Rice Fiber Research Articles

Characteristics of Rice Analogue from Composite Flour and Seaweed Puree

The research aimed to determine the interaction of corn flour formulation, yellow sweet potato, arrowroot starch, and concentration of Gracilaria sp. seaweed slurry on the physicochemical properties of rice analogue. This research was conducted using a factorial randomized group design. This research consists of two factors. The first factor is the composite flour formulation (corn flour: yellow sweet potato flour: arrowroot starch) with different ratios; the second is Gracilaria sp. seaweed slurry concentration, which consists of four levels, namely 0 %, 1 %, 2 %, 3 % (w w-1). This research shows an interaction between the composite flour formulation and the concentration of Gracilaria sp. seaweed porridge on analogue rice’s water, fat, fibre, and antioxidant content. Analogue rice is known to have a water content ranging from 6.10 % to 8.25 %, ash content ranging from 1.45 % to 4.09 %, fat content ranging from 2.40 % to 5.91 %, and protein content ranging from 1.31 % to 3.60 %; carbohydrate levels range from 80.96 % to 87.99 %. Besides that, the analogue rice fibre content ranged between 1.33 % to 4.48 %, and the antioxidant activity was 83.32 % to 86.46 %.

The influence of rice fiber and nanoclay on mechanical properties and mechanisms of clayey soil stabilization

Conventional stabilizers such as cement and lime are extensively used to improve the mechanical properties of soils. However, these materials suffer from geo-environmental concerns, especially greenhouse gas emissions. In this respect, incorporating sustainable and renewable materials into the soil is an effective technique to enhance its mechanical properties. This study investigated the effect of rice fibers (as a low-cost and eco-friendly material) and nanoclay on soil’s mechanism and mechanical performance. In this study, pure soil samples and three nanoclay dosages (0.4, 0.8, and 1%) and three rice fiber ratios (0.3, 0.6, and 0.9%) in three lengths of 5, 10, and 15 mm in random distribution were tested. The prepared samples were characterized through compaction, unconfined compressive strength (UCS), direct shear strength, tensile strength, California bearing ratio (CBR), and scanning electron microscopy (SEM) examinations. First, the optimum amount of nanoclay was determined based on the compressive strength test. Then, the effect of optimum nanoclay and randomly distributed rice fibers was investigated on the mechanical properties of stabilized soil. The results showed that the shear and compressive strengths of the reinforced soil were higher than those of the control samples. An increase in the dosage of rice fibers improved the failure strain, soil ductility, and shear strength. The optimum amount of fibers was 0.9%, exceeding which led to fiber twisting and agglomeration. However, increasing the nanoclay content decreased the failure strain. According to the microscopic examination, when fibers were combined with nanoclay, the interaction between soil particles and fibers increased due to the filling property and the formation of a viscous gel. Overall, fiber added with nanoclay improved the mechanical properties of clay soil and could be used as a low-cost and sustainable option for soil improvement.

Optimization of Manufacturing Parameters and Experimental Study of Rice Straw Fiber-Based Plant Fiber Seedling Pots

In order to improve and alleviate environmental pollution caused by the disposal of seedling pots, a rice straw fiber-based headed vegetable seedling pot material, which is suitable for mechanical transplantation and biodegradable, was studied. Used rice straw as the main raw material, a five-factor and five-level (1/2 full implementation) quadratic regression orthogonal rotation central of rotation combination test method. The experimental factors included the beating degree of rice straw fiber, quantity, the proportion of rice fiber, neutral sizing agents, and wet strength agent mass fraction. The performance evaluation index included dry and wet tensile strength, burst strength, tear strength, air permeance, and degradation period. The results showed that when the parameter combination of the beating degree of rice straw fiber was 50 ± 1°SR, the quantity was 87.5 ± 4 g/m2, the proportion of fiber in rice was 70%, the neutral sizing agents mass fraction was 1 ± 0.25%, and the wet strength agent mass fraction was 1.5 ± 0.1%. The dry tensile strength was ≥ 1.8 kN·m−1, the wet tensile strength was ≥ 0.7 kN·m−1, the burst strength was ≥ 140 kPa, the tear strength was ≥ 350 m·N, the air permeance was ≤ 1.33 μm/Pa·s, and the degradation period was ≤ 80 d. The dry tensile strength reduction rate was 0.0274 kN/(m·d) and the wet tensile strength reduction rate was 0.0113 kN/(m·d), during the nursery period [30, 40], while the dry tensile strength was ≥ 1 kN·m−1 and the wet tensile strength was ≥ 0.4 kN·m−1 during the transplanting period.

