Recent progress in dietary fiber (plantix) in human nutrition

Properties and physiological effects of dietary fiber-enriched meat products: a review

Meat is a rich source of high biological proteins, vitamins, and minerals, but it is devoid of dietary fiber, an essential non-digestible carbohydrate component such as cellulose, hemicellulose, pectin, lignin, polysaccharides, and oligosaccharides. Dietary fibers are basically obtained from various cereals, legumes, fruits, vegetables, and their by-products and have numerous nutritional, functional, and health-benefiting properties. So, these fibers can be added to meat products to enhance their physicochemical properties, chemical composition, textural properties, and organoleptic qualities, as well as biological activities in controlling various lifestyle ailments such as obesity, certain cancers, type-II diabetes, cardiovascular diseases, and bowel disorders. These dietary fibers can also be used in meat products as an efficient extender/binder/filler to reduce the cost of production by increasing the cooking yield as well as by reducing the lean meat content and also as a fat replacer to minimize unhealthy fat content in the developed meat products. So, growing interest has been observed among meat processors, researchers, and scientists in exploring various new sources of dietary fibers for developing dietary fiber-enriched meat products in recent years. In the present review, various novel sources of dietary fibers, their physiological effects, their use in meat products, and their impact on various physicochemical, functional, and sensory attributes have been focused.

Effect of dietary fiber on properties and acceptance of meat products: a review

Meat is an important source of all essential nutritional components of our daily diet as it content most of the essential amino acids, fatty acids, vitamins, and minerals which are lack in plant based food, but it is devoid of dietary fiber, which is very essential component for normal physiological/biochemical process. During meat products processing, its functional values can be improved by supplementation of dietary fiber rich vegetative substances like cereal and pulse flour, vegetable and fruits pulp, etc. by this process, a significant proportion of required daily allowance of dietary fiber can be fulfilled for the frequent meat consumers. The consumption of meat products fortified with of dietary fiber can lead to the prevention of diseases like coronary heart disease, diabetes, irritable bowel disease, obesity, etc. On the other hand, the dietary fiber can effectively be incorporated in the processed meat products as binders, extender, and filler, they can significantly replace the unhealthy fat components from the products; increase acceptability by improving nutritional components, pH, water-holding capacity, emulsion stability, shear press value, sensory characters, etc. of finished products. Addition of dietary fiber in the meat products can increase the cooking yield therefore the economic gain as well.

Novel trends in development of dietary fiber rich meat products-a critical review

Meat and meat products are generally recognized as good sources of high biological value proteins, fat-soluble vitamins, minerals, trace elements and bioactive compounds. Changes in socioeconomic factors in recent years have increased the consumer's preference for ready to eat foods including meat products. The processing of meat and meat products leads to generation of many functional compounds beneficial to human health but most of those foods are rich in fat, added salts but deficient in complex carbohydrates like dietary fiber and pose a health hazard that somehow is proved to be a predisposing factor for cardiovascular diseases, colon cancer, obesity including diabetes mellitus. With increasing consciousness among consumers about their nutrition and well being, there is a growing concern over nutritional diseases of affluence. Therefore an increase in dietary fiber inclusion in daily diet has been recommended. For adults, the recommended acceptable intakes of dietary fiber are 28-36 g/day, 70-80 % of which must be insoluble fiber. The insoluble fraction of dietary fiber has been related to intestinal regulation whereas soluble fiber is associated with decrease in cholesterol level and absorption of intestinal glucose. So incorporation of dietary fibers from different sources in meat products would help to enhance their desirability. Dietary fiber sources are generally agricultural byproducts that are comparatively cheap and incorporation in meat products reduces its overall cost. Whole grains and cereal brans are the rich source of insoluble fiber and pectins, gums, starch and other storage polysaccharides have high content of the soluble fraction. With this background, the effect of various dietary fibers on the quality attributes of meat and meat products with its physiological role has been reviewed here.

The effect of high-fibre diet on plasma lipoproteins and hormones in genetically obese Zucker rats

The effects of prolonged substitution of readily digested carbohydrates (wheat starch) for poorly digested carbohydrates (mixture of various fibres and crude potato starch) on plasma lipids, lipoproteins and hormones were investigated in Zucker, genetically obese rats. Lean rats were also studied in parallel. Usually, plasma lipid and insulin levels and insulin/glucose ratio were higher in obese rats vs. their lean littermates. High-fibre diet intake led to weight loss in both obese and lean rats. With a high-fibre diet, plasma lipid, insulin and glucose postprandial levels in both groups were reduced when compared with their respective control animals. Dietary fibre modified the lipoprotein profile. Triglycerides and cholesterol were reduced in all studied lipoprotein fractions. The study of high density lipoprotein (HDL) fraction in rats fed a high-fibre diet demonstrated a decrease in the HDL1 subpopulation and in the apolipoprotein (apo)E proportion. The findings show that a high-fibre diet modulates plasma lipid, insulin and glucose levels and modifies the plasma lipoprotein distribution and composition in normolipaemic, lean rats as well as in hyperlipaemic, genetically obese rats.

Gravimetric method for the determination of insoluble and soluble dietary fibres

The present paper describes a simple method for the determination of the insoluble and soluble dietary fibres in food. In a first step, starch and proteins are removed by enzyme treatment. The insoluble dietary fibres are determined gravimetrically after centrifugation and washing of the residue with water, ethanol, acetone and diethyl ether. The water-soluble dietary fibres are recovered from the supernatant liquid of the centrifugation by dialysis, freeze-drying, and subsequent weighing. The method has been used for the determination of dietary fibres in by-products from the industry.

