Extracts of wheat bran and barley husk with solvents of different polarity were analyzed to determine the concentration of bioactive compounds (phytic acid, saponins, flavonoids, total phenolic compounds and phenolic profile) and their antioxidant activity by DPPH and ABTS assays. The results showed that the phytic acid concentration in wheat bran was higher than the phytic acid concentration in barley husk. The concentration of saponins was inverse with higher concentrations in barley husk than wheat bran. The solvents with the highest extraction of phytochemicals were 80% ethanol in wheat bran and 50% acetone in barley husk. The chromatograph profile showed that wheat bran presented a greater concentration of caffeic acid and barley husk contained kampferol. The properties of extraction solvents significantly affected the concentration of flavonoids, phenolic compounds, and antioxidant activity. The addition of water to the solvents increased the extraction efficiency of bioactive compounds and antioxidant activity. The results for barley husk are among the first reported because there are few studies on this cereal.

The objective of this research was to evaluate the effect of germination on the content of phenolic compounds, isoflavones and antioxidant activity of soybean extracts obtained from ungerminated soybeans and those germinated for 2 and 6 days. After 6 days of germination, the content of most phenolics, including isoflavones, significantly increased compared with that of samples from ungerminated soybeans and soybeans germinated for 2 days. The free phenolic compounds, benzoic and vanillic acids, decreased during the germination process. The antioxidant activity of the soybeans increased with germination time, and a high correlation was observed among total phenolic contents (TPCs), Trolox equivalent antioxidant activity (TEAC) and ferric reducing antioxidant power (FRAP). Isoflavones also showed high correlations with TEAC and FRAP assays, and only glycitin showed relatively low correlations. The process of germination allowed for increases in bioactive phenolic compounds and isoflavone aglycon. These effects enhanced the functional properties of the soybean.