金银花叶乳酸杆菌发酵凉茶的研制及其抗氧化活性分析

为获得一款具强抗氧化活性的高保健性金银花叶发酵凉茶,以金银花叶为原材料,通过单因素实验和正交试验,研究了发酵时间、发酵温度、保加利亚乳酸杆菌(L. plantarum 758)接种量及糖的添加量(葡萄糖与蔗糖质量比为3:2)对金银花叶凉茶抗氧化活性的影响并对工艺条件进行了优化,还对比了金银花叶凉茶与市场上常见三种凉茶在抗氧化性及挥发性成分上的差异。结果表明,乳酸杆菌发酵金银花叶凉茶的最佳发酵条件为:发酵时间24 h、发酵温度38℃、接种量4%及糖添加量7%,在此发酵条件下所获得的金银花叶凉茶绿原酸含量达到7.11%,总黄酮含量为22.51%,DPPH自由基清除率为84.23%±3.32%,ABTS自由基清除率为85.30%±2.14%,均显著高于市场上的三种凉茶(P<0.05);金银花叶凉茶中共有挥发性物质32种,其种类和含量都较其它对比组高。总体表明,保加利亚乳酸杆菌(L. plantarum 758)发酵的金银花叶凉茶抗氧化能力突出,具有较高的营养价值和实用功能性。

Preparation of Herbal Tea Fermented by Lactobacillus from Lonicera japonica leaves and Analysis of Its Antioxidant Activity

In order to obtain a kind of Lonicera japonica leaves herbal tea with strong antioxidant activity and high health care, an orthogonal array design based on single factor experiments was employed to examine the influence of time, temperature, inoculum amount of L. plantarum 758 and the concentration of sugar (The mass ratio of glucose to sucrose was 3:2) on the fermentation process. The antioxidant and volatile components of Lonicera japonica leaves herbal tea were compared with those of three common herbal tea in the market. Results showed that the optimal fermentation conditions were determined as fermentation of Lonicera japonica leaves extract containing 7% sugar added at 38 ℃ for 24 h with an inoculum amount of 4%. Under these conditions, the chlorogenic acid content of Lonicera japonica leaves herbal tea reached 7.11%, the total flavonoids content was 22.51%, the DPPH free radical clearance rate was 84.23%±3.32%, and the ABTS free radical clearance rate was 85.30%±2.14%, which were significantly higher than those of the three kinds of herbal tea on the market (P<0.05). There were 32 kinds of volatile substances in Lonicera japonica leaves herbal tea, and their types and contents were higher than those in other comparison groups. Overall, the antioxidant capacity of Lonicera japonica leaves herbal tea fermented by L.plantarum 758 is outstanding, and it has higher nutritional value and practical function.