Abstract:In this paper, Streptococcus thermophilus, Lactobacillus bulgaricus and mixed bacteria were used to ferment the mixture of whey protein and blueberry juice. The effects fermented time of initial, 24 h, 36 h and 48 h on the antioxidant properties of whey protein, blueberry juice through single and mixed fermentation were investigated. The results showed that the reduction capacity of the mixed whey protein and blueberry system fermented by Streptococcus thermophilus was higher than that of the single fermentation of whey protein and blueberry, and the DPPH free radical scavenging capacity reached up to 63% fermented at 24 h. At the same time, the scavenging capacity of superoxide anion radical was increased by 54.94% compared to the initial. Furthermore, the blueberry and whey system fermented at 36 h had the strongest reduction ability and hydroxyl radical scavenging ability. When Lactobacillus bulgaricus fermented whey protein and blueberry for 36 h had the strongest ABTS+? scavenging ability. The anti-lipid peroxidation ability was increased by 24.33% compared with the initial. When mixed strains of Streptococcus thermophilus and Lactobacillus bulgaricus were used to ferment blueberry and whey system for 24 h, the anti-lipid peroxidation ability was higher than that of the system before fermentation for about 24.33%. Therefore, Lactobacillus fermentation can improve and stabilize the antioxidant capacity of the mixed system of whey protein and blueberry juice. The purpose of this study is to provide the theoretical basis for the development of functional blueberry and whey mixed products fermented by lactic acid bacteria, and to provide the research basis for the application of blueberry whey mixed fermentation products in the field of food and medicine.
