Valorizing okara waste into nutritionally rich polysaccharide/protein-extracts for co-encapsulation of β-carotene and ferrous sulphate as a potential approach to tackle micronutrient malnutrition

Colossal amounts of food waste are generated and discarded daily at the expense of financial resources and at a detriment to the environment. One such food waste, okara – a soybean by-product, is valorized in this study by upcycling it into nutritional extracts for micronutrients encapsulation. Micronutrient malnutrition, particularly in the developing world, is a major public health challenge. Herein, okara extracts were obtained through a low-cost extraction process and was subsequently developed as an encapsulant material for micronutrients β-carotene, and ferrous sulphate encapsulation, using zein as an excipient. Spray-drying, as a scalable technique, was employed to produce various formulations which were assessed for release profiles, shelf-life, β-carotene antioxidant activity and cell cytotoxicity. Finally, an optimized dual-micronutrient formulation displayed a sequential release with ferrous sulphate releasing in simulated gastric fluid, and β-carotene releasing predominantly in simulated intestinal fluid. This sequential release profile favors the absorption of both the micronutrients and could potentially enhance their bioavailability.