海藻酸钠和乳清蛋白作为益生菌包埋壁材的比较

利用海藻酸钠和乳清蛋白分别制备包埋有两歧双歧杆菌的微胶囊，测定了不同微胶囊的粒径、包埋效率、缓冲能力和外观形态，同时还考察了不同微胶囊对两歧双歧杆菌保护效果的影响。结果表明：乳清蛋白微胶囊的粒径和包埋效率均要高于海藻酸钠微胶囊，分别为202.5 μm，87.8%和118.3 μm，48.1%；虽然在高胆盐环境中两种微胶囊对两歧双歧杆菌的保护效果没有显著差别，但在低酸环境、模拟胃液和常温贮藏期中，相比于海藻酸钠微胶囊，乳清蛋白微胶囊将两歧双歧杆菌的存活量分别提高了大约5、2、0.5（lg（CFU/mL））。乳清蛋白微胶囊在pH值偏中性的环境中具有较高的缓冲能力；在外观形态上，由高浓度乳清蛋白溶液制备而来的微胶囊具有较好的呈球性和致密度，这些可能是乳清蛋白微胶囊具有较高保护效果的原因。

Comparison of Alginate and Whey Protein as Two Different Coating Materials Used for Probiotic Microencapsulation

Two different microcapsules containing Bifidobacterium bifidum were individually prepared using alginate and
whey protein. Their characteristics, including particle size, microencapsulation yield, micrographs, buffering capacity and
protective effect on microencapsulated cells, were studied. The results showed that the particle size and microencapsulation
yield of whey protein microcapsules (202.5 μm, 87.8%) were both higher than those of alginate microcapsules (118.3 μm,
48.1%). At high concentration of bile salt solution, there was no significant difference in protective effect on
microencapsulated Bifidobacterium bifidum between these two microcapsules. However, the whey protein microcapsules provided
a better protection for microencapsulated Bifidobacterium bifidum than alginate microcapsules did when treated with acid
condition, simulated gastric juice and ambient storage condition, and the survival count of microencapsulated Bifidobacterium
bifidum in whey protein microcapsules was 5, 2, and 0.5 (lg (CFU/mL)) higher than that in alginate microcapsules, respectively.
There may be two reasons for this better protection: first, whey protein has higher buffering capacity at nearly neutral pH; and
second, whey protein microcapsules have better micrographs in terms of sphericity and density.