Rice Fiber Research Articles

Stress-induced visceral analgesia assessed non-invasively in rats is enhanced by prebiotic diet.

To investigate the influence of repeated water avoidance stress (rWAS) on the visceromotor response (VMR) to colorectal distension (CRD) and the modulation of the response by a prebiotic diet in rats using a novel surgery-free method of solid-state manometry. Male Wistar rats fed a standard diet with or without 4% enzyme-treated rice fiber (ERF) for 5 wk were subjected to rWAS (1 h daily x 10 d) or no stress. The VMR to graded phasic CRD was assessed by intraluminal colonic pressure recording on days 0 (baseline), 1 and 10 (45 min) and 11 (24 h) after rWAS and expressed as percentage change from baseline. Cecal content of short chain fatty acids and distal colonic histology were assessed on day 11. WAS on day 1 reduced the VMR to CRD at 40 and 60 mmHg similarly by 28.9% ± 6.6% in both diet groups. On day 10, rWAS-induced reduction of VMR occurred only at 40 mmHg in the standard diet group (36.2% ± 17.8%) while in the ERF group VMR was lowered at 20, 40 and 60 mmHg by 64.9% ± 20.9%, 49.3% ± 11.6% and 38.9% ± 7.3% respectively. The visceral analgesia was still observed on day 11 in ERF- but not in standard diet-fed rats. By contrast the non-stressed groups (standard or ERF diet) exhibited no changes in VMR to CRD. In standard diet-fed rats, rWAS induced mild colonic histological changes that were absent in ERF-fed rats exposed to stress compared to non-stressed rats. The reduction of cecal content of isobutyrate and total butyrate, but not butyrate alone, was correlated with lower visceral pain response. Additionally, ERF diet increased rWAS-induced defecation by 26% and 75% during the first 0-15 min and last 15-60 min, respectively, compared to standard diet, and reduced rats' body weight gain by 1.3 fold independently of their stress status. These data provide the first evidence of psychological stress-related visceral analgesia in rats that was enhanced by chronic intake of ERF prebiotic.

현미 식이섬유를 첨가한 튀김가루의 품질 특성

In this study, frying mix was prepared containing 0.5, 1.0, 1.5 or 2.0% brown rice fiber(BRF). The samples along with a control were then compared regarding their quality characteristics, including pasting properties, spreadability, pick-up ratio, color, textural characteristics, moisture and oil contents, and sensory qualities, all to determine the optimal ratio of BRF. For the pasting properties of frying mix, the control group was evidenced by a significantly higher peak viscosity, through viscosity, and final viscosity than that observed in the BRF samples. Breakdown was the highest at the 1.0% addition level, and time to peak viscosity and pasting temperature were maximal with the 0.5% addition. There was no significant difference in setback among the experiments. Spreadability and pick-up ratio of frying batter were not significantly different among the samples. As the BRF content increased, the lightness, greenness decreased, whereas yellowness increased. The BRF samples presented significantly higher hardness of fried batter than the control group and there was no significant difference in crispiness among the samples. Moisture content of fried sweet potato decreased with increasing BRF and oil content was the maximum on the control group. In the sensory evaluation, appearance, color, flavor, savory taste, yellowishness, coating thickness, off-flavor, and oiliness were not significantly different among the fried sweet potato samples. Bindingness, crispiness, and chewiness were highest in the control samples but minimal at a addition level of 2.0%. The control group evidenced significantly higher overall acceptability than were observed in the BRF samples. In conclusion, the results demonstrated that 0.5~1.0% BRF may prove quite useful as a additive for frying mix in the preparation of fried sweet potato and may provide favorable textural and functional properties.

Quality Characteristics and Sensory Properties of Reduced-fat Emulsion Sausages with Brown Rice Fiber

We evaluated the effects of dietary fiber extracted from brown rice on the quality of reduced-fat emulsion sausage. Reduced-fat emulsion sausage was supplemented with brown rice fiber at levels of 0, 1, 2, 3, and 6%. Adding different levels of brown rice fiber affected the proximate composition of the reduced-fat emulsion sausages (p<0.05), except for protein content. Adding different levels of brown rice fiber influenced the physicochemical properties of the reduced-fat emulsion sausages. The cooking yield, emulsion stability, textural properties, and viscosity of the reduced-fat emulsion sausages containing brown rice fiber improved with increases in added brown rice fiber (p<0.05). The reduced-fat emulsion sausages containing 1-3% brown rice fiber generated sensory evaluation scores similar to those of the high-fat sausage control. These results indicate that reduced-fat emulsion sausages with 1-3% added brown rice fiber had the most acceptable sensory properties and highest quality characteristics compared to the others.

