Study On The Effect Of Tea Polyphenols On The Digestion And Absorption Of Casein In Vitro And In Vivo

The effects of bovine casein protein and epigallocatechin gallate(EGCG)binding on the simulated digestibility of casein were analyzed by SDS-PAGE and in vitro digested digestive phase.The establishment of nutritional deficiency model in mice and the effect of tea polyphenols on the nutritional supplementation of casein in mice were also studied.The experimental results are as follows:1)SDS-PAGE analysis showed that casein binds to EGCG.The protein subunit with a molecular weight of 27.6kDa of casein is greatly affected by EGCG.The protein subunit will gradually decrease or even disappear with the increase of EGCG concentration;2)In the simulated experiment of binding of EGCG to casein in vitro,the particle size of casein solution with the same concentration of EGCG increased gradually at each digestive stage,and the absolute Zeta potential was higher than that of casein solution without EGCG,indicating that EGCG inhibited the digestion of casein;3)The effect of EGCG on casein hydrolysis was studied.Trypsin partially hydrolyzed casein and determined the amino acids in the hydrolysate.The level of amino acid(lysine,histidine,phenylalanine)in casein hydrolysate was decreased by EGCG addition,and inhibition effects on casein hydrolysis were correspondingly enhanced with the increase of EGCG contents added;4)The body weight analysis indicated that EGCG did not affect the body weights,main organs’ weights of malnourished mice which received the normal protein diet;and had no significant effects on the body fat ratio of mice;5)The biochemical analysis showed that EGCG can significantly decrease the levels of serum creatinine,serum total cholesterol,total triglycerides,total protein and hepatic total protein;After the normal protein diet’s recovery for malnourished mice,the serum levels of alanine transaminase(ALT)and aspartate transaminase(AST）were increased,but EGCG can significantly decreased their increase;...