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.