The effect of rice fibre fractions on the growth of co-cultures of probiotics.

The fermentation of rice dietary fibre was measured by the cell yield, pH, optical density specific growth rate and biomass using nine co-cultures of four probiotics at 0, 6, 24 and 48h incubation. The results from the fermentation of the soluble, insoluble and total dietary fibre (SDF, IDF, and TDF) of two rice varieties were compared. Overall there was no significant difference (p < 0.05) in the fermentation of the six different rice fibre fractions. However, co-cultures showed a preference for glucose as a fermentation substrate rather than the fibre fractions. Bifidobacteria species produced a higher cell count than the Lactobacillus species after 24 and 48h of fermentation (p < 0.05). There was evidence of synergistic activity with increased growth observed when lactobacilli and Bifidobacterium were grown together. Growth was limited by the pH reaching 4.2-4.45. Specific growth rates of the co-cultures varied for different culture combinations. Combinations of the same species produced less biomass than combinations of mixed species. Bifidobacterium breve + Bifidobacterium longum + Lactobacillus rhamnosus was the most efficient. These findings showed that synergism between microorganisms in co-cultures affected the degree of fermentation of dietary fibre.

New prebiotics from rice bran ameliorate inflammation in murine colitis models through the modulation of intestinal homeostasis and the mucosal immune system

Background. Enzyme-treated rice fiber (ERF) is a recently developed prebiotic product made from rice bran by heat-resistant amylase, protease and hemicellulase treatment. Although the detailed mechanism of inflammatory bowel disease (IBD) is still unclear, the role of the resident luminal bacteria and its interaction on the mucosal barrier seem to be an important factor in the development of IBD and its chronicity. With the objective of manipulating the intestinal microbiota in IBD, this study was carried out to evaluate the effects of ERF on IBD with using experimental colitis models. Methods. Three colitis models were used and they were induced by the oral administration of dextran sodium sulfate in male Sprague–Dawley rats or BALB/c mice and transferring CD4+ CD45RBhigh T cells to female SCID mice, sequentially their CD4+ T cells were retransferred to new SCID mice. The evaluation included the measurement of body weight, spleen weight, colon length, histological examination, serum and mucosal cytokine (tumor necrosis factor-alpha (TNF-α), an interferon-gamma (IFN-γ), interleukin-12 p70 (IL-12p70), IL-1β, IL-6, IL-4) analysis, mucosal serotonin (5HT), and organic acid production and a microbiota analysis of the cecal contents. The characteristics of T cell surface markers including CD4, CD69, CD45RB of spleen and mesenteric lymph nodes (MLN) were also analyzed. In addition, the effects of ERF on the change in the induction of dendritic cells (DCs) were evaluated. Results. The preventive effect of ERF on colitis was significantly superior to that of raw material rice bran or control group. An overexpression of inflammatory cytokine production was attenuated by ERF treatment, which was accompanied with a decrease in both the colonic mucosal damage and 5HT production. Furthermore, ERF significantly attenuated the T cell activation (CD4+CD69+) of spleen and MLN, and this characteristic was inherited by the retransferred mice. ERF significantly suppressed the growth of Clostiridium, and increased short-chain fatty acids (acetate, propionate and butyrate) content in colitis. The relatively hydrophilic fraction of ERF (ethanol–methanol soluble fraction) is therefore considered to have a potent ability to attenuate the induction of DCs. Conclusion. A new prebiotic, ERF, reduced inflammation by modulating the colonic environment and regulating immune cell differentiation. Although a more detailed study is required, this study showed the promising anti-inflammatory effects of an adjunctive prebiotic treatment for IBD.

