Fiber components

Fiber components are the principal energy source for colonic bacteria with a further contribution from digestive tract mucosal polysaccharides. Rate of fermentation varies with the chemical nature of the fiber components. Short-chain fatty acids generated by bacterial action are partiaUy absorbed through the colon waU and provide a supplementary energy source to the host. Therefore, dietary fiber is partiaUy caloric. The short-chain fatty acids also promote reabsorption of sodium and water from the colon and stimulate colonic blood flow and pancreatic secretions. Butyrate has added health benefits. Butyric acid is the preferred energy source for the colonocytes and has been shown to promote normal colonic epitheUal ceU differentiation. Butyric acid may inhibit colonic polyps and tumors. The relationships of intestinal microflora to health and disease have been reviewed (10). 

Water-Holding Capacity (WHC). AU polysaccharides are hydrophilic and hydrogen bond to variable amounts of water. HydratabUity is a function of the three-dimensional stmcture of the polymer (11) and is kifluenced by other components ki the solvent. Fibrous polymers and porous fiber preparations also absorb water by entrapment. The more highly crystalline fiber components are more difficult to hydrate and have less tendency to sweU. Stmctural features and other factors, including grinding, that decrease crystallinity or alter stmcture, may iacrease hydratioa capacity and solubUity. 

Molecular Interactions. Various polysaccharides readily associate with other substances, including bile acids and cholesterol, proteins, small organic molecules, inorganic salts, and ions. Anionic polysaccharides form salts and chelate complexes with cations some neutral polysaccharides form complexes with inorganic salts and some interactions are stmcture specific. Starch amylose and the linear branches of amylopectin form inclusion complexes with several classes of polar molecules, including fatty acids, glycerides, alcohols, esters, ketones, and iodine/iodide. The absorbed molecule occupies the cavity of the amylose helix, which has the capacity to expand somewhat to accommodate larger molecules. The starch—Hpid complex is important in food systems. Whether similar inclusion complexes can form with any of the dietary fiber components is not known. 

NORMAND F L, ORY R L, MOD R R (1987) Binding of bile acids and trace minerals by soluble hemicelluloses of rice The ability of rice fiber components to bind bile acids may play a role in lowering serum cholesterol. Food Technology, 41(2) 86-90. 

Possible future studies include chemical characterization of the fiber components of the dephytinized bran and the water insoluble fraction and in vitro binding studies using whole bran and the fractions (18). 

Concentrates are made by extracting water-soluble sugars and other compounds from defatted meals or flours. This is typically a secondary extraction, using acidic ethanol-water in a chain-type or basket-type continuous extractor for processing flakes, or acidic water extraction of flour in vats, followed by spray-drying (8). Acidic polar solvents are used at or near the isoelectric point of the protein to minimize its solubility and loss. The reextracted flakes may then be ground into a flour. Concentrates are more bland than defatted flours, but still contain the fiber components of the kernel. After extraction with acidic ethanol or water, concentrates... 

Modern C3 materials for automotive applications, such as components of the car body, are synthesized according to the flow scheme of Fig. 9.2. Here an integrated synthesis of both filler and binder components is taken as a cost-effective approach. In high-tech applications it is more customary to independently optimize the preparation of the fiber component [15,19, 20, 36, 37] and then the C3 synthesis in separate processes with extensive quality control measures in-between. 

Little agreement has been reached as to which dietary components or which food processes physiologially affect mineral availability. Many plant foods contain phytic acid, oxalic acid or other dietary fiber components that can be shown to chelate minerals. The effect of these dietary substances upon the final bioavailability of the mineral in question will depend upon the digestibility of the chelate (106). 

With respect to fiber components that are dyed with completely different dye classes, the ability to use single-bath techniques (exhaust and continuous) depends on the interaction between the dyes and the compatibility of their dyeing procedures. 

Bobb. L.C. and PJV1. Shankar "Tapered Optical Fiber Components and Sensors, Microwave J. 219 (May 1992). 

R.G. Fulcher and S.S. Miller, Structure of Oat Bran and Distribution of Dietary Fiber Components. In P.J. Wood, (Ed.), Oat Bran, American Association of Cereal Chemists, St. Paul, MN (1993), ppl-24. 

Reinboth, B., Hanssen, E., Cleary, E. G., and Gibson, M. A. (2002). Molecular interactions of biglycan and decorin with elastic fiber components Biglycan forms a ternary complex with tropoelastin and microfibril-associated glycoprotein 1./. Biol. 

K. M. Barford, R. A. McDonald, G. G. "Molecular Interactions of Dietary Fiber Components" presented at 179th ACS National Meeting, Houston, TX, 1980. 

With a few exceptions, sulfur dyes [1] are employed to dye cellulosic fibers. The main applications are the dyeing of corduroy, velveteen, denim articles, twill work clothes, tarpaulins, and backpack fabrics. The dyeing of the cellulosic fiber component of blended fabrics (polyester/cotton blends above all) is increasingly important. 

The joint use of anionically modified and normal PES types can be exploited for differential dye effects (joint application of different classes of dyes that differ in their affinity to the fiber components). 

