Limosilactobacillus reuteri was encapsulated using Maillard-reaction-products (MRPs) of soy protein isolate (SPI) and α-lactose monohydrate by freeze-drying. The mixed solution of SPI and α-lactose monohydrate was placed in a water bath at 89°C for 160 min for Maillard reaction, and then freeze-dried to obtain MRPs. The effects of Maillard reaction on functional characteristics of MRPs and the properties of MRPs-microcapsules were studied. SDS-PAGE indicated that SPI subunit reacted with lactose to form a polymer, and the band of MRPs disappeared around the molecular weights of 33, 40, 63, and 100 kDa. Compared with SPI, the emulsion stability, emulsion activity, foaming capacity, foam stability, and gel strength of MRPs were increased by 259%, 55.71%, 82.32%, 58.53%, and 3266%, respectively. The results of Fourier transform infrared spectroscopy, circular dichroism spectroscopy, and scanning electron micrographs confirmed that the protein structure also changed significantly. Then, MRPs were used as wall material to prepare L. reuteri microcapsules. Physical properties and viable counts of L. reuteri during the simulated gastrointestinal digestion and storage period were determined. The particle size of MRPs-microcapsules (68 μm) was smaller than that of SPI-microcapsules (91 μm). The viable counts of L. reuteri in simulated gastrointestinal digestion and after storage for 30 days were improved. The modifications with Maillard reaction can improve emulsification, foaming, and gel strength of SPI, and MRPs could be used as a new type of wall material in the production of L. reuteri microcapsules.

罗伊氏乳酸杆菌使用大豆分离蛋白 (SPI) 和 α-乳糖一水合物的美拉德反应产物 (MRP) 通过冷冻干燥封装。将SPI和α-乳糖一水合物的混合溶液置于89℃水浴中160分钟进行美拉德反应，然后冷冻干燥得到MRPs。研究了美拉德反应对MRPs功能特性和MRPs-微胶囊性质的影响。SDS-PAGE表明SPI亚基与乳糖反应形成聚合物，MRPs带在分子量33、40、63和100 kDa附近消失。与SPI相比，MRPs的乳液稳定性、乳液活性、发泡能力、泡沫稳定性和凝胶强度分别提高了259%、55.71%、82.32%、58.53%和3266%。傅里叶变换红外光谱结果，圆二色光谱和扫描电子显微照片证实蛋白质结构也发生了显着变化。然后，MRPs 被用作壁材料来制备罗伊氏乳杆菌微胶囊。确定了模拟胃肠道消化和储存期间罗伊氏乳杆菌的物理特性和活菌数。MRPs-微胶囊（68μm）的粒径小于SPI-微胶囊（91μm）的粒径。模拟胃肠道消化和储存 30 天后罗伊氏乳杆菌的活菌数得到改善。美拉德反应改性可提高SPI的乳化、发泡和凝胶强度，MRPs可作为罗伊氏乳杆菌微胶囊生产的新型壁材。