Snow P, O'Dea K
Am J Clin Nutr. 1981 Dec;34(12):2721-7. doi: 10.1093/ajcn/34.12.2721.
After accurate determination of the content of available carbohydrate in a wide variety of cereals, as in vitro method was used to study factors that influence hydrolysis rates of starch in foods. Fiber, physical form, cooking, and the possible presence of a natural amylase inhibitor were all shown to affect hydrolysis rates of starch. Fiber only exerted an inhibiting effect on the rate of hydrolysis when it formed a physical barrier to limit access of the hydrolytic enzymes to the starch (as in whole brown rice, for example). Particle size played an important role in determining the rate of hydrolysis. Cooking made the starch much more readily available for enzymic hydrolysis presumably by gelatinizing it. Stoneground wholemeal flour was hydrolyzed more slowly than white flour. This is consistent with the presence of a natural amylase inhibitor that has been isolated from wheat germ in the whole grain. Our results suggest that such amylase inhibitor activity is destroyed by passage through the roller mill, since the starch in wheat germ and standard wholemeal flour (i.e., not stoneground but reconstituted after passage through the roller mill) was hydrolyzed at a rate identical to white flour.
在准确测定了多种谷物中可利用碳水化合物的含量后，采用体外方法研究影响食物中淀粉水解速率的因素。结果表明，纤维、物理形态、烹饪方式以及天然淀粉酶抑制剂的可能存在都会影响淀粉的水解速率。只有当纤维形成物理屏障限制水解酶与淀粉接触时（例如在全糙米中），才会对水解速率产生抑制作用。颗粒大小在决定水解速率方面起着重要作用。烹饪可能通过使淀粉糊化，使其更易于酶解。石磨全麦粉的水解速度比白面粉慢。这与从全谷物小麦胚芽中分离出的天然淀粉酶抑制剂的存在相一致。我们的结果表明，这种淀粉酶抑制剂的活性在经过辊磨机后被破坏，因为小麦胚芽和标准全麦粉（即不是石磨的，而是经过辊磨机后重新组成的）中的淀粉水解速率与白面粉相同。