These treatments may be divided into three main classifications -- treatment of the fiber with soluble salts, treatment of the fiber by processes wherein various water-insoluble chemical complexes are precipitated around the fiber or dispersed throughout the fiber mass, and treatment of the fiber by chemical reaction between the cel-ulose and/or other fiber components by suitable reactants. The last two classifications are the most permanent of the treatments. 

Biosensors and devices may also include fiber components. Biosensors essentially contain two main components. These are the sensing element, which senses the molecule of interest, and the transducer, which generates a signal. Amyloid fibrils and other protein nanofibers could be used in biosensors in two ways. The first is as a scaffold to immobilize the sensing element on a nanoscale as described above. The second use is as a coating on the transducer where the presence of the protein fiber could enhance device performance. This enhancement could be carried out either with or without the aid of a further conductive coating (see Section 4.1 above). 

Jeltema, M. A., Zabic, M. E., and Thiel, L. J. (1983). Prediction of cookie quality from dietary fiber components. Cereal Chem. 60 227-230. 

Skeletal muscle is composed of muscle cells, thin and thick filaments, and endomysium, a connective tissue containing fibroblasts that holds the fibers together. Mechanical loading regulates normal muscle metabolism in the absence of normal tensile loading muscle atrophy results. Interactions between thick (myosin) and thin (actin) filaments result in lines or bands containing one or more of the muscle fiber components. The H band represents overlap of only the thick filaments whereas the I band represents the area of overlap of thin and thick filaments. The z lines are the points at which the sarcomere repeats itself. 

Cellulose. Fiber components differ in their ability to bind to bile (41), the primary route of excretion of manganese (9). Cellulose, the most abundant natural fiber, has been studied for its potential effects on bile and lipid metabolism (42). It is naturally present in high fiber diets and is also commonly added to many commercially-produced food products. Previous studies have shown cellulose to decrease intestinal uptake of a variety of minerals, including zinc, phosphorus, calcium, magnesium, and iron (32,43,44). In many cases, however, the effect of cellulose has not been considered to be anti-nutritional (32). It has been generally believed that cellulose has a lower binding affinity for minerals than other constituents of dietary fiber (33,45). 

Fiber components can bind zinc and other minerals, possibly rendering the minerals unavailable for absorption by the animal body (1, 2,. The effect of fiber on zinc balance of human subjects was reviewed previously (4) and appears to be related to level and kind of fiber, level of zinc, other components of the diet, and length of study period. One of the dietary components which may affect zinc availability is oxalic acid. 

X-ray diffraction measurements may be made on the fibrous material. Although the method is limited in application, it does enable definite statements to be made about the minimal length of the crystalline fiber component. Thus the minimal length of the anhydro-n-glucose polymer chain in ramie was found to be about 1000 A, and in wood, about 600 A. From these data it may be calculated that the degree of polymerization is greater than 200,and indeed may be found to be the approximate length of the basic molecular unit. ... 

Theander, O. (1987). Chemistry of dietary fiber components. Scand. J. GasSroenSeroi., Suppl. 22(129), 21-28,... 

A study on diet and colon cancer was reported by W. Willett s group (Willett et at., 1990) (Table 11.3). The study examined various components of the diet, such as fiber, fat, and meat. The fiber component was divid into cereal fiber and fruit fiber. The fat component was divided into meat fat, dairy fat, saturated fat, and unsaturated fat. The meat component was divided into beef, pork, and lamb, and into rare versus well-done Styles of cooking. The body mass index, as defined in the Obesity chapter, was also recorded. The study was part of the Nurses Health Study Cohort, which was inibated in 1976 and involved 121,700 female nurses. Every 2 years, the nurses filled in a questionnaire that asked about various risk factors for disease. The questionnaire asked, for example, about 61 foods and their frequency In the diet. The foods were chosen to allow epidemiologists to make broad statements regarding the component nutrients. 

Measurements were obtained from selected yarn pseudomorphs, and the figures indicate a fair amount of consistency for the single-fiber yarn type and the paired-fiber yarn shape. Not as easily measured were yarn pseudomorphs with multiple components, either in the form of a single strand with numerous fiber components or a plied yarn pseudo-morph. Because encmstations had formed along the surfaces of the formations, it was difficult to identify clear boundaries for them. 

Free Radical Characteristics and Reactions in Weathered Wood. Wood, wood fiber components, and isolated lignin contain certain amounts of free radicals that are detectable by ESR spectroscopy (SS, S9). Unexposed green wood with 69% moisture content (in dark and in vacuo) was found (77a) to contain no free radicals. A trace amount of free radicals may be produced in the presence of oxygen, and most of these free radicals are generated in wood during mechanical preparation (90) as well as in wood exposed to electromagnetic irradiation. ESR studies revealed that wood interacts readily... 

Shah, N., Atallah, M.T., Mahoney, R.R. and Pellett, P. 1982. Effect of dietary fiber components on fecal nitrogen excretion and protein utilization in growing rats, J. Nutr., 112 658-666. 

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