红曲霉与植物乳杆菌发酵普洱茶的抗氧化活性比较

Comparison of the Antioxidant Activities of Fermented Pu-erh Teas with Monascus and/or Lactobacillus plantarum

摘要:

该文探究添加红曲霉和植物乳杆菌发酵对普洱茶生化成分和抗氧化活性的影响。采用相关系数法分析主要生化成分和抗氧化指标的相关性。实验表明，六个发酵茶样的水浸出物、黄酮、茶多酚含量范围分别是50.64%~52.50%、0.77~0.95 mg/g、13.21%~11.07%，单接植物乳杆菌R的茶多酚含量最高为13.21%。不同处理的茶样体外抗氧化能力存在显著差异（P<0.05），R的总抗氧化能力、DPPH自由基清除率和羟自由基清除率最高（10.36 μg Trolox/mL、91.59%、29.43%）。相关性显示，茶红素、茶褐素与抗氧化能力呈负相关，但不显著；咖啡碱、茶多酚、茶黄素、总黄酮指标与抗氧化能力都有一定的显著相关性，其中茶多酚与总抗氧化能力、DPPH自由基清除率呈极显著相关（P<0.01），相关系数为0.74、0.95。添加菌种发酵的普洱茶具有较强抗氧化能力，且单菌种发酵普洱茶的抗氧化能力比混合发酵普洱茶的抗氧化能力更强，其中R的抗氧化能力最好。

Abstract:

The effects of the fermentation with Monascus and/or Lactobacillus plantarum on the biochemical components and antioxidant activities of Pu-erh teas were investigated. The correlation coefficient method was used to analyze the correlation between the main biochemical components and antioxidant indexes. The experiments showed that the contents of water extract, flavonoids and tea polyphenols of the six fermented tea samples were in the range of 50.64%~52.50%, 0.77~0.95 mg/g and 13.21%~11.07%, respectively, with the tea fermented with L.plantarum alone (R) having the highest tea polyphenol content (13.21%). There were significant differences (P<0.05) in the in vitro antioxidant capacity of the tea samples subjected to different treatments. R had the highest total antioxidant capacity, DPPH scavenging rate and hydroxyl radical scavenging rate (10.36 μg Trolox/mL, 91.59%, 29.43%, respectively). The correlation analysis showed that theophyllin and theaflavin were negatively correlated with antioxidant capacity (though not significantly); caffeine, tea polyphenols, theaflavin and total flavonoid indexes were significantly correlated with antioxidant capacity, among which tea polyphenols were highly significantly correlated with total antioxidant capacity and DPPH radical scavenging rate (P<0.01) with the correlation coefficients being 0.74 and 0.95, respectively. The Pu-erh teas fermented with added strains had a relatively strong antioxidant capacity, and the antioxidant capacity of the fermented Pu-erh tea with a single strain was stronger than that with mixed strains, with the R having the highest antioxidant capacity.