茶多酚对淀粉消化酶动力学的影响
Effect of tea polyphenols on starch digestive enzymes kinetics
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摘要: 研究茶多酚对淀粉酶动力学以及对淀粉体外消化的影响,结果表明,茶多酚对猪胰α-淀粉酶的抑制作用属于非竞争性抑制,对淀粉葡萄糖苷酶具有明显的促进作用;在茶多酚浓度低于20%（茶多酚/淀粉）时,对Englyst法混酶体系起抑制作用,最大抑制率可达30%,浓度超过20%时,对混酶反而起促进作用,最大促进率为20%;选取两个浓度研究茶多酚对普通玉米淀粉体外消化的影响,添加10%茶多酚（茶多酚/淀粉）抑制普通玉米淀粉的消化,25%茶多酚（茶多酚/淀粉）促进普通玉米淀粉的消化,证明茶多酚对淀粉消化性体外测定方法的准确性存在影响。Abstract: The effect of tea polyphenols (TPLs) on the activities of starch digestive enzymes and on the in vitro digestion of starch were investigated.Results showed that TPLs noncompetitively inhibited the activity of pancreaticα-amylase but activated fungal amyloglucosidase (AMG) evidently.When a dual enzyme reaction system containing bothα-amylase and AMG was employed to study the effect of TPLs on starch digestion, a skewed bell shaped inhibition pattern was shown with a peak inhibition of 30%when the content of TPL was 20% (starch-based, w/w) , but a negative inhibition was observed when the content of TPLs was greater than 20%.Consistently, a higher degree of starch digestion in the presence of 25%TPLs and a lower degree of digestion in the presence of 10%TPLs demonstrated the heterogeneous effect of TPLs on the digestion of starch.Therefore, tea polyphenols had effect on accuracy of method for in vitro determination of the digestibility of starch.
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