不同乳酸菌发酵对红枣汁贮藏品质的影响

Effect of various lactic acid fermentation on quality of jujube juice during storage

比较益生乳酸菌发酵对红枣汁贮藏品质的影响,以鲜榨并经杀菌的红枣浆为实验对象,分别接种德式乳杆菌、嗜热链球菌和植物乳杆菌进行纯种乳酸菌发酵,比较发酵24 h后,并在4℃贮藏过程中乳酸菌活菌数、可溶性固形物、p H、可滴定酸、抗坏血酸、总酚、多糖、蛋白质和色泽等变化。结果显示,德式乳杆菌在发酵24 h贮藏7 d时达到最大的活菌量(6.54 log_(10)CFU/m L),嗜热链球菌在贮藏14 d时达到最大的活菌量(6.38 log_(10)CFU/m L);德式乳杆菌发酵的红枣汁可溶性固形物含量和p H低于嗜热链球菌组和植物乳杆菌组,且产生的可滴定酸含量显著高于这两组。然而,三种乳酸菌发酵对红枣汁中的抗坏血酸、多酚和蛋白质含量没有显著影响。经低温贮藏28 d后,德式乳杆菌组的L*值在贮藏14 d后显著高于其他两组。综合以上,采用德式乳杆菌发酵红枣浆可获得酸度更低,色泽更透亮的发酵红枣汁产品。

With the aim to compare the effects of lactic acid bacteria fermentation on the quality of jujube juice during storage,the changes of lactic acid bacterial number,p H,titratable acid,ascorbic acid,total phenolics,polysaccharide,protein and color in pasteurised jujube juices were studied after fermentation of 24 hours and during storage of 4 ℃ when fermented with various lactic acid bacteria（ Lactobacillu delbrueckii,Streptococcus thermophiles and Lactobacillus plantarum）. Results showed that the jujube juice fermented with Lactobacillu delbrueckii reached high viable count at 7 days（ 6.54 log_（10） CFU / m L）,while the highest amount of Streptococcus thermophiles viable bacteria count was occurred at 14 days of storage（ 6.38 log_（10） CFU / m L）.Moreover,the soluble solids content and p H value of jujube juice fermented with Lactobacillu delbrueckii were lower than that of Streptococcus thermophiles and Lactobacillus plantarum,and titration acid content were significantly higher than that of the other two groups.However,the contents of ascorbic acid,total phenolics and protein content in jujube juices fermented by three kinds of lactic acid bacteria showed no significant difference. Three kinds of lactic acid bacteria fermentation of jujube juices after storage for 28 days,the L＊value of Lactobacillu delbrueckii group at 14 days after storage was significantly higher than that of the other two groups.Based on the above,the low acidity and bright color of fermented jujube juice can be obtained by using Lactobacillu delbrueckii.