Antioxidant Activity and Lipase Inhibitory Activity in Rice Miso Supplementary with Black Soybean, Buckwheat and Adzuki Bean

Abstract

In the present study, we manufactured rice miso supplementary with black soybean, buckwheat and adzuki bean. We analyzed DPPH radical scavenging activity, melanoidin, peptide, reducing sugar content, and lipase inhibitory activity in various rice miso products at different fermentation periods (3, 6, 24, 36 months), respectively. DPPH radical scavenging activity, melanoidin content and lipase inhibitory activity in various rice miso products increased with prolonging the fermentation period. We found positive relationships between melanoidin content and DPPH radical scavenging activity, and lipase inhibitory activity. The correlation coefficients were more than 0.75, respectively. Rice miso supplementary with black soybean (RM-BS), rice miso supplementary with buckwheat (RM-BW) and rice miso supplementary with adzuki bean (RM-AB) exhibited significant higher DPPH radical scavenging activity, melanoidin and lipase inhibitory activity than RM (rice miso; control), respectively. We considered that due to prolonging the fermentation period, more and more starch and protein contained in RM-BS, RM-BW and RM-AB were decomposed into reducing sugar, peptide and amino acid, than those of RM. So thus rice miso supplementary with black soybean, buckwheat and adzuki bean could improve DPPH radical scavenging activity and lipase inhibitory activity of traditional rice miso products, which may be because of plenty of melanoidin was produced through the amino acid-glucose reactions. These results would utilize in the research on development functionality of rice miso products.