and dehydration (S+A+D) treatments, following soaking (S). Protein isolates were produced from respective flour fractions using isoelectric precipitation. Samples produced from steaming and dehydration was found useful for potential application as functional food ingredients for nutritional intervention. The respective flour samples contained improved resistant starch (23.44 g/100 g dry starch) content. Swelling and solubility indices were found to be greater at lower temperatures mainly attributed to the pre-gelatinization of starch granules. Thus, they may be potentially suitable for ingredient application in texture modified foods. Protein isolates produced displayed traits typical of high-quality proteins and demonstrated exceptional functionality. The rapid increase in predicted biological values observed suggested improved protein digestibility potential. Samples contained significant concentrations of branched chain and aromatic amino acids highlighting potential health benefits. Protein nanoparticles were produced using Ca2+-induced aggregation (0.00-6.50 mM) from hyacinth bean protein isolate (2% m/v, pH 7). This was to examine its potential for development as food- grade Pickering emulsion stabilizers. Protein solutions containing high Ca2+ concentrations resulted in higher dynamic viscosities (mPa.s). Protein nanoparticles (~172.38 nm) were formed at 3.50 mM Ca2+. The z-average diameter of aggregates was dependent on Ca2+ concentration. Results satisfied certain criteria for nanoparticles to potentially function as Pickering stabilizers. However, nanoparticles were susceptible to 4 M Urea and emulsion creaming became more apparent as storage progressed. The study conducted provides valuable information on how processing could be useful for obtaining value-added legume grain ingredients for potential food applications. Such approach could diversify the use of hyacinth bean and help improve the competitiveness of the legume grain sector.