Red beans exhibit many biofunctions, including the stimulation of intestinal motility, improvement of
anemia and elimination of edema. This study was conducted to evaluate the functional properties of
microbially fermented red beans produced under different fermentation conditions and to establish the
optimum fermentation conditions for the production of fermented red beans with multiple biofunctions.
The optimum fermentation conditions were the fermentation of red beans by a co-culture of Bacillus
subtilis and Lactobacillus bulgaricus in the presence of 1% glucose, incubated at 30 C for 120 h and stirred
every 24 h. Compared with unfermented red beans, red beans fermented under the optimum conditions
contained a higher concentration of antioxidant substances, including total phenolics, anthocyanin,
flavonoids and vitamins C and E. The results of tests for DPPH-radical scavenging, ferrous ion chelation
and reducing power implied a high antioxidant content. Fermented red beans exhibited nattokinase
activity and contained a significant amount of potential probiotics.