Survival of probiotic bacteria in fruit juice jelly products

The aims of this work were to determine the sensory evaluation (in terms of color, odor, flavor, texture and overall liking) of three types of fruit juice jelly products, growth curves of Lactobacillus acidophilus TISTR 1338 and L. casei TISTR 390 and their survivals in fruit juice jelly products during storage at 5ฐC for 9 days. The sensory scores showed that there was no significant difference of overall liking scores among jelly products. According to their growth curves, both probiotic bacteria had entered the stationary phase with an average of 9 log cfu/ml after incubation for 26 h. Probiotic bacteria were cultured for 26 h for studying the survival of probiotic bacteria in fruit juice jelly products. It was found that the numbers of L. acidophilus TISTR 1338 and L. casei TISTR 390 decreased from the initial numbers of 9.23 log cfu/g and 8.97 log cfu/g to 6.80 log cfu/g and 7.73 log cfu/g, respectively, after 9 days of refrigerate storage. However, there was no significant difference (p > 0.05) between viabilities of L. acidophilus TISTR 1338 and L. casei TISTR 390 on day 9. The survival of bacteria reduced during storage; however the final cell concentrations were still higher than the minimum therapeutic levels (?5 Log cfu/g) for probiotics in the products.

本研究旨在通过感官评价（涵盖色泽、气味、风味、质地及整体喜好度）分析三款果汁果冻产品的品质，并探究嗜酸乳杆菌（Lactobacillus acidophilus）TISTR 1338与干酪乳杆菌（Lactobacillus casei，简称L. casei）TISTR 390的生长曲线，以及二者在5℃冷藏条件下储存9天的果汁果冻产品中的存活特性。感官评分结果显示，三款果冻产品的整体喜好度评分无显著差异。基于生长曲线分析，两种益生菌在培养26小时后均进入稳定期，平均活菌数可达9 log cfu/ml。后续实验中，我们将益生菌培养26小时以研究其在果汁果冻中的存活情况。结果表明，嗜酸乳杆菌TISTR 1338与干酪乳杆菌TISTR 390的初始活菌数分别为9.23 log cfu/g与8.97 log cfu/g，经9天冷藏储存后分别降至6.80 log cfu/g与7.73 log cfu/g。不过在储存第9天时，两种益生菌的活菌存活率无显著差异（p > 0.05）。尽管储存过程中活菌数量有所减少，但最终活菌浓度仍高于益生菌产品所需的最低有效阈值（≥5 log cfu/g）。