Enhancement of short chain fatty acid formation by pure cultures of probiotics on rice fibre

SummaryThe formation of SCFA and the digestion of rice fibre using the following probiotics (Lactobacillus rhamnosus, Lactobacillus acidophilus, Bifidobacterium longum, Bifidobacterium breve) was compared using total dietary fibre (TDF), insoluble dietary fibre (IDF) and soluble dietary fibre (SDF) from two varieties (milling grades) of rice. The milling grade of the rice had no significant effect (P &lt; 0.05) on the SCFA formation and the digestion after 6, 24 and 48 h fermentation. SCFA formation from the fermentation of the fibre fractions of both rice varieties, followed the pattern of TDF &gt; SDF &gt; IDF for all the probiotics tested and major difference between the species was the time to form the SCFA. The pattern of SCFA formation from both rice fibre fractions was acetate &gt; propionate &gt; butyrate for all the organisms with no significant difference between the micro‐organisms (P &lt; 0.05) although the ratio of acetate:propionate:butyrate was lower for Bifidobacterium spp. Lactobacillus spp. digested 60–80% of fibre whereas Bifidobaceria digested 75–85% of the rice fibre fractions from both rice samples. There was no significant difference in the ability of the micro‐organisms tested to utilise the different varieties of rice (P &gt; 0.05).

Preventive effects of enzyme-treated rice fiber in a restraint stress-induced irritable bowel syndrome model

Irritable bowel syndrome (IBS) is a common health issue that is characterized by abdominal pain, abnormal bowel movements, altered visceral perception, and abnormal metabolism of 5-hydroxy triptamine (serotonin; 5HT). The use of prebiotics or probiotics treatment for IBS has become increasingly important as an adjunct to pharmaceutical options. The aim of this study was to determine the efficacy of enzyme-treated rice fiber (ERF) on an IBS model. We obtained a new prebiotic from defatted rice bran that was developed as an insoluble dietary fiber through amylase and hemicellulase treatment followed by removal of the soluble fraction. Containing approximately 70% hemicellulose, ERF is utilized by lactobacilli and subsequently converted to butyrate using Eubacterium limosum. We employed a restraint stress IBS model which involved the continuous application of stress for 4 h per day for 3 days. Polycarbophil Ca (PC) (500 mg/kg body weight) was used as a positive control and ERF was added to the diet at 4% in diet. During restraint stress, ERF significantly attenuated urgent fecal excretion, colonic mucosal 5HT secretion, and hyperalgesthesia compared with the control. ERF also significantly increased cecal butyrate production as well as total organic acid content. PC was only effective in regard to preventing increases in 5HT levels. Furthermore, there were no significant levels of pro-inflammatory markers CINC-1 and TNF-alpha among the groups. Although more detailed studies are needed, the ERF prebiotic demonstrated potency in attenuating major symptoms of IBS.

The influence of rice fibre fractions on the in vitro fermentation production of short chain fatty acids using human faecal micro flora

SummaryA study was conducted to assess the effects of rice dietary fibre on the fermentative activity of human faecal microflora. Dietary fibre was extracted from four commercially available Sri Lankan rice varieties [LD 356, AT 353 (red in colour); BG 352, and BG 358 (white in colour)], and separated into individual fractions of total dietary fibre (TDF), insoluble dietary fibre (IDF) and soluble dietary fibre (SDF). Four healthy human subjects were given a diet containing the four rice varieties for more than 4 months prior to the study. Faecal microflora was obtained from human volunteers, after the 4 months of rice based diet, and used for anaerobic fermentation of the individual rice fibres. Short Chain Fatty Acid (SCFA) production was analysed at 0, 2, 4, 6 and 24 h by gas liquid chromatography. Among the SCFA, acetate was the most abundant acid formed in all rice varieties. The fibre fractions from rice variety LD 356 (TDF16.73%, SDF 3.57%, 11.9% IDF) gave the highest yield of SCFA while the variety BG 358 gave the least. Total dietary fibre of all rice varieties contributed to produce more SCFA than the individual soluble dietary fibre and insoluble dietary fibre fractions.

