不同乳酸菌发酵留兰香纯露的抗氧化活性比较

以不同乳酸菌（鼠李糖乳杆菌、植物乳杆菌、粪肠球菌、嗜酸乳杆菌）发酵的留兰香纯露为研究对象，通过测定其DPPH 自由基清除能力、ABTS+自由基清除能力、·OH 清除能力、O2-自由基清除能力、总还原力，对其抗氧化活性进行评价。结果表明，留兰香纯露具有一定的体外抗氧化活性，且在一定范围内，体积分数越高，抗氧化性越好。与未发酵的纯露相比，留兰香纯露经不同乳酸菌发酵后在抗氧化方面更具优势。经发酵的留兰香纯露对DPPH 自由基、ABTS+自由基、·OH、O2-自由基的清除能力以及总还原力明显高于留兰香纯露及乳酸菌发酵液，尤其是·OH 清除能力和总还原力。对比不同体积分数纯露经不同乳酸菌发酵后体外抗氧化能力，结果表明，当留兰香纯露体积分数为60%时，其DPPH 自由基、ABTS+自由基、·OH、O2-自由基的清除能力及总还原力均较高。综上所述，经鼠李糖乳杆菌、植物乳杆菌、粪肠球菌、嗜酸乳杆菌发酵的留兰香纯露均有良好的体外抗氧化能力，且以60%时抗氧化力较佳。

Comparison on the Antioxidant Activities of Spearmint Hydrolates Fermented by Different Lactic Acid Bacteria

The DPPH·，ABTS+·，·OH，and ·O2- scavenging activities and the total reducing power of spearmint hydrolates fermented by different lactic acid bacteria（Lactobacillus rhamnosus，Lactobacillus plantarum，Enterococcus faecalis，and Lactobacillus acidophilus）were measured to evaluate the antioxidant activities of the hydrolates. The results showed that spearmint hydrolates had an antioxidant activity in vitro，which enhanced with the increase in the volume fraction. Compared with the spearmint hydrolate without fermentation，the spearmint hydrolates fermented by different lactic acid bacteria showed increased antioxidant activities. The DPPH·，ABTS+·，·OH，and·O2-scavenging activities and the total reducing power of the fermented spearmint hydrolates were higher than those of the unfermented spearmint hydrolate and the fermentation broths of lactic acid bacteria without spearmint hydrolate（P＜0.05），especially the ·OH scavenging activity and the total reducing power. In addition，the antioxidant activities of spearmint hydrolates with different volume fractions after fermentation were compared in vitro. When the volume fraction of spearmint hydrolate was 60%，the DPPH·，ABTS+·，·OH，and ·O2- scavenging activities and the total reducing power of the hydrolate were the highest. In conclusion，the spearmint hydrolates fermented by L. rhamnosus，L. plantarum，E. faecalis，and L.acidophilus all had strong antioxidant activities in vitro，which were the highest at the hydrolate volume fraction of 60%.