保加利亚乳杆菌发酵黄瓜汁产物分析及生物活性评价

Products analysis of cucumber juice fermentated by Lactobacillus bulgaricus and biological activity evaluation

以黄瓜与鲜牛奶为原料,利用保加利亚乳杆菌(Lactobacillus bulgaricus)对黄瓜牛奶复合物进行发酵。并对发酵液的pH值、总酸、总糖、总酚、乳酸含量和抗氧化性进行分析。同时利用气相色谱-质谱对发酵液的挥发性成分进行分析。采用的发酵工艺为黄瓜汁∶纯牛奶=7∶3(V/V),保加利亚乳杆菌接种量0.01%,初始pH值6.1,发酵温度37℃,发酵时间3 d。在此工艺下对提取的样品进行分析,测得发酵乳的总酸含量为50.5 g/L,总酚含量为0.165 mg/mL,其羟自由基清除率达87%,DPPH自由基清除率达85.12%。总抗氧化能力最高与0.85 mmol/L的Trolox的抗氧化能力相同。发酵液的挥发性成分中,烷类化合物(68.40%)和酯类化合物(10.61%)含量较高,酸类化合物(5.03%)和酮类化合物(0.98%)含量较低。

Using cucumber and fresh milk as raw materials,cucumber-milk compound beverage was fermented by Lactobacillus bulgaricus.Then the pH,total acid,total sugar,total phenol,lactic acid content and antioxidant activity of the fermentation broth were analyzed.At the same time,the volatile components of the fermentation broth were analyzed by GC-MS.The fermentation process was cucumber juice to pure milk ratio 7∶3(V/V),L.bulgaricus inoculum 0.01%,initial pH 6.1,fermentation temperature 37℃and fermentation time 3 d.The extracted sample was analyzed under the process,and the total acid content of the fermented milk was 50.5 g/L,the total phenol content was 0.165 mg/ml,the hydroxyl radical scavenging rate was 87%,the DPPH free radical scavenging rate reached 85.12%,and the total antioxidant capacity was the same as the antioxidant capacity of 0.85 mmol/L Trolox.Among the volatile components of fermentation broth,alkanes(68.40%)and esters(10.61%)were higher,acids(5.03%)and ketones(0.98%)were lower.