Physiological effects of fibre-rich types of bread. 1. The effect of dietary fibre from bread on the mineral balance of young men

1. Twelve young adult male volunteers were given a low-fibre white bread diet (9 g neutral-detergent fibre (NDF)/d) and a medium-fibre coarse-bran bread diet (22 g NDF/d), each lasting 20 d. In ad third period of 20 d the volunteers were subdivided in groups of four, consuming a high-fibre coarse-bran bread diet (35 g NDF/d), a medium-fibre fine-bran bread diet (22 g NDF/d, bran particle size less than 0.35 mm) or a wholemeal bread diet (22 g NDF/d). Retention of calcium, magnesium, iron, zinc and copper were determined during each 20 d period. 2. An increase of the amount of dietary fibre (through bran) from 9 g to 22 g NDF/d resulted in a significantly increased mineral intake, but also faecal excretion increased significantly; mineral retention remained almost constant. 3. Both intake and faecal excretion of all minerals studied, except faecal Ca, increased further (P less than 0.05) on the diet providing 35 g NDF/d; only Fe balance decreased significantly. No significant differences with respect to intake, excretion (except urinary Ca) and balance of the minerals could be detected between the coarse-bran bread and fine-bran bread diets providing 22 g NDF/d. Faecal Fe, Cu balance and Mg balance increased significantly during the wholemeal bread period compared to the coarse-bran bread diet providing 22 g NDF. 4. Serum cholesterol increased significantly, i.e. by 0.3 mmol/l, during the coarse-bran bread diet providing 22 g NDF, compared to the white-bread diet. 5. It is concluded that increasing the amount of bran in bread does not appear to affect mineral balance considerably but there seems to be an influence on mineral availability. The increased intake was accompanied by increased faecal excretion.

Effect of long generation times on growth of Bacteroides thetaiotaomicron in carbohydrate-induced continuous culture

We investigated the ability of Bacteroides thetaiotaomicron, an obligate anaerobe from human colonic microflora, to grow in a carbohydrate-limited continuous culture at generation times ranging from 3.5 to 28 h per division. Four carbohydrates were tested: glucose, N-acetylglucosamine, glucuronic acid, and glucosamine. At a generation time of 3.5 h per division, the growth yields for bacteria growing on glucose, N-acetylglucosamine, and glucuronic acid were 76, 68, and 50 g of cells (dry weight) per mol of substrate, respectively. Growth yields at 28 h per division were 61, 52, and 37 g/mol of substrate, respectively. When glucosamine was the carbohydrate source, a stable population of bacteria was attainable only at generation times longer than 12 h per division. Growth yields at 15 and 32 h per division were 11 and 33 g/mol of substrate, respectively. There was no significant variation with increasing generation times in the specific activities of selected glycolytic enzymes, of disaccharidases such as alpha- and beta-glucosidases and alpha- and beta-galactosidases, or of the polysaccharidase chondroitin sulfate lyase. By contrast, the pattern of fermentation products varied with both the generation time and the carbon source. At a generation time of 3.5 h per division, the main products from the fermentation of glucose were acetate and succinate, with a trace of propionate. At 28 h per division, propionate concentrations were higher and succinate concentrations were lower than at 3.5 h per division. The products from the fermentation of glucosamine were the same as those from glucose fermentation. However, when N-acetylglucosamine was fermented, the concentration of acetate was much higher at all generation times than when glucose was the carbon source. When glucuronic acid was the carbon source, acetate was the main fermentation product, and only traces of propionate and succinate were detected. Another characteristic that varied with the growth rate was the ability of B. thetaiotaomicron to produce the inducible enzyme alpha-glucosidase when exposed to maltose. The ability of the organism to produce this enzyme declined with increasing generation times.

Comparison of dye and pellet gastrointestinal transit time during controlled diets differing in protein and fiber levels

The purpose of this experiment was to compare repeated measurements of the gastrointestinal transit times of simultaneously ingested dye and radiopaque pellets. Pellet transit was calculated as the time required for 80% of the dose to excreted and as mean transit time (MTT-S). comparisons were made in seven healthy women during three controlled diet periods, two containing different levels of protein and the third added fiber (16 g refined cellulose). Each experimental period was about on month. Dietary protein level or phases of the menstrual cycle had no significant effect on gastrointestinal transit time. Cellulose consumption also did not significantly affect transit time, but it did reduce the variability between repeated 80% transit determinations in four subjects, between MTT-S in three subjects, and between dye in two subjects. The two different measures of pellet transit, 80% pellets and MTT-S, and the dye were significantly correlated, although the correlations were generally stronger during the cellulose diet period. These results suggest that the menstrual cycle, refined cellulose, and dietary protein level have limited effects on gastrointestinal transit time and that measurement of transit as passage of 80% pellets and MTT-S are comparable.

[Effect of gum guar in the diet on the utilization of 14C-labeled protein and protein hydrolysates in young rats]

Beginning on the 25th day of life and for 2 weeks therafter Sprague-Dawley rats were fed a casein diet containing 10% of gum guar. The animals were given. 14C algal protein or 14C algal protein hydrolysate by stomach tube and the radioactivity in some tissues and tissue proteins was determined 3 h after the application. Radioactivity in blood and in respiratory CO2 was measured up to 3 h and 6 h, respectively, after the application. The results indicate no effect of gum guar on the utilization of the protein or of the amino acids of the protein hydrolysate.