火龙果皮乳酸菌发酵产品体外抗氧化能力研究

为开发火龙果皮益生菌发酵新产品,实现对其增值利用,将火龙果皮通过植物乳杆菌发酵,采用不同的自由基体系对其发酵产品的体外抗氧化活性进行测定,并对其发酵前后色素、多糖、总黄酮含量变化进行分析。结果表明,发酵前、后火龙果皮汁对超氧阴离子（O₂^-·）、DPPH自由基具有较强的清除能力,对羟基自由基（·OH）、亚硝酸根离子（NO₂^-）也具有一定的清除作用;且清除能力均随浓度增大而增强;发酵后对羟基自由基（·OH）、超氧阴离子（O₂^-·）、亚硝酸根离子（NO₂^-）、DPPH自由基的IC₅₀分别为0.77、0.33、0.47、0.17 m L/m L,较发酵前分别减少25.96%、28.26%、47.78%、57.50%;相同浓度下,发酵可有效提高火龙果皮汁的自由基清除能力,但提高幅度随浓度增大而逐渐减小;发酵后色素和总黄酮浓度较发酵前下降,但多糖含量增高。说明火龙果皮汁经植物乳杆菌发酵可进一步提高其抗氧化能力,为火龙果皮保健功能及益生菌发酵产品开发提供理论依据。 

Antioxidant activity of pitaya peel beverage fermented by lactic acid bacteria in vitro

To develop probiotic fermented new products and realize the value-added utilization of pitaya peel, the antioxidant ability of pitaya peel beverage fermented by Lactobacillus plantarum was investigated by means of different free radicals antioxidant experiments in vitro, and the content of pigment, polysaccharide, total flavonoid of unfermented and fermented were analyzed.The results showed that the pitaya peel beverage both unfermented and fermented had a strong scavenging ability to superoxide anion ( O₂^-·) , DPPH free radicals, and a certain scavenging ability to hydroxyl free radical (·OH) , nitrite ion ( NO₂^-) , within a certain range, the clearance rate increased with the increase of sample concentration.The IC₅₀ of fermented pitaya peel beverage to hydroxyl free radical (·OH) , superoxide anion ( O₂^-·) , nitrite ion ( NO₂^-) and DPPH free radicals respectively were 0.77, 0.33, 0.47, 0.17 m L/m L, which decreased by 25.96%, 28.26%, 47.78%, 57.50% respectively compared with unfermented.Fermentation could effectively improved the free radical scavenging capacity of pitaya peel beverage at the same concentration, but the increase amplitude decreased gradually with the increase of concentration, pigment and total flavonoid concentration decreased after fermentation, but the content of polysaccharide increased.This suggested that fermented by Lactobacillus plantarum could further improve the antioxidant capacity of pitaya peel, provided theoretical basis for the development of pitaya peel hygienical and probiotic fermented products.