Biomass waste from rice and wheat straw for developing composites by stereolithography additive manufacturing

In this work, and for the first time according to literature, various sizes of wheat and rice fiber obtained from agricultural residues were incorporated into a photocurable resin for the fabrication of a composite by stereolithography additive manufacturing. Thermal stability studies by thermogravimetric and differential scanning calorimetry showed significant differences depending on the fiber size used. Additionally, an in-depth characterization of both biomass and printed composites by scanning electron microscopy demonstrates how the fiber size is of great importance in the production of this type of composite. Mechanical properties such as elastic modulus, tensile strength and percentage elongation at break showed a correspondence between the value of these properties and the fiber size used. Thermally, structures with relatively low conductivity values are obtained, which provides these novel composites with a great potential to be suitable as boards in buildings.

Effect of mechanical properties of rice stem and its fiber on the strength of straw rope

As a low-cost and light-weight flexible rope, the production and use of straw rope can promote the transformation of straw into industrial raw materials and improve the utilization rate of straw. However, non-standard production makes the straw rope prone to failure and breakage. In this paper, the Chinese Zhendao 10# variety was selected, and mechanical tests were carried out on the components of rice fiber and rice stem. The tensile strength of the stem is 29.02 MPa, the elastic modulus is 1.03 GPa, and the shear strength is 8.52 MPa. The strength of rice fiber satisfies the Weibull distribution and has been verified by experiments; and the statistical strength of stem fiber is used for the strength analysis of straw rope. Secondly, this paper establishes the strength model of the rice straw rope and explores the failure mechanism through tensile test and explicit dynamic simulation. The results showed that shear failure of rice stem and tensile failure of stem fiber are the main mechanisms for the failure of straw rope. The stress distribution of the straw rope is consistent with the mathematical model. The research could provide a new idea and method for the strength prediction and evaluation of straw rope.

Effectiveness of Rice Straw Fiber as Land Cover for Soil Erosion Control

For the first time, this experimental research analyzed the efficacy of rice straw fiber as soil cover in controlling slope erosion using a physical model. Three variations of rainfall intensity, soil slope degree, and rice straw fiber were conducted in this research. The results showed that rice straw fiber in the physical model had reduced the amount of erosion significantly. In general, a higher erosion rate was obtained with the increases of rainfall intensity and soil slope degree. The experiment was conducted with the percentage 30%, 60%, and 90% of soil cover using rice fiber straw, reducing erosion rates by 92.09%, 95.55%, and 98.21 %, respectively. Therefore, the higher the percentage of rice straw fiber used as soil cover, the smaller the ground will be affected by erosion. The ratio from the soil affected by erosion was 7.91%, 4.45%, and 1.79%, respectively. The result reveals that there is a significant decrease in erosion due to the increase of fiber used in the experiments. Meanwhile, the amount of erosion in the physical model without soil cover was 98.21% for the same rainfall severity and soil slope degree. This research showed that the application of rice straw fiber as a soil surface shield is highly effective in controlling slope erosion.

Scanning agro-industrial wastes as substrates for fungal biopesticide production: Use of Beauveria bassiana and Trichoderma harzianum in solid-state fermentation

As a waste valorisation option, agro-industrial residues (rice husk, apple pomace, whisky draff, soy fiber, rice fiber, wheat straw, beer draff, orange peel and potato peel) were tested as feasible substrates for fungal conidia production. Solid-state fermentation tests were conducted at laboratory scale (100 g) with Beauveria bassiana or Trichoderma harzianum which conidia are reported to have biopesticide properties. Conidia concentrations with all substrates were at least two orders of magnitude above inoculum except for both fibers, thus demonstrating the possibilities of the proposed waste recovery option. Highest productions were at least 1 × 109 conidia g−1 dry matter for Beauveria bassiana using rice husk or potato peel and higher than 5 × 109 conidia g−1 dry matter for Trichoderma harzianum using beer draff, potato peel or orange pomace. Principal component analysis has been used to understand which parameters affect the most fungal conidia production for an easier evaluation of other similar wastes, being air-filled porosity and initial pH for Beauveria bassiana and cumulative oxygen consumption, initial moisture and total sugar content for Trichoderma harzianum.

Kajian Pembuatan Beras Analog Berbasis Tepung Komposit dengan Penambahan Konsentrasi Bubur Rumput Laut (Gracilaria sp.) dan Gliserol Monostearat

Rice consumption is estimated to increase along with the increase in population every year. Analog rice is one alternative to functional food diversification and was expected to help reduce people's dependence on rice consumption. The addition of seaweed and glycerol monostearate in the study was intended to improve the shape of rice grains from previous studies which were sticky so that the shape of the rice was lost, enriching antioxidants and fiber from analog rice. The purpose of this study was to determine the interaction and effect of the addition of seaweed pulp extracts and glycerol monostearate to analog rice. The design of this study is a factorial randomized block design (RBD-F). Factor I is seaweed with 3 levels of concentration {1%, 2%, 3%}, factor II is glycerol monostearate with 4 levels of concentration {1%, 2%, 3%, 4%}. The results of the study the highest value on the water content of the addition of seaweed 3% by 7.51%; carbohydrate glycerol monostearate level of 1% was 91.78%; the antioxidant activity of rice and rice in seaweed concentration of 3% by 27.35% and 25.57%; The highest value of rice fiber and rice in the treatment of Seaweed 3% and GMS 3% by 1.53% and 1.63%. Organoleptic results in the form of appearance (5.33 = interesting), taste (4.44 = somewhat like), fondness (4.33 = somewhat like), aroma (2.67 = not fishy), and texture (2.33 = not sticky).

