Food Science Program, Division of Food Systems and Bioengineering, University of Missouri, Columbia, MO, USA.
Food Microbiol. 2012 May;30(1):68-73. doi: 10.1016/j.fm.2011.10.017. Epub 2011 Nov 18.
Soy oligosaccharides, mainly α-galactosides, are prevalently present in soy protein products, and can result in unfavorable digestive effects when consumed. The aim of this research was to investigate the efficiency of α-galactoside reduction by probiotic bacterial hydrolysis and if such bacteria could be maintained in a high number in a soy protein product in a microencapsulated and freeze-dried form. The probiotic bacterium, Lactobacillus acidophilus LA-2, when induced by raffinose, exhibited a high level of α-galactosidase activity at 5.0 U/mg. To preserve probiotics with high viability, cells were microencapsulated and freeze-dried. Optimization of microencapsulation presented that a combination of κ-carrageenan and inulin at a proportion of 1.9:0.1 (w:w) as capsule wall materials, significantly retained the viability of the probiotics through freeze-drying (P ≤ 0.05). Scanning electron microscopic images confirmed that the morphology of the microcapsules was well preserved after freeze-drying. Upon incorporation into soy protein bars, the freeze-dried microcapsules of L. acidophilus LA-2 remained in high numbers throughout 14 weeks of storage at 4 °C. Results of this work with the support of other studies on microencapsulation benefits indicate a promising use of freeze-dried α-galactosidase positive microencapsulated probiotics in a soy food.
大豆低聚糖主要是α-半乳糖苷，普遍存在于大豆蛋白产品中，当被食用时会产生不利的消化作用。本研究旨在探讨益生菌细菌水解降低α-半乳糖苷的效率，以及这种细菌是否可以以微囊化和冷冻干燥的形式在大豆蛋白产品中保持高数量。在棉子糖的诱导下，益生菌嗜酸乳杆菌 LA-2 表现出高水平的α-半乳糖苷酶活性，为 5.0 U/mg。为了保持益生菌的高存活率，细胞被微囊化和冷冻干燥。微囊化的优化表明，κ-卡拉胶和菊粉以 1.9:0.1（w:w）的比例作为胶囊壁材料的组合，通过冷冻干燥显著保留了益生菌的存活率（P≤0.05）。扫描电子显微镜图像证实，微胶囊的形态在冷冻干燥后得到了很好的保存。将冷冻干燥的嗜酸乳杆菌 LA-2 微胶囊掺入大豆蛋白棒中，在 4°C 下储存 14 周，其数量仍保持在较高水平。这项工作的结果以及其他关于微囊化益处的研究表明，冷冻干燥的α-半乳糖苷阳性微囊化益生菌在大豆食品中有很好的应用前景。
