益生菌发酵蓝莓花色苷的代谢规律

Metabolism of Blueberry Anthocyanins During Probiotic Fermentation

选用嗜热链球菌、两岐双歧杆菌、植物乳杆菌进行纯种发酵含有蓝莓花色苷提取液的培养液,考察了益生菌发酵过程中活菌数、体外抗氧化性、有机酸、单体花色苷和酚酸等组分的变化情况。结果表明,发酵48 h后,三种益生菌的活菌数均增至8.0 lg CFU/mL左右,两岐双歧杆菌的活菌数最高(P<0.05),发酵后不同菌株发酵样的ABTS+·清除能力显著提升(P<0.05),其中两岐双歧杆菌发酵样品抗氧化能力最强(P<0.05);但植物乳杆菌发酵样品中乳酸含量最高(P<0.05);发酵过程中单体花色苷含量呈下降趋势,两岐双歧杆菌发酵样品花色苷组分与其它两株菌发酵的样品差异较大;绿原酸、对香豆酸和咖啡酸的含量总体呈现下降趋势,而没食子酸、丁香酸和阿魏酸含量呈上升趋势,主成分分析图中三株益生菌发酵样的分布差异较大。以上结果为进一步解释益生菌发酵代谢花色苷的机理提供了参考。

Streptococcus thermophilus,Bifidobacterium bifidum and Lactobacillus plantarum were used to ferment the culture medium containing blueberry anthocyanin extracts.The changes of bacterial number,antioxidant capacity of fermented medium in vitro,and profiles of organic acids,anthocyanins and phenolic acids were investigated.The results showed that after 48 h of fermentation,the number of viable strains of the three probiotics increased to about 8.0 lg CFU/mL,and the number of viable strains of Bifidobacterium bifidum was the highest(P<0.05).Probiotic fermentation significantly(P<0.05)enhanced the scavenging capacity of ABTS+·radicals of culture medium in vitro,the medium fermented by Bifidobacterium bifidum had the strongest antioxidant capacity among all the mediums.Moreover,Lactobacillus plantarum synthetized more lactic acid than the other two microbial strains in the culture medium containing blueberry anthocyanins.Anthocyanin contents in the medium decreased gradually during probiotic fermentation.The anthocyanin profile of medium fermented by Bifidobacterium bifidum was significantly(P<0.05)different from that fermented by Lactobacillus plantarum and Streptococcus thermophilus according to principal component analysis.Besides,probiotic fermentation led to the declines of contents of chlorogenic acid,p-coumaric acid and caffeic acid.Instead,contents of gallic acid,syringic acid and ferulaic acid in the culture medium exhibited an increasing trend.The phenolic acid profile was also markedly affected by the applied microbial strains.The aforementioned results can provide guidance for further investigation of metabolisms of anthocyanins during probiotic fermentation of fruit juices.