Western Dairy Center, Utah State University, Logan 84322-8700, USA.
J Dairy Sci. 2012 Nov;95(11):6274-81. doi: 10.3168/jds.2012-5476. Epub 2012 Sep 12.
An erythromycin-resistant strain of probiotic Lactobacillus paracasei ssp. paracasei LBC-1 (LBC-1e) was added to part-skim Mozzarella cheese in alginate-microencapsulated or free form at a level of 10(8) and 10(7)cfu/g, respectively. Survival of LBC-1e and total lactic acid bacteria (LAB) was investigated through the pasta filata process of cheese making (in which the cheese curd was heated to 55 °C and stretched in 70 °C-hot brine), followed by storage at 4 °C for 6 wk and simulated gastric and intestinal digestion. This included incubation in 0.1 M and 0.01 M HCl, 0.9 M H(3)PO(4), and a simulated intestinal juice consisting of pancreatin and bile salts in a pH 7.4 phosphate buffer. Some reductions were observed in both free and encapsulated LBC-1e during heating and stretching, with encapsulated LBC-1e surviving slightly better. Changes in total LAB losses during heating and stretching did not reach statistical significance. During storage, a decrease was observed in total LAB, but no statistically significant decrease was observed in LBC-1e. Survival during gastric digestion in HCl was dependent on the extent of neutralization of HCl by the cheese, with more survival in the weaker acid, in which pH increased to 4.4 after cheese addition. The alginate microcapsules did not provide any protection against the HCl. It is interesting that survival of the encapsulated LBC-1e was greater during incubation in H(3)PO(4) than in the HCl gastric juices. Proper selection of simulated gastric digestion media is important for predicting the delivery of probiotic bacteria into the human intestinal tract. Neither free nor encapsulated LBC-1e was affected by incubation in the pancreatin-bile solution. Based on the level of probiotic bacteria in cheese needed to provide a health benefit and its survival during simulated gastric digestion, as determined in this study, it should theoretically be possible to lower the amount that needs to be ingested in cheese by up to a factor of 10(3) compared with other fermented dairy foods or when consumed as supplements.
将耐红霉素的益生菌副干酪乳杆菌亚种副干酪乳杆菌 LBC-1（LBC-1e）的浓缩物以 10(8)和 10(7)cfu/g 的水平添加到部分脱脂马苏里拉干酪中，分别用藻酸盐微囊或游离形式。通过奶酪制作的意大利乳清干酪过程（其中奶酪凝乳在 55°C 下加热并在 70°C 的热盐水中拉伸）研究了 LBC-1e 和总乳酸菌（LAB）的生存能力，然后在 4°C 下储存 6 周并模拟胃和肠消化。这包括在 0.1 M 和 0.01 M HCl、0.9 M H(3)PO(4)和由胰蛋白酶和胆汁盐组成的 pH 7.4 磷酸盐缓冲液中的模拟肠液中孵育。在加热和拉伸过程中，游离和包封的 LBC-1e 都观察到一些减少，包封的 LBC-1e 存活稍好。加热和拉伸过程中总 LAB 损失的变化没有达到统计学意义。在储存过程中，总 LAB 减少，但 LBC-1e 没有观察到统计学上的减少。在 HCl 中的胃消化过程中的存活取决于奶酪中和 HCl 的程度，在较弱的酸中存活更多，在奶酪添加后 pH 增加到 4.4。藻酸盐微胶囊不能提供任何对 HCl 的保护。有趣的是，在 H(3)PO(4)孵育期间，包封的 LBC-1e 的存活率高于 HCl 胃液。适当选择模拟胃液对于预测益生菌进入人体肠道的输送非常重要。游离或包封的 LBC-1e 都不受胰蛋白酶-胆汁溶液孵育的影响。基于本研究中确定的奶酪中需要提供健康益处的益生菌数量及其在模拟胃消化中的存活情况，理论上应该可以将需要摄入奶酪的量降低到其他发酵乳制品或作为补充剂的 10(3)倍。
