Effect of Cooking on the Content of Dietary Fiber in Vegetables, Method for Determination of Dietary Fiber in Vegetables, and Physiological Function of Dietary Fiber in Vegetables

采用Prosky法和改进Prosky法研究了蒸煮对14种蔬菜中膳食纤维含量的影响，并对两种方法测定的膳食纤维含量进行了比较。改良Prosky法在不减去酶消化残渣中粗蛋白质（氮*6.25）的情况下测定饲粮纤维值。此外，对粗蛋白质含量较高的6种蔬菜进行了酶消化渣中真蛋白质含量的测定。除牛蒡和黄瓜外，可溶性纤维酶解渣粗蛋白质含量为200 ~ 500mg/g，不溶性纤维酶解渣粗蛋白质含量为50 ~ 260mg/g。水煮和油炸对可溶性和不溶性膳食纤维含量有增加、减少或不变的影响。这些变化各不相同。可溶性纤维中真蛋白质含量为粗蛋白质的lO-19%，不可溶性纤维中真蛋白质含量为31-36%。由此可见，在可溶性纤维中，Prosky法与改良Prosky法测定的纤维含量差异极小，除牛蒡外，新鲜蔬菜中可溶性纤维含量均小于1g/ g鲜重。但两种方法测定的不溶性纤维含量差异对含纤维量较大的品种的纤维含量影响较大。牛蒡的纤维含量约为鲜重的10%，在蔬菜中含量最高，但其含量随农作季节和品种变化较大。食用牛蒡或竹笋餐的妇女的生热率比不含牛蒡或竹笋餐的妇女高2-4%。

The effects of cooking on the contents of dietary fiber in 14 kinds of vegetable were studied using Prosky method and the modified Prosky method, and the contents of dietary fiber measured by both methods were compared to each other. In the modified Prosky method, dietary fiber values were determined without subtraction of crude protein(nitrogen*6.25) in enzyme digested residue. In addition, the contents of true protein in enzyme digested residue were estimated in six kinds of vegetables which contained more crude protein.The contents of crude protein in enzyme digested residue were 200-500mg/g of enzyme digested residue in soluble fiber except bur-dock and cucumber, and 50-260mg/g in insoluble fiber. The contents of soluble and insoluble dietary fiber were increased, decreased or not changed with boiling or frying. The changes were different from each other. The amounts of true protein were lO-19% of crude protein in soluble fiber and 31-36% in insoluble fiber. This result suggests that in soluble fiber the difference of fiber contents measured by both Prosky method and the modified Prosky method was extremely small since the contents of soluble fiber in fresh vegetables were less than 1g/lOOg of fresh weight except bur-dock. But the difference of insoluble fiber contents measured by both methods influenced significantly the content of fiber in the kinds containing much amount of fiber.The fiber content of bur-dock was about 10 % of fresh weight, the largest value in those of vegetables, but the content seemed to vary with farming season and kinds very much.The diet induced thermogenesis in the women taking the bur-dock or bamboo shoots containing meal was 2-4% more than the bur-dock or bamboo shoots free meal.