Abstract:The aim of this study was to investigate the changes in biochemical indicators and antioxidant activity of Blueberry Jiaosu during fermentation. The pH, total number of colonies, and amounts of organic acids, glucose, fructose, and ethanol were monitored to investigate the changes in biochemical indicators. DPPH- and hydroxyl free radical-scavenging rates and changes in procyanidin compounds were assessed to determine the antioxidant ability of Blueberry Jiaosu. The results showed that the pH value initially decreased and then increased, and showed a final value of 3.47. The total number of colonies increased and then decreased cyclically, and the value after 30 d was 0.4×106 cfu/mL. The total contents of glucose and fructose decreased to 73.93 mg/mL. The final contents of ethanol, lactic acid, and acetic acid were 23.69 mg/mL, 5.84 mg/mL, and 4.30 mg/mL, respectively. Qualitative analysis of organic acids showed that Blueberry Jiaosu contained succinic acid, isovaleric acid, citric acid, pyruvic acid, malic acid, and other organic acids. DPPH- and hydroxyl free radical-scavenging rates were increased by 3.2% and 2.92%, respectively, in ten-fold diluted blueberry fermentation liquid. The procyanidin content showed a decreasing trend during fermentation, and was not correlated with DPPH- and hydroxyl free radical-scavenging rates.
