苹果渣乳酸菌发酵工艺条件优化

Optimization of apple residue lactobacillus fermentation

为了充分利用苹果渣,开发附加值高的苹果产品,提升苹果深加工水平,采用苹果渣与新鲜苹果复配浸提汁液,得到的浸提汁进行乳酸发酵.以总酸为主要指标对乳酸发酵菌种进行了选择;以乳酸菌浓度为指标通过单因素实验确立了碳源、氮源,并采用正交试验对发酵工艺参数进行了优化.结果表明:优百伦发酵剂为乳酸发酵适宜菌种,其适宜发酵条件为初始pH6.5、接种量0.4%、蔗糖添加量3%、玉米浆添加量0.5%,在此条件下,所得乳酸醪液单位体积活菌数含量大于9.43×10~8 CFU/mL,发酵液总酸含量大于7.74g/L,有利于乳酸饮料的生产与开发.

In order to make full use of the apple pomace and improve the level of apple deep processing,the apple pomace and fresh apple were used as materials to extract juice in aqueous solution.Then,the extracted juice was fermented by Lactobacillus to prepare a lactic acid solution.Based on criteria including total acid content and cell concentration,an ideal lactic acid bacteria was screened.And the ideal carbon source and nitrogen source for selected lactic acid strain were determined by single factor experiments based on a criteria of cell concentration.The fermentation parameters were optimized by orthogonal test design.Results show that the idea inoculums for lactic acid fermentation is yoghurt starter.The optimal fermentation conditions are the initial pH of 6.5,inoculum size of 0.4%,sucrose content 3%,corn steep liquor 0.5%.Under the conditions,the cell concentration of Lactobacillus was more than 9.43×108 CFU/mL and the total acid content is more than 7.74g/L in the fermentation broth,which is favorite to production and development of lactic acid beverage.