不同乳酸菌发酵葡萄酵素过程中代谢产物及其抗氧化特性分析

Analysis of the Metabolic Components and Antioxidant Properties of Different Lactic Acid Bacteria during Grape Fermentation

以巨峰葡萄为原料,选用4种不同的乳酸菌进行发酵,对发酵过程中的代谢产物和抗氧化能力进行测定。结果表明:试验选择的4种乳酸菌均能在发酵过程中较好的生长且均能产酸,产酸能力大小依次为干酪乳杆菌﹥植物乳杆菌﹥副干酪乳杆菌﹥鼠李糖乳杆菌,发酵15 d后,干酪乳杆菌总酸含量最大,达8.40 g/L;不同乳酸菌在发酵过程中总酚含量与超氧化物歧化酶(superoxide dismutase,SOD)酶活变化一致,均呈先增加后减少的趋势,干酪乳杆菌、副干酪乳杆菌、鼠李糖乳杆菌在发酵第7天时总酚含量最大,分别为3.53、3.49、3.59 mg/mL,植物乳杆菌在发酵第9天时总酚含量最大,为3.62 mg/mL;干酪乳杆菌在发酵第6天时SOD酶活最大,为284.57 U/mL,副干酪乳杆菌在发酵第7天最大,为274.26 U/mL,植物乳杆菌和鼠李糖乳杆菌在发酵第9天最大,分别为262.22 U/mL和272.33 U/mL;抗氧化性测定指标DPPH自由基、ABTS+自由基清除率和发酵过程中铁离子还原能力(ferric reducing antioxidant power,FRAP)变化趋势与总酚含量的变化趋势大致相同。综合比较,这4种乳酸菌均能提高葡萄发酵液的总酚含量和抗氧化活性。

Kyoho grapes were used as a raw material.Four strains of lactic acid bacteria were selected for fermentation.With each strain,the effect of fermentation on metabolites and antioxidant capacity of the product were determined.Each of the four lactic acid bacteria selected for these experiments grew well and produced acid via fermentation.The strains'acid production capacities were ranked as follows:Lactobacillus casei>Lactobacillus plantarum>Lactobacillus paracasei>Lactobacillus rhamnosus.After 15 days of fermentation,the total acid content was highest with Lactobacillus casei,reaching 8.40 g/L.Changes in total phenol content and superoxide dismutase(SOD)activity caused by the different lactic acid bacteria during fermentation were consistent among strains,initially increasing,then decreasing.Total phenol contents when using Lactobacillus casei,Lactobacillus paracasei,and Lactobacillus rhamnosus were highest on the 7th day of fermentation(3.53 mg/mL,3.49 mg/mL and 3.59 mg/mL,respectively).Maximum total phenol content with Lactobacillus plantarum was 3.62 mg/mL on day 9 of fermentation.On day 6 of fermentation,Lactobacillus casei displayed the highest SOD activity(284.57 U/mL).Lactobacillus paracei,Lactobacillus plantarum,and Lactobacillus rhambutus each displayed their highest SOD activities(274.26 U/mL,262.22 U/mL and 272.33 U/mL,respectively)on day 7 of fermentation.Trends for variation in the antioxidant indiced for DPPH free radical,ABTS+free radical,and ferric reducing antioxidant power(FRAP)were roughly the same as those for total phenol content.These results indicated that these four lactic acid bacteria could enhance total phenol content and antioxidant activity in grape fermentation broth.