Valorization of seed and kernel marcs and evaluation of their antioxidant potential.

The processing and consumption of mango (Mangifera indica) generate a sizeable amount of kernel waste with enormous and largely unexplored potential, while by-products from njangsa (Ricinodendron heudelotii) seed and bush mango (Irvingia gabonensis) kernel oil extraction are often discarded. This study aims to repurpose these kernels and seed wastes into added/high-value products and evaluate the ethanolic and methanolic extracts of their pressed marcs for polyphenolic content and potential antioxidant activity. The total phenolic content (TPC) and total flavonoid content (TFC) in the marc extracts ranged between 47.87 and 376.0 mg GAE/g and 4.85 and 13.70 mg Rutin/g, respectively. Both mango kernel marc extracts showed higher potent reducing power, ABTS+ radical and DPPH radical scavenging activities with half effective concentration (EC50) values (0.20-0.22 mg/mL) comparable to the reference compound; ascorbic acid (0.20 mg/mL). The TPC and TFC of the marc extracts generally strongly correlated with antioxidant activity. Relatively higher contents of xanthophyll and ß-carotene were detected in bush mango kernel methanolic extract than in the other extracts. Extraction solvent affected the composition and content of bioactives in pressed marcs of njangsa seed and mango kernel.

Lipase-catalysed synthesis of palm oil-omega-3 structured lipids.

In this work, Candida antarctica lipase A was applied to selectively remove saturated fatty acids from palm oil to prepare palm oil acylglycerol concentrate (POAC), where palmitic acid decreased from 40.0 to 28.7% and oleic acid increased from 40.0 to 50.5% after 3 h of hydrolysis. Lipozyme RMIM from Rhizomucor miehei was then used to incorporate either alpha linolenic acid (ALA) or eicosapentaenoic acid (EPA) into the resulting POAC. Optimum omega-3 incorporation was achieved when POAC to omega-3 ratio was 6 : 3, reaction temperature was 40 °C and reaction time was 18 h. Under these conditions, the ALA content in the separated ALA incorporated structured lipid (POAC-ALA) was 27.1%, and the EPA content in the EPA incorporated structured lipids (POAC-EPA) was 30.9%. The formed structured lipids had lower levels of saturated fatty acids, and significantly lower melting points, in both cases below 8 °C. The enzymatic process developed produces new structured lipids, with lower saturated fat and higher omega-3, with potential as a healthy palm oil derived lipid ingredient.

Influence of conventional and recent extraction technologies on physicochemical properties of bioactive macromolecules from natural sources: A review.

The incorporation of bioactive macromolecules from natural sources into marketable functional foods and nutraceuticals is of major significance to the agri-food sector. Interest in this area of research stems from the application of purified bioactive macromolecules in enhancing food quality and as an alternative to some pharmaceutical drugs for delivery of potential health benefits, with less associated adverse effects. To obtain bioactive macromolecules of high quality, appropriate use of extraction techniques and its influence on sensory and physicochemical properties is paramount. With the advent of technology-aided processes, there has been remarkable improvement in the extraction efficiency of these bioactive agents. An overview of the influence of these new techniques on extraction efficiency and physicochemical properties of proteins, lipids and fibers, which this detailed review provides, will prove to be a valuable resource to food industries aiming to maximize production of bioactive macromolecules from natural sources as well as the scientific community.