In vitro α-glucosidase inhibitory activity of unroasted, and medium, dark and very dark roasted robusta coffee was studied. Coffee extracts significantly inhibited the enzyme activity in a dose-dependent way. The inhibitory activity was well correlated with the degree of roast. Coffee components were separated by gel permeation chromatography into low (1 < MW < 6 kDa), intermediate (15 < MW < 60 kDa) and high (MW > 100 kDa) molecular weight fractions, which were analyzed for the α-glucosidase inhibitory capacity. Only fractions obtained from dark and very dark roasted coffee exhibited inhibitory effect. When the same fraction was obtained from coffee presenting different roasting degree, changes in α-glucosidase inhibition extent were observed. This was attributed to compositional changes within each fraction as induced by roasting. Coffee extracts and their fractions exerted a mixed-type to competitive inhibition against α-glucosidase and these mechanisms are consistent with the complexity of coffee composition.

研究了未经烘焙的，中度，深色和非常深色烘焙的罗布斯塔咖啡的体外α-葡萄糖苷酶抑制活性。咖啡提取物以剂量依赖性方式显着抑制酶活性。抑制活性与烘烤程度密切相关。通过凝胶渗透色谱法将咖啡成分分为低（1 <MW <6 kDa），中等（15 <MW <60 kDa）和高（MW> 100 kDa）分子量级分，分析其对α-葡萄糖苷酶的抑制能力。仅从深色和非常深色的烘焙咖啡中获得的馏分显示出抑制作用。当从具有不同烘焙度的咖啡中获得相同的馏分时，α的变化观察到葡萄糖苷酶抑制程度。这归因于焙烧引起的每个部分内的组成变化。咖啡提取物及其馏分对α-葡萄糖苷酶具有竞争性抑制作用的混合型，这些机制与咖啡组合物的复杂性是一致的。