以自制总酸含量为2.38%（以苹果酸计）的青梅汁为原料，采用植物乳杆菌LP-L134-1-P的苹果酸乳酸发酵（MLF）对青梅汁进行生物降酸，研究了在青梅汁中植物乳杆菌LP-L134-1-P接种量、pH、温度、糖含量和柠檬酸-柠檬酸钠的对生长及其酸代谢的影响。结果表明：由植物乳杆菌LP-L134-1-P发酵的青梅汁，其总酸总体呈先上升再下降的趋势；pH值为3.50，接种量为108 CFU/g时，能正常引发MLF，且接种量越大，MLF的降酸幅度越大；接种量为109 CFU/g，pH值为3.50时，发酵温度≥25 ℃时，才能引发MLF；接种量为109 CFU/g，pH值≥3.10时，即能引发MLF，且pH值越高，越容易发生MLF；在青梅汁中添加1.00%的葡萄糖，植物乳杆菌LP-L134-1-P使体系的酸度只升不降，证实植物乳杆菌LP-L134-1-P优先代谢葡萄糖转化成乳酸，抑制了MLF的发生；在柠檬酸-柠檬酸钠缓冲体系中，植物乳杆菌LP-L134-1-P不能使体系的酸度降低，证实植物乳杆菌LP-L134-1-P不能单独利用柠檬酸作为碳源，进行MLF。

Plum juice was used as material and Lactobacillus Plantarum LP-L134-1-P was used as inoculation strain for malolactic fermentation (MLF) to reduce acids in juice. The effects of the inoculation amount, pH, fermentation temperature, sugar content, and sodium citrates buffer system on deacidification and the growth of Lactobacillus Plantarum LP-L134-1-P in plum juice were studied. The results showed that the total acids increased at the first stage and then decreased during the fermentation. The MLF proceeded normally at pH 3.50 with the inoculation amount of 108 CFU/g. And the bigger inoculation amount was, the more acids were reduced through MLF. When the inoculation amount was increased to 109 CFU/g and pH was 3.50, the MLF could be performed only if the fermentation temperature was more than 25 ℃. It would be easy to perform MLF when the inoculation amount was 109 CFU/g and pH was no less than 3.10. The acidity of plum juice went up with addition of 1.00% glucose, indicating that glucose was prior to convert into lactic acid, thus inhibiting the MLF. In sodium citrates buffer system, the acidity was not reduced, proving that Lactobacillus Plantarum LP-L134-1-P could not use citric acid as carbon resource to run MLF.

广东省教育部产学研结合项目（2011B090400311）