Okara extract as a potential platform for micronutrients encapsulation in food fortification

Abstract

Micronutrients malnutrition is one of the major public health challenges in the world, particularly in developing countries. Various strategies have been established to address this problem. Food fortification is one of the most effective, cost-efficient, and sustainable strategies, which involves the addition of micronutrients to common staple foods to maintain or improve the quality of one’s diet. However, micronutrients are not stable by themselves and encapsulation with a stable and digestible material is needed. One potential materials for encapsulation is Okara, a nutritionally rich by-product generated during tofu and soymilk production processes. Unlike other alternatives—such as hydrogenated oils, alginate, tapioca, etc.—that have been previously investigated for micronutrients encapsulation, okara usage for micronutrients encapsulation is a novel avenue which remains unexplored. Thus, the objective of this study was to investigate an effective extraction method for okara processing and develop an encapsulation system for β-carotene. The efficacy of extraction process was investigated in varying acidic/alkaline conditions, followed by two different drying methods; freeze-drying and spray-drying. The extracts were tested with FTIR, TGA, DSC, and SEM analysis for material characterization and the extracts were then used to encapsulate β-carotene. A highly acidic condition (pH 2) was observed to be the most effective for the okara-polysaccharide extraction.