乳清蛋白中性蛋白酶解物对Caco-2细胞铁吸收的影响

Effect of Components of WPC Neutrase Hydrolysates on Iron Uptake by Caco-2 Cells

采用体外消化与Caco-2细胞模型相结合的方法,研究了乳清蛋白浓缩物(WPC)中性酶解产物经超滤后获得的各组分对强化铁生物利用率的影响;采用Sephadex G-25凝胶层析法对WPC的中性酶解产物的消化产物进行分离,并用Caco-2细胞模型评价了分离后各组分对铁吸收的影响。结果表明,WPC中性酶解产物的各组分中,低分子量的组分(分子量小于10 k Da)可以有效提高铁的生物利用率。组分3kR(分子量在3~10 k Da之间)和3k F(分子量小于3 k Da)与铁一起摄入时,铁的生物利用率分别达到23.32%、24.23%,显著高于WPC(2.58%)。铁的吸收率和生物利用率显著相关,而渗透率与生物利用率之间没有显著相关性;WPC中性酶解产物消化产物的各组分中,分子量小于1 k Da的组分将铁的吸收率提高到90.47%,显著高于空白(25.13%)。而分子量为1~5 k Da的一个组分会抑制铁的吸收。

Neutrase hydrolysis of WPC produces hydrolysates that were proved to enhance iron uptake by Caco-2 cells. The objectives of this study were to investigate effects of components of hydrolysates and digestion products of hydrolysates of neutrase-treated WPC on iron uptake. The hydrolysates of WPC treated with neutrase were separated by ultrafiltration. Effect of different components of hydrolysates on iron uptake was studied by in vitro digestion combined with Caco-2 cell model. The results showed that low molecular components( below 10 k Da) enhanced iron bioavailability significantly( p < 0. 05). The components of 3 kR( 3 ~ 10 k Da) and 3k F( below 3 k Da) increased iron bioavailability to 23. 32% and24. 23%,respectively,compared to untreated WPC( 2. 58%). Bioavailability of iron from ferrous sulfate added with different components of the hydrolysates was significantly associated with iron absorption( r = 0. 935,p < 0. 01),while there was no significant relation between iron dialyzability and bioavailability. The hydrolysates of neutrase-treated WPC was digested by pepsin and trypsin gradually to obtain the digestion products,and then separated into four components of different molecular weight by Sephadex G-25. Iron absorption was studied by Caco-2 cells. The results suggested that the components at molecular weight no more than 1 k Da significantly( p < 0. 05) increased iron absorption to 90. 47%compared with 25. 13% in the control,while the components with molecular weight at 1 ~ 5 k Da acted as inhibitor.