Whole fat rice bran reduces the development of early aortic atherosclerosis in hypercholesterolemic hamsters compared with wheat bran

In this study, Golden Syrian hamsters were fed a nonpurified hypercholesterolemic diet containing 10% coconut oil, 0.05% cholesterol and 20% wheat bran for 2 weeks (HCD) and based on mean plasma cholesterol levels were divided into four groups of 15. Hamsters were then fed the HCD or the HCD containing either 20% de-fatted rice bran (rice fiber), 20% heat-stabilized whole fat rice bran (WFRB), or 20% oat bran in place of wheat bran for 10 weeks. The rice fiber, WFRB, and oat bran diets significantly lowered plasma total cholesterol and very low- and low-density lipoprotein cholesterol levels compared to the wheat bran diet with no reductions in high-density lipoprotein cholesterol. Also, the WFRB diet significantly lowered plasma nonHDL-C levels compared to the rice fiber and oat bran diets. Aortic fatty streak formation was significantly reduced by WFRB diet compared to the wheat bran and rice fiber diets but not the oat bran. This study shows that whole fat rice bran reduces plasma cholesterol levels and the development of early aortic atherosclerosis in hypercholesterolemic hamsters similar to oat bran.

RESTRUCTURED BEEF ROASTS CONTAINING RICE BRAN OIL AND FIBER INFLUENCES CHOLESTEROL OXIDATION AND NUTRITIONAL PROFILE1

ABSTRACT Rice fiber (RF) and rice bran oil (RBO) were added to restructured beef roasts as natural additives. Beef roasts containing either RF or RF/RBO had higher oxidative stability (P&lt;0.05) during storage at 4C than did beef roasts without additives (control). The TBARS values, the saturated fatty acid / unsaturated fatty acid ratio (SFA/UFA), and the 7‐ketocholesterol content of beef roasts with RF and RF/RBO were lower (P&lt;0.05) than those of controls during storage (0, 4, and 8 days). Vitamin E vitamers and UFA were higher than those of controls. Preliminary sensory data indicated beef roasts containing RF and RBO were acceptable to consumers.

Current concepts in optimum nutrition for cardiovascular disease.

For the past decade, nutritionists have focused on consensus guidelines (National Cholesterol Education Program) to reduce dietary saturated fatty acids, cholesterol, and excess body weight. However, researchers are looking at other ways that diet may influence the progression of cardiovascular disease, including lipoprotein oxidation, thrombosis progression, cardiac arrhythmia, and medication interaction. Some areas of investigation include the role of various fatty acids and supplements-in the form of vitamins, minerals, herbs, and functional foods-as well as traditional foods and diets from other parts of the world. This review outlines some of the new and relevant nutritional approaches including: specific fatty acids (omega 3, monounsaturated and trans fatty acids), dietary supplements (herbs, antioxidants, vitamins C and E, Coenzyme Q10, B vitamins and homocysteine, L-arginine, Chinese red yeast rice, garlic, soy, flax seed, and dietary fiber), food and drink (tea, nuts, plant-sterol and stanol-ester-containing spreads, alcohol, and grapefruit juice), and the Mediterranean diet. (c) 2000 by CHF, Inc.

ADSORPTION of BILE ACIDS ON CEREAL TYPE FOOD FIBERS

A study involving measurement and analysis of adsorption of common bile acids, namely cholic, deoxycholic, and lithocholic acids, on cereal type dietary fibers was conducted. the selected food fibers were oat fiber, rice fiber, barley fiber, corn bran, and wheat bran, which are all extensively used in processed foods. the adsorption data were measured at 37C and 25C, which correspond to approximate human body and room temperatures. Influence of particle size reduction, due to grinding, on a fiber's bile acid binding capacity was examined by using macro size (35–60 mesh) and micro size (100–300 mesh) fibers as adsorbents. the investigation also included the effects of medium pH and the chemical composition. the experimental data were correlated with the Langmuir and the Freundlich isotherms in order to utilize the data in future predictions and simulations.It was found that the particle size reduction, accompanied by surface area increase, has a significant influence on the adsorption capacity of the fiber. Macro size fibers adsorbed the same bile acid with the following trend: oat &gt; barley &gt; rice &gt; wheat &gt; corn; while micro size fibers followed a somewhat different trend: rice &gt; barley &gt; oat &gt; wheat &gt; corn. This was due to the surface area change after grinding, and a positive correlation between the surface area and the adsorption capacity was observed in each case. the adsorption was favored by acid pH surroundings, and it was positively correlated with the hydrophobicity of the bile acid. were adsorbed on the same fiber with the following trend: lithocholic acid &gt; deoxycholic acid &gt; cholic acid. Fibers adsorbed more bile acid at 25C than they did at 37C. However, the increase in the uptake capacities were not very signipcant.

