The objective of this study was to characterize physical and microbiological properties of powders prepared by mixing Lactobacillus salivarius NRRL B-30514 suspensions with skim milk powder (SMP), spray-dried lactose (SDL), milk protein concentrate (MPC), or MPC/SDL at a mass ratio of 1:2, 1:1 or 2:1 to understand the relative significance of proteins and lactose in bacterial survival. The probiotic viability and storage stability were significantly improved with the increase of dairy protein content. Based on water sorption isotherms and X-ray diffraction spectroscopy, MPC was suggested to preferentially absorb water in cell suspensions, which inhibited the hydration of SDL and therefore lowered the hypertonic pressure to the adhered cells. The LIVE/DEAD® BacLight™ and CTC reduction assays detected higher membrane integrity and respiratory activity of bacteria for treatments with more proteins. Findings from the current study indicated the more significant role of milk proteins than lactose protecting bacteria during dehydration.

这项研究的目的是表征通过将唾液乳杆菌NRRL B-30514悬浮液与脱脂奶粉（SMP），喷雾干燥乳糖（SDL），浓缩乳蛋白（MPC）或MPC /混合而制备的粉末的物理和微生物特性SDL以1：2、1：1或2：1的质量比了解蛋白质和乳糖在细菌存活中的相对重要性。随着乳蛋白含量的增加，益生菌的活力和储存稳定性得到了显着提高。基于吸水等温线和X射线衍射光谱，建议MPC优先吸收细胞悬浮液中的水，这抑制了SDL的水合作用，从而降低了对粘附细胞的高渗压力。直播/DEAD®北Light™和CTC减少检测可检测到更高的膜完整性和细菌呼吸活性，从而可以用更多的蛋白质进行处理。当前研究的结果表明，在脱水过程中，乳蛋白比乳糖保护细菌更重要。