Effect of Green Tea Catechins on the Postprandial Glycemic Response to Starches Differing in Amylose Content
Effect of Green Tea Catechins on the Postprandial Glycemic Response to Starches Differing in Amylose Content
复制标题
绿茶儿茶素对不同直链淀粉含量淀粉的餐后血糖反应的影响
DOI：
10.1021/jf200355q
复制
发表时间：
2011-05-11
影响因子：
6.1
通讯作者：
Zhang, Genyi
中科院分区：
文献类型：
--
作者：
Liu, Jie;Wang, Mingzhu;Zhang, Genyi
研究了茶多酚(TPLs)，特别是茶儿茶素对不同淀粉酶含量的熟淀粉餐后血糖反应的影响。用小鼠模型进行的体内实验表明，普通淀粉(含27.8%淀粉)或糯玉米淀粉与10%(淀粉干重)共煮可适度降低餐后血糖反应，而以高淀粉酶玉米淀粉(MAC，含79.4%淀粉酶)为淀粉组分时，血糖反应增强，血糖峰值延迟。酶动力学结果表明，TPLs对糯质或普通玉米淀粉的消化有非竞争性抑制作用，而对MAC淀粉的消化速率在TPLs的存在下增加，这支持了观察到的餐后血糖反应。进一步的X射线粉末衍射研究表明，普通淀粉和HAc淀粉的衍射强度(衍射线下面积)分别提高了45%和74%，而糯玉米淀粉的衍射强度没有变化。使用纯淀粉酶溶液的动态激光光散射研究一致地表明，在TPLs的存在下，淀粉酶分子的流体动力学半径从类似54 nm增加到类似112 nm。这些实验结果表明，TPLs和淀粉酶之间可能存在相互作用，这种相互作用促进了淀粉酶分子之间的结合，形成了一种特殊的无序结构，可以产生高而持续的餐后血糖反应。因此，茶多酚和特定淀粉的组合可以用来操纵餐后血糖反应，以控制血糖和最佳健康。
The effect of tea polyphenols (TPLs), specifically tea catechins, on the postprandial glycemic response to cooked starches differing in amylase contents was investigated. The in vivo test using a mouse model showed a moderate reduction of the postprandial glycemic response to co-cooked normal (containing 27.8% amylase) or waxy corn starch with 10% TPLs (dry weight of starch), while an augmented glycemic response with a delayed blood glucose peak was observed when high amylase corn starch (MAC, containing 79.4% amylase) was used as the starch component. Enzyme kinetics results demonstrated that TPLs noncompetitively inhibit the digestion of waxy or normal corn starch, while the digestion rate of MAC starch was increased in the presence of TPLs, which supports the observed postprandial glycemic responses. Further studies using X-ray powder diffraction showed that the diffraction intensity (area under the diffraction curves) of normal and HAC starch was increased by 45% and 74%, respectively, whereas no change was observed for waxy corn starch. Consistently, dynamic laser light scattering studies using a solution of pure amylase showed an increased hydrodynamic radius of amylase molecules from similar to 54 nm to similar to 112 nm in the presence of TPLs. These experimental results indicate that there might exist an interaction between TPLs and amylase, which facilitates the association of amylase molecules to form a special nonordered structure that can produce a high and sustained postprandial glycemic response. Thus, a combination of tea polyphenols and specific starches could be used to manipulate postprandial glycemic response for glycemic control and optimal health.