干酪乳杆菌/乳糖醇双层合生元微胶囊制备及其在橙汁中的应用

目的:利用酶促法制备干酪乳杆菌/乳糖醇合生元微胶囊,研究乳糖醇浓度对微胶囊特性的影响,并对制备的微胶囊开展应用研究。方法:以黏玉米来源谷氨酰胺转氨酶(TGZ)为催化剂,以酪蛋白和海藻酸钠为壁材,通过内源乳化法对合生元进行双层包埋。利用粒径和干酪乳杆菌在模拟胃肠液中的存活率为指标,确定乳糖醇的添加量,并对其进行形态学观察。最后将制备的微胶囊添加到橙汁饮料中,评价干酪乳杆菌在低温贮藏时的存活情况。结果:TGZ可以交联酪蛋白对干酪乳杆菌/乳糖醇合生元进行包埋。当乳糖醇添加量为1.0 g/100 mL时,双层包埋的微胶囊粒径最小,包埋率最大为61.73%。在模拟胃肠液实验中,添加1.0 g/100 mL的乳糖醇可以提高干酪乳杆菌的存活率。扫描电镜结果表明,干酪乳杆菌完全包裹在壁材中,表明微胶囊的抗穿透物理屏障对益生菌的保护作用。贮存试验发现,添加乳糖醇后橙汁中的活菌数比未添加乳糖醇的高0.56个对数值。结论:双层微胶囊对乳酸菌的存活有很好的保护作用,且乳糖醇的存在也可以提高益生菌的存活率,因此益生菌/乳糖醇合生元微胶囊在食品,尤其是功能性食品方面具有广阔的应用前景。

Preparation of Lactobacillus casei / Lactitol Synbiotic Microcapsule and Its Application in Orange Juice

Objective:The microcapsules of synbiotic Lactobacillus casei/lactitol were prepared by enzymatic method.The effect of lactitol concentration on the microcapsules characteristic was studied,and the application of the microcapsules was assessed.Method:Synbiotic L.casei/lactitol was microencapsulated in casein using internal emulsion technique with Zea mays transglutaminase(TGZ)induced gelation and alginate coating.The particle size of microcapsules and the survivability of L.casei in casein beads coated with alginate in simulated gastrointestinal conditions were studied to determine the amount of lactitol.Moreover,the morphology of microcapsules was observed by scanning electron microscope(SEM).Finally,prepared microcapsules were added into orange juice to evaluate the survival of L.casei in low temperature storage.Result:TGZ could used as an enzyme to cross-link casein to encapsulated L.casei/lactitol.The small particle size and high encapsulation efficiency(61.73%)achieved with the addition of 1.0 g/100 mL lactitol.In simulated gastrointestinal tests,the survivability of L.casei was improved by 1.0 g/100 mL lactitol.Result from SEM observations showed complete encapsulation of probiotic cells in the wall materials,suggesting that the protection was provided by the strong penetration-resistant physical barriers of the microcapsules.The storage experiment indicated that the number of cells with lactitol were higher than those of without lactitol by 0.56 logarithmic number.Conclusion:The double-layer microcapsule has a very good protective effect on the survival of Lactobacillus,and the existence of lactitol can also improve the survival rate of probiotics,so probiotics/lactitol synbiotics microcapsules have a broad application in food,especially in functional food.