Soy Milk By-product: Its Composition and Utilisation

Soy milk by-product is the insoluble fraction of the soybean cotyledon after the production of soy milk and is generally considered a waste material. With increased production of alternative milks, this by-product has caused environmental and financial issues for manufacturers. This residue contains high levels of nutrient such as protein, fibre, and lipids, micronutrients and phytochemicals. Composition has been found to be influenced by soybean varieties, processing conditions and post-production treatments. As this by-product has a high moisture content, nutrient and bioactive components can be quickly degraded due to oxidation, enzymic and microbial activities. Post-production treatments have been applied, to minimise degradation and spoilage. Being a rich source of nutrient and bioactive components, there is potential for use as a food ingredient. This review aims to outline some current manufacturing process, how this waste is generated and treated, highlight nutritional composition, review the current application of soy milk by-product and discuss potential future study trends.