Changes in antioxidants and nutritional properties during germination of soybean

Soybeans are a valuable source of nutrients and bioactive compounds. However, their nutritional quality can be limited by the presence of antinutrients, such as phytic acid and trypsin inhibitors. Germination is a natural process that can enhance the nutritional value of legumes by reducing antinutrients and increasing the bioavailability of nutrients. The objective of this study was to evaluate the effect of soaking and germination on the antioxidant and nutritional attributes of soybean. Results showed that the germination process led to a significant increase (p ≤ 0.05) in the content of phenolic, flavonoids, and antioxidat activity (%) compounds following the 72-hour germination compared to samples from ungerminated soybeans. Strong correlations were concluded between antioxidant activity and total phenolic (R² 0.92), flavonoids (R² 0.82), and ascorbic acid (R² 0.99). The germination process also enhanced proteases activities, lipase activity, and protein digestibility. Concurrently, there was a significant reduction in phytic acid from 99.20 ± 2.56 to 73.39 ± 0.85, mg/100 g as well as trypsin inhibitors from 5.73 ± 0.116 to 2.91 ± 0.126 mg/g. Germination led to these alterations contributed to an enhancement in the antioxidant and nutritional characteristics of soybean.