Optimizing aquasoya protein: Insights of various pre-treatments for enhancing the upcycling potential from small black bean by-product

To minimize resource waste and promote recycling, it is essential to recover nutritional components from by-products. This study aimed to optimize of Aquasoya protein (AS-P) recovery from small black bean by-products, focusing on the effects of pH adjustments, sonication, and fractionation on protein yield, solubility, and structural integrity. Alkaline treatment at pH 8.5 significantly enhanced AS-P recovery yield (77.60 %) and protein concentration (421.16 μg/mL), attributed to the increased solubility and effective removal of non-protein components. Sonication for 10 min exhibited the highest protein solubility (88.69 %) post-fractionation, indicating reduced protein aggregation. Fractionation was crucial in minimizing browning reactions and enhancing protein purity by eliminating oligosaccharides and impurities. SDS-PAGE analysis revealed distinct protein bands from alkaline treatment, while sonication resulted in lipoxygenase (LOX) protein degradation. Principal Component Analysis (PCA) emphasized that fractionation notably enhances the stability and quality of AS-P, making it as a viable ingredient for food applications.