Effect of roasting on phytochemical properties of Thai soybeans.
Soybeans are a rich source of protein and widely cultivated in Thailand, and they have various bioactive ingredients, which have antioxidant and anticancer activates. This investigation revealed the phytochemical properties of three Thai roasted soybeans (RSB), which were roasted at 230oC for 12, 15 and 18 min, including the total phenol content (TPC), total flavonoid content (TFC), 2,2-diphenyl-1-picrylhydrazyl (DPPH), ferric reducing antioxidant potential (FRAP) and βcarotene bleaching activity. Additionally, we measured the mutagenicity by the Ames test and anti-carcinogenic properties in the MCF-7 cell line. The RSB showed significantly higher antioxidant activity than raw soybean in TPC, TFC and all antioxidant assays. In particular, the RSB of SJ5 at 230oC for 15 min showed the highest antioxidant activity. Moreover, almost all of the RSBs did not have mutagenicity properties, in addition, no anticancer effects of RSBs were found. Therefore, the phytochemical properties of RSB depended upon the type of soybean, and the antioxidant activity can be maximized by roasting. This results shown beneficiary of increasing antioxidant activity of RSB with safe for nonmutagenicity approved.