Adsorption of water on cereal-bread type dietary fibers

A study involving the water sorption characteristics of cereal-bread type food fibers was conducted, using a gravimetrical adsorption apparatus. Water adsorption data for four dietary fibers, corn bran, wheat bran, oat fiber and rice fiber, were measured at 278, 288, 298 and 310 K. The results showed that the adsorption of water vapor on these fibers are primarily due to physical forces, and all fibers investigated exhibited energetically heterogeneous surfaces. It was found that the distribution of the major components of the dietary fiber has an impact on the fiber's water sorption capacity. The isotherm data were correlated by using the BET and GAB multilayer adsorption models. The BET equation gave accurate correlations for up to 35 to 40% of the saturation pressure, while the GAB equation provided much better correlation of the data for the higher relative pressures.

DIFFUSION of WATER IN CEREAL‐BREAD TYPE FOOD FIBERS

ABSTRACTA study involving water vapor diffusion in cereal‐bread type dietary fibers was conducted. the experimental diffusivity data were derived from adsorption rate measurements for water vapor in wheat bran, oat fiber, corn bran, and rice fiber at 278, 288, 298 and 310 K, using a gravimetric method. the effective bulk diffusivities were determined by employing a Fickian model for isothermal diffusion, and were subsequently correlated by an Arrhenius type expression. Thermal effects on the rate measurements were evaluated through a nonisothermal analysis. the rate at which water diffused in different fibers followed the trend: rice &gt; oat &gt; corn &gt; wheat. the effective diffusion coefficients of water in all fibers were in the range of 10‐3‐10−4 cm2/s. As expected, all fiber samples were saturated faster at higher temperatures.

Effect of Rice Fiber on Human Fecal Microflora

The effects of brown rice, containing fourfold as much dietary fiber as polished rice, on the human fecal microflora were determined. Significantly increased numbers of Bifidobacterium adolescentis and Enterococcus faecalis were observed during the brown rice intake, whereas the total counts and the numbers of bacteroides, Eubacterium aerofaciens, and Escherichia coli during the intake were lower than those before and after the intake. Lower numbers of clostridia and low incidences of Clostridium paraputrificum and C. perfringens were observed during the brown rice intake.

Effects of rice fiber on fecal weight, apparent digestibility of energy, nitrogen and fat, and degradation of neutral detergent fiber in young men.

The effects of rice fiber on fecal weight, transit time, frequency of defecations, digestibility of nutrients and blood status were investigated in 5 healthy young men. Each of them consumed a brown rice diet and then a polished rice diet for 2 weeks respectively. Both diets contained 1.2 g protein per kg body weight. The brown rice diet contained 2 times as much dietary fiber as the polished rice diet. When they consumed the brown rice diet, it showed an increase of fecal weight and decrease of digestibility of energy, nitrogen and fat. Nitrogen balance was not significantly different and kept zero balance on both diets. Concentration of plasma cholesterol was not significantly different. The results suggest that rice fiber produced an increase in fecal weight, which is assumed to be effective in preventing colonic disease in advanced countries and does not affect plasma lipid level.

Effect of brown rice and soybean dietary fiber on the control of glucose and lipid metabolism in diabetic rats

We have studied the effect of brown rice and soybean dietary fiber on the oral glucose tolerance test, plasma-insulin, -glucagon, -triglycerides, and cholesterol levels in control and streptozotocin-induced diabetic rats. Plasma glucose level after glucose loading in diabetic rats fed soybean fiber was considerably lower (60 and 120 min) than the corresponding group not receiving the fiber. Soybean fiber given to control rats decreased the plasma glucose at 60 min after the oral glucose test. Rice fiber decreased the plasma glucose of diabetic rats only at 60 min and the control rats fed with or without fiber elicited a comparable glycemic response. While soybean fiber significantly lowered the glucagon and triglyceride levels in both control and diabetic rats, rice fiber had no effect on these blood parameters. In conclusion, this study demonstrated the potential benefit of soybean dietary fiber over rice fiber in diabetes treatment with additional advantages resulting from its ease in usage either in a mixture of water or milk products and cooking. As well, being devoid of a disagreeable taste so characteristic of other fibers, patient acceptance is more forthcoming.