Abstract:

This study aimed to explore the in vitro antioxidant activities of total flavonoids and total polyphenols from
tartary buckwheat natto, made from mixtures of soybeans and tartary buckwheat fermented with Bacillus subtilis natto. The
scavenging rates against 1,1-diphenyl-2-picrylhydrazyl radical (DPPH), 2,2’-azinobis(3-ethylbenzothi azoline-6-sulfonic
acid) ammonium salt (ABTS), hydroxyl and superoxide anion free radicals, and reducing power were investigated and
compared with those of yellow soybean paste and sweet soybean paste. The results showed that tartary buckwheat natto
exhibited the highest scavenging activities on DPPH, ABTS, hydroryl and superoxide anion free radicals despite having
slightly weaker Fe3+ reducing activity than sweet soybean paste. Our results also showed a highly significant correlation
between antioxidant capacity and either total flavonoids or total polyphenols (P ＜ 0.01) for all three investigated samples.

Key words: tartary buckwheat natto, total flavonoids, total polyphenols, antioxidant activity