Vargas Luis A, Olson Douglas W, Aryana Kayanush J
School of Animal Sciences, Louisiana State University Agricultural Center, Baton Rouge 70803.
School of Animal Sciences, Louisiana State University Agricultural Center, Baton Rouge 70803.
J Dairy Sci. 2015 Apr;98(4):2215-21. doi: 10.3168/jds.2014-8869. Epub 2015 Jan 23.
Acid tolerance and bile tolerance are important probiotic characteristics. Whey proteins contain branched-chain amino acids, which play a role in muscle building and are popular among athletes. Increasing emphasis is being placed on diets containing less carbohydrate, less fat, and more protein. The effect of incremental additions of whey protein isolate (WPI) on probiotic characteristics of pure cultures is not known. The objective of this study was to determine the influence of added WPI on acid tolerance and bile tolerance of pure cultures of Streptococcus thermophilus ST-M5 and Lactobacillus bulgaricus LB-12. The WPI was used at 0 (control), 1, 2 and 3% (wt/vol). Assessment of acid tolerance was conducted on pure cultures at 30-min intervals for 2h of acid exposure and bile tolerance at 1-h intervals for 5h of bile exposure. Use of 1, 2, and 3% WPI improved acid tolerance of Strep. thermophilus ST-M5 and Lb. bulgaricus LB-12. The highest counts for acid tolerance of Strep. thermophilus ST-M5 and Lb. bulgaricus LB-12 were obtained when 3% WPI was used. Use of 2 and 3% WPI improved bile tolerance of Strep. thermophilus ST-M5 and Lb. bulgaricus LB-12 over 5h of bile exposure. The use of WPI is recommended to improve acid and bile tolerance of the yogurt culture bacteria Strep. thermophilus ST-M5 and Lb. bulgaricus LB-12.
耐酸性和耐胆汁性是重要的益生菌特性。乳清蛋白含有支链氨基酸，对肌肉发育有作用，在运动员中很受欢迎。人们越来越重视碳水化合物含量更低、脂肪含量更低且蛋白质含量更高的饮食。乳清分离蛋白（WPI）增量添加对纯培养物中益生菌特性的影响尚不清楚。本研究的目的是确定添加WPI对嗜热链球菌ST-M5和保加利亚乳杆菌LB-12纯培养物的耐酸性和耐胆汁性的影响。WPI的使用浓度为0（对照）、1%、2%和3%（重量/体积）。对纯培养物进行耐酸性评估，在酸暴露2小时期间每隔30分钟进行一次，对耐胆汁性评估，在胆汁暴露5小时期间每隔1小时进行一次。使用1%、2%和3%的WPI可提高嗜热链球菌ST-M5和保加利亚乳杆菌LB-12的耐酸性。当使用3%的WPI时，嗜热链球菌ST-M5和保加利亚乳杆菌LB-12的耐酸性计数最高。在胆汁暴露5小时期间，使用2%和3%的WPI可提高嗜热链球菌ST-M5和保加利亚乳杆菌LB-12的耐胆汁性。建议使用WPI来提高酸奶培养菌嗜热链球菌ST-M5和保加利亚乳杆菌LB-12的耐酸性和耐胆汁性。
