Effects of Roasting on the Phytochemical Contents and Antioxidant Activities of Korean Soybean (Glycine max L. Merrill) Cultivars

Abstract

Antioxidant activities of roasted soybeans from Daewon, Daepung, Neulchan, and Taekwang cultivars were evaluated using DPPH and ABTS radical scavenging activities and FRAP assays. Roasted soybeans exhibited significantly (p < 0.05) higher antioxidant activities than unroasted soybeans. Daepung soybeans roasted at 200A degrees C for 15 min exhibited higher antioxidant activities than other cultivars and soybeans roasted under other conditions. Contents of antioxidant compounds, including isoflavone aglycones, glycosides, and phenolic acids, increased after roasting, whereas the content of isoflavone malonlyglycosides was decreased in the roasted soybeans. Moreover, total phenolic and flavonoid contents and isoflavone aglycone, glycoside, and phenolic acid contents were increased, leading to a general increase in antioxidant activities due to roasting.