Mengniu Dairy (Beijing) Co., Ltd., Beijing, P.R. China.
Beijing Advanced Innovation Center for Food Nutrition and Human Health, Beijing Engineering and Technology Research Center of Food Additives, Beijing Technology and Business University, Beijing 100048, P.R. China.
J Microbiol Biotechnol. 2020 Jun 28;30(6):903-911. doi: 10.4014/jmb.1911.11007.
Addition of probiotics to yogurt with desired health benefits is gaining increasing attention. To further understand the effect of probiotic on the quality and function of fermented milk, probiotic fermented milk (PFM) made with probiotic K25 and yogurt starter ( ssp. and ) was compared with the control fermented milk (FM) made with only the yogurt starter. The probiotic strain was shown to survive well with a viable count of 7.1 ± 0.1 log CFU/g in the PFM sample after 21 days of storage at 4°C. The strain was shown to promote formation of volatiles such as acetoin and 2,3-butanediol with milk fragrance, and it did not cause post-acidification during refrigerated storage. Metabolomics analysis by GC-MS datasets coupled with multivariate statistical analysis showed that addition of K25 increased formation of over 20 metabolites detected in fermented milk, among which γ-aminobutyric acid was the most prominent. Together with several other metabolites with relatively high levels in fermented milk such as glyceric acid, malic acid, succinic acid, glycine, alanine, ribose, and 1,3-dihydroxyacetone, they might play important roles in the probiotic function of K25. Further assay of the bioactivity of the PFM sample showed significant ( < 0.05) increase of ACE inhibitory activity from 22.3% at day 1 to 49.3% at day 21 of the refrigerated storage. Therefore, probiotic K25 could be explored for potential application in functional dairy products.
添加具有预期健康益处的益生菌到酸奶中越来越受到关注。为了进一步了解益生菌对发酵乳质量和功能的影响，比较了用益生菌 K25 和酸奶发酵剂（ssp. 和 ）制成的益生菌发酵乳（PFM）与只用酸奶发酵剂制成的对照发酵乳（FM）。结果表明，益生菌菌株在 4°C 下储存 21 天后，在 PFM 样品中的活菌数为 7.1±0.1logCFU/g，存活良好。该菌株被证明能促进具有奶香的挥发性物质如乙酰醇和 2,3-丁二醇的形成，并且在冷藏过程中不会引起后酸化。GC-MS 数据集结合多元统计分析的代谢组学分析表明，添加 K25 增加了发酵乳中检测到的 20 多种代谢物的形成，其中γ-氨基丁酸最为突出。与发酵乳中其他几种含量较高的代谢物（如甘油酸、苹果酸、琥珀酸、甘氨酸、丙氨酸、核糖和 1,3-二羟基丙酮）一起，它们可能在 K25 的益生菌功能中发挥重要作用。进一步对 PFM 样品的生物活性进行检测，结果表明 ACE 抑制活性从冷藏储存第 1 天的 22.3%显著增加（<0.05）到第 21 天的 49.3%。因此，益生菌 K25 可以探索用于功能性乳制品的潜在应用。
