Van Soest P J
Am J Clin Nutr. 1978 Oct;31(10 Suppl):S12-S20. doi: 10.1093/ajcn/31.10.S12.
Fiber is a variable material with respect to its nutritional qualities depending upon its composition and physical properties. Biological properties possessed by one type of fiber might not be shared by another type. Separate methods are required to describe quantity, composition, and quality of fiber in foods. Fibers can be generally classified into three groups: vegetable fibers, which are highly fermentable with low indigestible residue; brans, which are less fermentable; and chemically purified fibers such as wood cellulose, which are relatively unfermentable. A class of soluble substances including pectins and gums may not be true fibers, but are considered part of the dietary fiber complex because of the similar effects they can elicit in the diet. A major need is the replacement of the crude fiber method, the present official method, which is seriously defective. Since crude fiber values are erratic and poorly related to the true fiber value of food, a second major need is the reanalysis of all foodstuffs by appropriate methods and the replacement of standard tables of food composition. Accomplishment of these purposes will require more support and promotion than is presently being received.
就其营养品质而言，纤维是一种可变的物质，这取决于其组成和物理特性。一种纤维所具有的生物学特性可能不为另一种纤维所共有。需要用不同的方法来描述食物中纤维的数量、组成和质量。纤维通常可分为三类：植物纤维，具有高度可发酵性且难消化残渣少；麸皮，可发酵性较差；以及化学纯化纤维，如木质纤维素，相对不可发酵。一类包括果胶和树胶的可溶性物质可能并非真正的纤维，但由于它们在饮食中能产生类似的作用，所以被视为膳食纤维复合物的一部分。一个主要需求是取代目前存在严重缺陷的官方粗纤维方法。由于粗纤维值不稳定且与食物的真实纤维值相关性差，另一个主要需求是用适当的方法对所有食品进行重新分析，并取代食物成分标准表。要实现这些目标，需要比目前所得到的更多的支持和推广。
