Dietary fiber

Abstract

In the first edition of Handbook of Food Analysis the chapter on dietary fiber provided a comprehensive summary of over 40 methods, creating a record of the development of fiber analysis (1). In this revised chapter the focus is much more on methods currently in use and those appropriate for the analysis of human foods. The reader may refer to the first edition for details of the methods that are of particular interest. Since the first edition there has been continued debate on the definition of dietary fiber and, linked to definition, the most appropriate methods for fiber analysis (2,3). A real attempt has been made to arrive at a single definition and method of analysis through international consultation. However, universal acceptance has not been reached. At least for regulatory and food labeling purposes, for which most dietary fiber analysis is required, there is, for the present time, a general acceptance of certified AOAC (Association of Official Analytical Chemists) International methods. In this chapter, as the focus is on methods that are suitable for analyzing human foods, methods that were discussed in the first edition but are regarded as more suitable for ruminant feeds than for human foods, such as the neutral detergent method (4), will not b discussed. Of recent reviews of the current state of dietary fiber analysis, that of Cho et al. gives detailed instructions on the AOAC methods (5). Brief overviews have been given by Asp (6) and McLeary (7). The report recently released by the Panel on the Definition of Dietary Fiber, Standing Committee on the Scientific Evaluation of Dietary Reference Intakes, Institute of Medicine (U.S.A.), gives an excellent overview (3).