植酸及几种酚酸对牛奶蛋白体外消化率的影响

Effects of Phytic Acid and Phenolic Compounds on the in vitro Digestibility of Milk Proteins

研究植酸和几种酚类物质(阿魏酸、单宁、水杨酸、对-羟基苯甲酸)在常温和灭菌条件下(121℃,20min)对牛奶蛋白体外消化率的影响。结果表明:植酸和4种酚类物质均降低蛋白质消化率,降幅为5%～27%;反应后延长静置时间可进一步降低蛋白质消化率;增加胃蛋白酶浓度可使蛋白体外消化率提高1%～9%。

Pure milk samples with separately added phytic acid and phenolic compounds such as ferulic acid,tannin,salicylic acid and p-hydroxybenzoic acid at different levels were subjected to standing at normal temperature for 1 h or sterilization at 121 ℃ for 20 min followed by cooling to the normal temperature prior to pepsin hydrolysis in order to investigate the effects of phytic acid these phenolic compounds on the in vitro digestibility of milk proteins.The results indicated that all these compounds added alone resulted in a decrease in digestibility of milk proteins by 5%-27%.Prolonged length of standing time after cooling to the normal temperature（in the case of milk samples subjected to sterilization） resulted in a higher protein digestibility.Moreover,with increasing pepsin concentration,protein digestibility in vitro increase by 1%-9%.