蓝莓酵素发酵过程中的抗氧化活性变化研究

Changes in antioxidant activity of Blueberry Jiaosu during fermentation

摘要:

研究实验室自制蓝莓酵素在30 d发酵过程中生化指标变化及抗氧化性能力，以pH值、菌落总数、葡萄糖、果糖、乙醇和有机酸为指标，考察酵素蓝莓酵素在发酵中生化指标的变化，以DPPH自由基清除率、羟自由基清除率及原花青素的变化评判蓝莓酵素抗氧化性能力。结果表明，发酵过程中，pH值呈先下降后增加趋势，最终pH值为3.47；菌落总数呈现增加降低的循环趋势，30 d后菌落总数为0.4×106 cfu/mL；葡萄糖和果糖总量下降到73.93 mg/mL；最终乙醇、乳酸和乙酸含量分别为23.69 mg/mL、5.84 mg/mL和4.30 mg/mL；有机酸定性实验表明，蓝莓酵素中含有琥珀酸、异戊酸、柠檬酸、丙酮酸和苹果酸等有机酸；稀释10倍蓝莓发酵液的DPPH自由基清除率和羟自由基清除率分别提高了3.2%和2.92%。原花青素在发酵中呈下降趋势，与DPPH自由基清除率及羟自由基清除率无相关性。

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.