植物乳杆菌和发酵乳杆菌发酵对蓝莓花色苷的影响

Effects of Lactobacillus plantarum and L.fermentum Fermentation on Anthocyanins in Blueberry

选用植物乳杆菌(Lactobacillus plantarum)FM-LP-9和发酵乳杆菌(Lactobacillus fermentum)FM-LP-SR6分别对蓝莓花色苷进行发酵,考察发酵过程中菌落总数、pH值、色差、总黄酮含量、总糖含量、总花色苷含量、单体花色苷含量、有机酸含量等指标的变化规律。结果表明,经48 h发酵后,两种乳杆菌的菌落总数均能达到9.0 lg(CFU/mL)以上,发酵液的pH值降至3.6,总糖含量相较于发酵前分别降低了48.65%和58.97%,总黄酮含量分别增加至11.4、11.8 mg/L,总花色苷含量分别降低了48.63%和46.06%,色差值升高,颜色变暗。两株乳杆菌均能代谢花色苷和转化酚类物质,发酵过程中花色苷含量呈下降趋势,主成分分析得出两株乳杆菌发酵花色苷后的单体花色苷组分差异较大,主要来自飞燕草素-3-O-葡萄糖苷和矢车菊素-3-O-葡萄糖苷。此外,两株菌发酵后,发酵液中的乳酸、乙酸含量升高,草酸、苹果酸、柠檬酸含量降低。

Lactobacillus plantarum FM-LP-9 and L.fermentum FM-LP-SR6 were used to ferment blueberry anthocyanins,respectively.Further studies were carried out to examine the changes of total bacteria count,pH,color difference,total flavonoid content,total sugar content,total anthocyanin content,anthocyanin monomer content and organic acid content during the fermentation.The results showed that the total bacteria counts of both Lactobacillus strains were higher than 9.0 lg(CFU/mL)after fermentation for 48 h,the pH of the fermentation broth decreased to 3.6,the total sugar contents decreased by 48.65%and 58.97%,respectively,the total flavonoid contents increased to 11.4 mg/L and 11.8 mg/L,respectively,the total anthocyanin contents decreased by 48.63%and 46.06%,respectively,the color difference increased and the color became darker.Both Lactobacillus strains could metabolize anthocyanins and transform phenolic substances,while the content of anthocyanins decreased during the fermentation.Further principal component analysis showed that the anthocyanin monomer components of anthocyanins after the fermentation with Lactobacillus strains were significantly different,mainly in delphinin-3-O-glucoside and cyanidin-3-O-glucoside.In addition,the contents of lactic acid and acetic acid in the broth increased,while the contents of oxalic acid,malic acid and acetic acid decreased after fermentation by the two strains.