混合膳食组成对体外消化过程中GI与食物消解的影响

Effects of Mixed Dietary Constitutes on GI and Food Degradation during In Vitro Digestion

对14种单品食物与8种混合膳食展开了体外消化实验,测定了消化过程中GI的变化过程,研究膳食中不同成分对血糖生成指数的影响,并通过显微镜观察食物在不同消化过程中结构和形貌变化,研究不同成分对食物消解过程的影响。根据食物碳水化合物的含量计算含有50 g碳水化合物的食物量,用50 g葡萄糖作为参照物,利用烧杯或者锥形瓶模拟人体食用食物后在胃部和小肠的4 h消化过程中葡萄糖变化情况。相对于单独的主食来说,加入蔬菜、肉类、蛋类或水果后的混合膳食出现明显的GI下降。研究食物消解过程也发现,混合膳食中米饭的形貌与结构变化会显著慢于单独米饭的外形变化;而挂面的消解趋势与其相反。结果证实了膳食纤维、脂肪和蛋白质会抑制淀粉类食物的消化过程,减缓葡萄糖释放速率。

In vitro digestion experiments were performed on 14 kinds of single-food materials and 8 kinds of mixed dietaries. The changes of GI during the digestion process were experimentally determined to study the effects of different dietary components on the glycemic index. In addition, the structural and morphological changes of food in different digestion processes were monitored microscopically to examine the effects of different components on the degradation. The amount of food containing 50 g carbohydrate was calculated according to the content of carbohydrates in food by using 50 g of glucose as control. Beakers or conical flasks were used to simulate the 4 h digestion process in stomach and small intestine to investigate the glucose changes. Compared to the individual staples, there was a significant GI drop in mixed diet after adding vegetables, meat, eggs or fruits. Furthermore, the results of digestion process also showed that the structural and morphological changes of rice were significantly slower than those of the rice alone, while the tendency of noodle digestion was opposite. The results suggested that dietary fiber, fat and protein would inhibit the digestion of starch food and slow down the release rate of glucose.