To reduce the rate of oxidative rancidity of unsaturated fatty acid and improve digestion and absorption of nutritional oils for infant formula,nano-emulsion was obtained using the whey protein as wall material and the blend oil as oil phase via ultrasonic method.The microencapsulated blend oil from the nano-emulsion was prepared by spray-drying.On the basis of single factor test,response surface methodology was established using the particle size of emulsion as dependent variable,while emulsifier dosage,ultrasonic power and treatment time were used as independent variable.Results showed that the optimum conditions of preparation were as follow:emulsifier dosage mass fraction 5.0％ (w/w,the total mass of solids),ultrasonic power 660 W,and ultrasonic time 20 min,the average particle size of emulsion was (184.37 ± 0.64) nm and the surface oil content of products was 5.82％.On this basis,response surface model data could effectively guide the operation of this test.Product quality was good upon dry spraying,and the release amount of free fatty acids of nanoemulsion was higher than that in untreated blend oil during fasting and feeding based on an in vitro digestion method.%为了降低婴儿配方营养油中不饱和脂肪酸的氧化酸败和提高其消化吸收,该研究以调和油为油相、乳清蛋白为壁材,将乳化剂溶于油相,超声法制备成纳米级乳化液,利用喷雾干燥法将纳米乳液制备成微胶囊粉末.以乳液粒径为响应值,用响应面分析法研究乳化剂添加量、超声功率和超声时间等因素对乳液粒径和喷雾干燥产品表面含油率的影响,优化制备工艺.结果表明,最佳工艺条件为:卵磷脂(PC)质量分数5.0％、超声功率660 W和超声时间20 min,乳液的平均粒径为(184.37±0.64) nm,微胶囊表面含油率为5.82％,依据此响应面模型数据可有效指导试验操作.喷雾干燥后的产品品质较好,在体外消化模拟试验中,在禁食和喂食状态下纳米乳液的游离脂肪酸释放量均高于未处理调和油.
展开▼
