六大茶类抑制α–淀粉酶和胰蛋白酶的效果比较

Comparison of inhibitory effects of six kinds of tea on α–amylase and trypsin

以碧香早的一芽二叶为原料,分别加工成绿茶、黄茶、白茶、乌龙茶、黑茶、红茶六大茶类,以蒸青固样制成固定样(对照),通过单因素试验筛选α–淀粉酶和胰蛋白酶的最优反应体系,在最优酶促反应下比较各大茶类对α–淀粉酶和胰蛋白酶的抑制效果。结果表明:通过单因素试验筛选,α–淀粉酶的最适反应浓度为18μg/m L,最适反应时间为20 min,底物、酶、抑制剂的最适添加顺序为先将α–淀粉酶与茶汤置于试管中,在37℃的水浴锅中预热5 min,再加入可溶性淀粉反应;胰蛋白酶的最适反应浓度为0.252 mg/m L,最适反应时间为15 min,底物、酶、抑制剂的最适添加顺序为先将胰蛋白酶与茶汤置于试管中,在40℃的水浴锅中预热5 min,再加入干酪素反应;不同茶类在相同茶汤质量浓度下的抑制效果不同,且在一定范围内均随茶汤质量浓度的增加,对α–淀粉酶、胰蛋白酶的抑制效果增强;在最优酶促反应条件下,对照、绿茶、黄茶、白茶、乌龙茶、黑茶、红茶对α–淀粉酶的抑制率依次为74.1%、74.5%、71.4%、70.4%、70.3%、64.1%、57.3%,其中,绿茶对α–淀粉酶的抑制效果最好,固定样与绿茶、白茶与乌龙茶之间差异不明显,白茶与黄茶、黄茶与乌龙茶之间差异显著(P<0.05),其他茶类之间差异极显著(P<0.01);对照、绿茶、黄茶、白茶、乌龙茶、黑茶、红茶对胰蛋白酶的抑制率分别为86.12%、85.35%、73.11%、68.76%、82.41%、64.76%、56.13%,其中,固定样与绿茶抑制效果较好,两处理的差异不明显,其他茶类之间差异达极显著水平(P<0.01)。

A bud with two leaves of Bixiangzao tea variety in spring as raw material and was separately processed into six categories of tea(green tea,yellow tea,white tea,oolong,brick tea and black tea),the samples fixed by steaming pattern as control to study the inhibitory effects of different kinds of tea onα–amylase and trypsin under the optimal enzymatic reaction conditions(the optimal enzymatic reaction conditions forα–amylase were that 18μg/mLα–amylase and tea infusion were put into test tube and preheat in 37℃water bath for 5 min,and then adding soluble starch to react for 20 min,the optimal enzymatic reaction conditions for trypsin were that 0.252 mg/mL trypsin and tea infusion were put into test tube and preheat in 40℃water bath for 5 min,and then adding casein to react for 15 min).The results showed that with the same concentration of tea infusion,the inhibitory effects of different tea onα–amylase and trypsin were quite different but were all raised with the increase of the tea mass concentration within a certain range.Under the optimal reaction conditions,the inhibitory rate onα–amylase of control group,green tea,yellow tea,white tea,oolong,brick tea and black tea were 74.1%,74.5%,71.4%,70.4%,70.3%,64.1%and 57.3%respectively,showing that the green tea’s inhibitory effect onα–amylase was the best,and there were no significant differences between control group and green tea,white tea and oolong,but remarkable differences between white tea and yellow tea,yellow tea and oolong(P<0.05)and significant differences among the other kinds of tea(P<0.01).While for trypsin,the inhibitory rates of control group,green tea,yellow tea,white tea,oolong,brick tea and black tea were 86.12%,85.35%,73.11%,68.76%,82.41%,64.76%and 56.13%respectively,among which the control group and green tea showed fairly good inhibitory effects and there were significant differences(P<0.01)among the other categories of tea.