复合菌种发酵条件对猕猴桃饮料抗氧化活性的影响

目的 研究发酵条件对猕猴桃饮料抗氧化活性的影响。方法 以猕猴桃为原料，利用植物乳杆菌、嗜酸乳杆菌复合菌种发酵制备猕猴桃饮料，以猕猴桃发酵饮料的1,1-二苯基-2-三硝基苯肼(2,2-diphenyl-1-picrylhydrazyl, DPPH)自由基清除率为考察指标，通过单因素和响应面试验确定最佳发酵工艺，并对猕猴桃饮料发酵前后的主要理化指标进行比较。结果 猕猴桃饮料的最佳发酵工艺参数为：发酵液初始pH 5.5，发酵时间21 h，接种量为1.6%（v/v），该条件下发酵的猕猴桃饮料DPPH自由基清除率可高达90.28%1.43%，较发酵前65.47%1.12%有显著提升(P<0.05)；OH自由基清除率和总黄酮含量分别由42.67%0.78%、(3.210.01) mg/mL提高到61.21%0.94%、(3.670.02) mg/mL；pH值由5.480.01降低到3.730.01；可溶性固形物和维生素C含量分别由13.26%0.01%、(60.582.14) mg/100 g下降到12.98%0.01%、(58.391.22) mg/100 g，变化不明显(P<0.05)。结论 最佳发酵条件下制备的猕猴桃发酵饮料抗氧化较强，总黄酮含量增加，可溶性固形物和和维生素C含量变化不明显。

Effects of fermentation conditions of compound strains on antioxidant activity of fermented kiwifruit beverage

Objective To study the effect of fermentation conditions on antioxidant activity of kiwi fruit beverage. Methods Kiwifruit beverage was prepared by fermentation with compound strains of Lactobacillus plantarum and Lactobacillus acidophilus. The free radical scavenging rate of 1,1-diphenyl-2-trinitrophenylhydrazine (DPPH) in kiwifruit fermented beverage was used as the index. The optimal fermentation process was determined by single factor and response interview. The main physical and chemical indexes of kiwi fruit beverage before and after fermentation were compared. Results The optional process parameters were as follows: Initial pH value of the fermentation broth 5.5, fermentation time 21 h, and the inoculation amount of the seed solution 1.6%. Under this circumstance, the DPPH free radical scavenging activity of the fermented beverage reached 90.281.43%, which was significantly higher than 65.47%1.12 % before fermentation (P<0.05). Furthermore, OH radical scavenging rate increased from 42.67%0.78% to 61.21%0.94%, and the content of total flavonoids increased from (3.210.01) mg/mL to (3.670.02) mg/mL. PH value decreased from 5.480.01 to 3.730.01; soluble solids decreased from 13.26%0.01% to 12.98%0.01%, and vitamin C content decreased from (60.582.14) mg/100g to (58.391.22) mg/100g. There was no significant change in the content of soluble solids and vitamin C (P<0.05). Conclusion The fermented kiwifruit beverage prepared under the optimum fermentation conditions has strong antioxidation, the content of total flavonoids increased, and the content of soluble solids and vitamin C does not change significantly.