Retention levels of vegetable extractable beta-carotene preserved in virgin coconut oil and unadulterated honey

Dark green leafy vegetables such as Amaranthus spp. are known to be good sources of beta-carotene, a pro-vitamin A carotenoid with highly potent antioxidant property. As an antioxidant, beta-carotene scavenges for electron and thus terminates chain reactions, prevents recurrence and formation of unstable oxygen which otherwise initiate a chain reaction leading to such cases as cancer. While beta-carotene is supplied from consuming vegetables to provide vitamin A, it is also given as a supplement in cases of deficiency. However, it is highly degraded in the presence of light, heat, and oxygen posing a challenge to the methods of its preservation. Coconut oil and honey are popularly consumed in many countries facing vitamin A deficiency as good antioxidants and yet their role in preservation is largely unknown. The study reports the retention of beta-carotene extracted from Amaranthus spp. and separately preserved in virgin coconut oil (VCO) and unadulterated honey for up to six months. HPLC and DPPH assay were used to determine beta-carotene and antioxidant activity respectively. Virgin coconut oil and honey had significantly different (p<0.001) antioxidant activities of 65.12±0.70 and 81.51±1.39 % radical scavenging activity respectively that compared well with those of BHT and ascorbic acid. The concentration of beta-carotene preserved in VCO and unadulterated honey degraded by 90%, though the final retention provided higher than the recommended daily allowance of retinol (0.216±0.001 and 0.312±0.003 retinol activity equivalent respectively) when 100 mg is consumed. Virgin coconut oil and unadulterated honey can preserve beta-carotene if high amounts are used

Fabrication of Nanostructured Polyamic Acid Membranes for Antimicrobially Enhanced Water Purification

Water scarcity and quality challenges facing the world can be alleviated by Point-of-Use filtration devices (POU). The use of filtration membranes in POU devices has been limited largely because of membrane fouling, which occurs when suspended solids, microbes, and organic materials are deposited on the surface of filtration membranes significantly decreasing the membrane lifespan, thereby increasing operation costs. There is need therefore to develop filtration membranes that are devoid of these challenges. In this work, nanotechnology was used to fabricate nanostructured polyamic acid (nPAA) membranes, which can be used for microbial decontamination of water. The PAA was used as support and reducing agent to introduce silver nanoparticles (AgNPs) and gold nanoparticles (AuNPs) with antimicrobial properties. The nPAA membranes were fabricated via thermal and wet phase inversion technique and then tested against Escherichia coli and Staphylococcus aureus following standard tests. The resulting nanoparticles exhibited excellent dispersibility and stability as indicated by the color change of the solution and increments of optical density at 415 nm for AgNPs and 520 nm for AuNPs. The wet phase inversion process used produced highly porous, strong, and flexible nPAA membranes, which showed well-dispersed spherical AuNPs and AgNPs whose rough average size was found to be 35 nm and 25 nm, respectively. The AgNPs demonstrated inhibition for both gram positive E. coli and gram negative S. aureus, with a better inhibitory activity against S. aureus. A synergistic enhancement of AgNPs antimicrobial activity upon AuNPs addition was demonstrated. The nPAA membranes can thus be used to remove microbials from water and can hence be used in water purification