Optimization of Ethanol-Water Solvent System for Total Flavonoid Extraction from Okara

Abstract

Okara, an agro-industrial by product of soybean processing, is a potential source of flavonoids, particularly isoflavones. However, its large scale production often exceeds current utilization, resulting in its underexploitation. This study investigates the effect of ethanol-water solvent ratios on the total flavonoid content of dried okara powder and includes physicochemical characterization of the raw material. Extraction was carried out by maceration using ethanol-water mixtures (v/v) of 1:2 and 2:1. The total flavonoid content was 676.88 ± 15.66 µg/g dry weight for the 1:2 solvent system and 137.87 ± 0.53 µg/g dry weight for the 2:1 solvent system. These findings demonstrate that increasing the proportion of water in the solvent system enhances the extraction efficiency of flavonoids from okara.