Total Phenolic and Flavonoid Contents of Soybean Fermentation by <i>Bacillus subtilis</i> SB-MYP-1

Abstract

Various fermented soybean, as functional food products, are widely available in worldwide. Total phenolic and flavonoids contents containing in soybean are the potentially health benefit components. In addition, soybean fermentation could enhance the amount of these components. Therefore this study is focused on comparison of total phenolic and flavonoid contents between fermented soybean processed by the application ofBacillus subtilis SB-MYP-1.Soybean and soybean crude extracts that prepared by water and ethanol solvent. The total phenolic and flavonoid contents of fermented soybean crude extracts (FSB) were found significantly higher (p< 0.05) than soybean crude extract (SB). Ethanol FSB showed the highest total phenolic and flavonoid contents at 35.02±0.60 mg gallic acid equivalent/g extract and 14.02±0.66 mg catechin equivalent/g extract while as ethanol SB showed total phenolic and flavonoid contents at 16.94 ± 0.77 mg gallic acid equivalent/g extract and 8.77±0.21 mg catechin equivalent/g extract, respectively. In the same way, water FSB showed the highest total phenolic and flavonoid contents at 29.02 ± 1.37 mg gallic acid equivalent/g extract and 7.02 ± 0.61 mg catechin equivalent/g extract while as water SB showed total phenolic and flavonoid contents at 14.43 ± 0.77 mg gallic acid equivalent/g extract and 5.37 ± 0.24 mg catechin equivalent/g extract, respectively. In conclusion, the fermentation process could enhance total phenolic and flavonoid contents in soybean including ethanol extraction gave higher total phenolic and flavonoid contents in crude extracts. Furthermore, functional properties of both water and ethanol crude soybean extracts should be studied in vitro for beneficial in application in food products and dietary supplement in the near future.