Dietary fibers definition

Historically, dietary fiber referred to iasoluble plant cell wall material, primarily polysaccharides, not digested by the endogenous enzymes of the human digestive tract. This definition has been extended to iaclude other nondigestible polysaccharides, from plants and other sources, that are iacorporated iato processed foods. Cellulose [9004-34-6] (qv) is fibrous however, lignin [9005-53-2] (qv) and many other polysaccharides ia food do not have fiberlike stmctures (see also Carbohydrates). 

Trowell H. 1976. Definition of dietary fiber and hypotheses that it is a protective factor in certain diseases. Am J Clin Nutt 29 417 127. 

Wheat bran has been the fiber source most commonly used to study effects of dietary fiber on calcium absorption in controlled laboratory studies. However, wheat bran and other forms of fiber as they occur in food products present several disadvantages in terms of definition and by concurrently altering intakes of other substances or materials known or suspected of having an adverse effect on the bioavailability of calcium such as phytates and oxalates (5,13,17,22-28). Several studies have been conducted which have sought to separate or compare the effects of phytate and fiber... 

Definition Mainly cell wall polysaccharides and the principal component of dietary fiber. 

Bingham, S. (1987). Definitions and intakes of dietary fiber. Am. f. Clin. Nutr. 45,1226-1231. Calloway, D. H. (1966). Respiratory hydrogen and methane as affected by consumption of gas-forming foods. Gastroenterology 51,383-389. 

Institute of Medicine. Proposed definition of dietary fiber. A report of the panel on the definition of dietary fiber and the standing committee on the scientific evaluation of dietary reference intakes, food and nutrition board National Academies Press Washington, DC, 2001. 

American Association of Cereal Chemists Report, The definition of dietary fiber. Cereal Foods World,... 

The widely accepted definition of dietary fiber as proposed by Trowell (1) refers to "plant polysaccharides and lignin which are resistant to hydrolysis by digestive enzymes of man" as the sole constituents of dietary fiber. Being limited to the plant polymers only, this definition does not include undigestible polysaccharides from other sources such... 

Dietary fiber (DF) has taken on a larger meaning than its original definition of plant cell wall material resistant to the digestive process (IJ in animals or man. 

Definition Broken hulls of rice, Oryza sativa Uses Dietary fiber supplement in foods bulking agent, abrasive in cosmetics Manuf./Distrib. Doguet Rice Milling Trade Name Synonyms Aqua Pro II RB [Midwest Grain Prods. http //www.midwestgrain.com] Protex 20 t[Mid-Am. Food Sales4]... 

Dietary fiber The determination of dietary fiber has increased greatly in importance in recent years however, due partly to lack of a clear definition for dietary fiber, several standard methods exist. 

TABLE 5.1 Current Definitions of Prebiotics and Dietary Fibers... 

Several analytical methods are often available for the same parameter, and selection of the reference method can be critical, especially if the NIR technique is being developed for a specific purpose. For example, the U.S. Code of Federal Regulations (13) has specific definitions for nutrients appearing on the label, and it is important, if the NIR method is to be used for nutrition labeling or monitoring, that the reference method meet the definition of the component. The definition of a nutrient may also vary between countries, for example, as it does for dietary fiber, so regulations for the country of interest should also be considered. 

Over the last 20 years many studies have shown that dietary fiber may have a hypocholesterolemic effeet[111,112] However, the largely held public belief that all fibers are hypolipidemic is not supported by the experimental data. Bran, for instance, which is mainly constituted by cellulose and hemicellulose, does not seem to have any effect on serum lipids[113], whereas it has been shown that pectin, guar-gum and alfa-alfa saponins have a definite hypocholesterolemic effect[114,115,116] ... 

These findings might have practical implications thus, dietary fiber is known to decrease intestinal transit[122] and, as already discussed, some dietary fiber seems to have a hypocholesterolemic effect. Moreover, Wald et al. recently reported that gastrointestinal transit time was prolonged in the luteal phase of menstrual cycle when compared to the follicular phase[123] finally, many gastrointestinal hormones have a definite effect on small bowel motility [124]. 

H. Trowell, Definition of dietary fiber and hypotheses that it... 

In recent years, there has been increasing interest in those carbohydrates that escape absorption in the small intestine and enter the colon, where they may have specific health benefits due to their fermentation by the colonic microflora and their effect on gut physiology. This entry considers the definition, classification, dietary sources, methods of analysis, colonic fermentation, and health benefits of both resistant starch and oligosaccharides, and compares them with those of dietary fiber. 

There has been much debate of the definition of dietary fiber and in particular whether it should include carbohydrates other than nonstarch polysaccharides. Recently, the American Association of Cereal Chemists (AACC) proposed a new definition of dietary fiber, which would include both oligosaccharides and resistant starch as well as associated plant substances. This new definition would also require complete or partial fermentation and demonstration of physiological effects such as laxation, and reduction in blood glucose or blood cholesterol. A similar approach to include beneficial physiological effects is also proposed by the Food and Nutrition Board of the US Institute of Medicine. 

Thus, it is being increasingly recognized that oligosaccharides, resistant starch, and nonstarch polysaccharides are very similar especially in their effects on gut physiology and colonic fermentation. A comparison of their actions is summarized in Table 7. This inclusion of resistant starch and oligosaccharides in the definition of dietary fiber could have major implications for food labeling. 

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