乳清蛋白磷酸化改性对其营养价值和消化吸收的影响  

The Effect of Phosphorylation on Nutritional Value and Nutritional Quality of Whey Protein

作　　者：李金华 李博[1] 王成涛[2] Li Jinhua;Li Bo;Wang Chengtao(College of Food Science and Nutritional Engineering,China Agricultural University,Beijing 100086;Beijing Laboratory for Food Quality and Safety,Beijing Technology and Business University,Beijing 100048)

机构地区：[1]中国农业大学食品科学与营养工程学院,北京100083 [2]北京工商大学食品质量与安全北京实验室,北京100048

出　　处：《中国食品学报》2020年第5期19-28,共10页Journal of Chinese Institute Of Food Science and Technology

摘　　要：目的:探究磷酸化改性对乳清分离蛋白(WPI)营养价值和消化吸收的影响。方法:利用三聚磷酸钠(STP)对WPI进行磷酸化改性,比较改性前、后的乳化性及乳化稳定性、起泡性及泡沫稳定性和凝胶硬度以及氨基酸组成,采用体外模拟消化模型和Caco-2细胞吸收模型进行体外模拟消化吸收试验,测定并比较改性前、后WPI的消化吸收率及氨基酸组成。结果:STP添加量从1%增至7%时,改性程度随添加量的增加而增大,WPI的功能性质显著提高(P﹤0.05);WPI中苏氨酸(Thr)和赖氨酸(Lys)的氨基酸评分(AAS)随着改性程度的增大而减小,各改性组的氨基酸比值系数分(SRCAA)无明显差别;磷酸化改性前、后WPI的消化吸收率无显著差异(P﹥0.05)。对比磷酸化改性前、后WPI的氨基酸组成,结果谷氨酸(谷氨酰胺)含量显著降低(P﹤0.05),推测谷氨酰胺可能是除赖氨酸之外的磷酸化位点。结论:WPI磷酸化改性在改善其功能性质的同时,不影响蛋白质的营养价值和消化利用。Objective:To investigate the effect of phosphorylation on nutritional value and digestion and absorption of whey protein isolate(WPI).Methods:Phosphorylation of WPI by sodium tripolyphosphate(STP)was carried out.The emulsifying and emulsifying stability,foaming and foam stability,gel hardness and amino acid composition before and after modification were compared.In vitro simulated digestion model and Caco-2 cell absorption model were used to simulate digestion and absorption experiments.The digestion and absorption rate and amino acid composition of WPI before and after modification were determined and compared.Results:When the content of STP increased from 1%to 7%,the degree of modification increased with the increase of the amount of addition,and the functional properties of WPI increased significantly(P<0.05).Threonine(Thr)and lysine(Lys)decreased with the increase of the degree of modification,but there was no significant difference in SRCAA among the modified groups.The digestion and absorption rate of WPI before and after phosphorylation modification was not significant difference(P>0.05).Comparing the amino acid composition of WPI before and after phosphorylation modification,glutamic acid(glutamine)content was significantly decreased(P<0.05),suggesting that glutamine may be a phosphorylation site other than lysine.Conclusion:Phosphorylation of WPI improve the functional properties of the same time,does not affect the nutritional value of protein and digestion and utilization.

关 键 词：乳清分离蛋白 磷酸化 营养价值 消化吸收 

分 类 号：TS201.2[轻工技术与工程—食品科学]