Impact of germination on the chemical components and bioactive properties of adlay (Coix lachryma-jobi L.) water extract

In recent years, adlay water extract and related products have been widely consumed. This study investigated the chemical components and bioactive properties of adlay water extract at different germination stages. Glucose and maltose were significantly increased, whereas fructose was slightly decreased after germination. The contents of vitamins C and B-1 in the water extract increased 1.61- and 2.68-fold, respectively. The amounts of peptides, especially those with a molecular weight under 3000Da, were significantly increased after germination. During germination, the level of total free amino acids rose from 54.09 to 128.22gmL(-1), and the percentage of essential amino acids was elevated from 21.63% to 42.13%. Germination also substantially augmented the total phenolic content and antioxidant activity of the water extract. Moreover, the germinated adlay water extract showed higher inhibitory activity on angiotensin-converting enzyme (ACE), xanthine oxidase and tyrosinase than the water extract of nongerminated adlay. These findings revealed that germination might be a potential way to improve the nutritional value and bioactive properties of adlay water extract.