植物乳杆菌R23酵解枇杷汁有机酸的动态分析

Dynamic Analysis of Organic Acids in Glycolytic Loquat Juice Using Lactobacillus Plantarum R23

目的:将植物乳杆菌R23应用于枇杷果汁中,为乳酸发酵质量调控及优质枇杷乳酸发酵饮料研发提供理论依据。方法:以枇杷果汁为原料,采用植物乳杆菌R23进行乳酸发酵,应用HPLC法分析发酵过程的有机酸组成变化,研究接种量、原果酸含量对其酸代谢的影响。结果与结论:由植物乳杆菌R23酵解的枇杷果汁总酸呈现先降后升的趋势。发酵前期,主要以苹果酸为碳源,进行苹果酸-乳酸发酵(MLF),苹果酸含量减少直至消失,而乳酸、琥珀酸含量增加,总酸下降;MLF结束后进行异型乳酸发酵,产物除乳酸外,主要为乙酸,果汁总酸持续上升。完成MLF的时间与接种量呈负相关,与果汁的果酸含量呈正相关。适度的糖酵解有利于形成良好的枇杷发酵果汁风味。

Objective：To provide theoretical basis for the quality regulation of lactic acid fermentation and development of the lactic acid fermentation loquat beverage,the Lactobacillus plantarum R23 was used in loquat juice.Methods：Loquat fruit juice was used as material and Lactobacillus plantarum R23 was used as strain for lactic acid fermentation.The changes of organic acids component during the fermentation were analyzed by HPLC method,and the effects of the inoculation amount and the original fruit acid contents on acid matebolism of Lactobacillus plantarum R23 were studied.Results and Conclusions：A trend that an acids decreasing at the first stage of the experiment and at the later stage it turns to acids production was present during the fermentation that loquat fruit juice was glycolysis by Lactobacillus plantarum R23.At the beginning of fermentation,malic acid was the main carbon source for maloalctic fermentation,so its contents reduced until it disappeared;at the meantime the contents of lactic acid and the succinic acid increased,but the total acid of juice reduced.After the end of maloalctic fermentation,sugar was the main carbon source;and the products were mainly acetic acid and some lactic acid;the total acid of juice continuous increased.The accomplish time of MLF had negative corretation on the inoculation amount of Lactobacillus plantarum R23 and had positive corretation on the fruit acid contents;the moderate glycolysis was beneficial to form the good flavor of the lactic acid fermentation loquat fruit juice.