Changes in the Bioactive Content and Antioxidant Activity of Natto during Fermentation and In Vitro Digestion
Article
Figures
Metrics
Preview PDF
Reference
Related
Cited by
Materials
Abstract:
Changes in the contents of active substances (including total phenols and isoflavones) during the fermentation of natto with Bacillus subtilis natto were studied. Levels of total phenols and isoflavones during the digestive process were measured in an in vitro digestion experiment, and the pattern of changes in antioxidant activity was studied. The results showed that after bacterial fermentation at high temperature, total phenolic content and isoflavone content in the after-ripening soybeans (24 h) were increased by 65.12% and decreased by 63.28%, respectively, compared with those of dry soybeans. The in vitro digestion experiments were conducted on the natto samples at different fermentation stages, and the release rate of total phenolics was 70.64% while the residual rate of isoflavones was 21.79%. Hydroxyl radical (?OH), 2,2-diphenyl-1-picrylhydrazyl (DPPH?), and 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid (ABTS) scavenging abilities and oxygen radical absorbance capacity (ORAC) were used to determine antioxidant activity. After in vitro digestion, the scavenging ability of DPPH radicals was decreased in natto at different fermentation stages, and both ABTS scavenging ability and ORAC values were elevated. During the gastric digestion simulation stage, the scavenging ability of ABST radicals and the ORAC value in the after-ripening soybeans (24 h) were 1.80 and 2.22 times those of dry beans. During the intestinal digestion simulation stage, the scavenging ability of ABST radicals and the ORAC value of the after-ripening soybeans were 1.70 and 1.41 times those of dry beans. In summary, the antioxidant activity of the natto was increased after fermentation, and the natto from the gastric digestion stage showed higher antioxidant activity during the in vitro digestion process.