Estudio experimental sobre el corte con láser de CO2 a baja potencia del compuesto de plástico reforzado con fibras naturales

La aplicación de los plásticos reforzados con fibras naturales en la industria puede aumentar mediante el uso de tecnologías más rápidas y flexibles, como el corte por láser. La naturaleza anisotrópica y el grado de combustión de las fibras naturales en este tipo de compuestos hacen que el procesamiento con láser sea muy desafiante. Este estudio trata sobre el rendimiento de corte de un láser de CO2 a baja potencia, para cortar placas de compuestos poliméricos (matriz de resina poliéster y epoxi), reforzado con fibras naturales (abacá y cascarilla de arroz), de 3 mm de espesor promedio. Se empleó un diseño experimental DOE y un análisis de varianza Anova para determinar los parámetros significativos e influyentes en la calidad de corte y el efecto térmico en el material. Los parámetros de procesamiento fueron la potencia de corte, velocidad de corte y tipo de matriz termoestable. Los cortes con una zona mínima afectada por el calor, de aproximadamente 600 mm y un Ra mínimo de 3.18 μm, se lograron al trabajar con 76 W y 14 mm/s de potencia y velocidad de corte, respectivamente, en el material compuesto de matriz poliéster reforzado con fibra de arroz.

Biocomposites from Rice Straw Nanofibers: Morphology, Thermal and Mechanical Properties

Agricultural residues are major potential resources for biomass and for material production. In this work, rice straw residues were used to isolate cellulose nanofibers of different degree of oxidation. Firstly, bleached rice fibers were produced from the rice straw residues following chemical extraction and bleaching processes. Oxidation of rice fibers mediated by radical 2,2,6,6-tetramethylpiperidine 1-oxyl (TEMPO) at pH 10 was then applied to extract rice cellulose nanofibers, with diameters of 3–11 nm from morphological analysis. The strengthening capacity of rice nanofibers was tested by casting nanocomposite films with poly(vinyl alcohol) polymer. The same formulations with eucalyptus nanofibers were produced as comparison. Their thermal and mechanical performance was evaluated using thermogravimetry, differential scanning calorimetry, dynamic mechanical analysis and tensile testing. The glass transition of nanocomposites was shifted to higher temperatures with respect to the pure polymer by the addition of rice cellulose nanofibers. Rice nanofibers also acted as a nucleating agent for the polymer matrix. More flexible eucalyptus nanofibers did not show these two phenomena on the matrix. Instead, both types of nanofibers gave similar stiffening (as Young’s modulus) to the matrix reinforced up to 5 wt.%. The ultimate tensile strength of nanocomposite films revealed significant enhancing capacity for rice nanofibers, although this effect was somehow higher for eucalyptus nanofibers.

Production and recovery of cellulases through solid-state fermentation of selected lignocellulosic wastes

Orange peel, apple pomace and rice fibre from vegetal beverage manufacturing were assessed for the production of cellulases though solid state fermentation (SSF). No increment in cellulases activity was observed during SSF, being the maximum activity that of the raw waste 8 ± 1, 7.8 ± 0.1 and 2.1 ± 0.2 International units (IU) g−1 Dry Matter for apple pomace, orange peel and rice fibre, respectively. In view of the results, the influence of the main cellulases extraction parameters in the activity recovery from raw waste was assessed. Results show a maximum activity recovery of 105 ± 27% for apple pomace in an extraction ratio 1:2 (w:v) using distilled water as extracting agent. 97 ± 13% and 139 ± 11% activity recovery for orange peel and rice fibre, respectively, were achieved at 1:3 (w:v) extraction ratio and distilled water with no agitation. Finally, zero waste strategies (aerobic stabilization and anaerobic digestion) were successfully applied to valorise the remaining waste after extraction.

Anti-inflammatory effects of rice bran components.

Neuroinflammation has been implicated in the pathology of various psychiatric and neurodegenerative disorders. Accumulating evidence suggests that food components can modulate inflammatory processes, and therefore it could be hypothesized that such nutrients might exhibit therapeutic efficacy against these brain diseases. Rice bran is often discarded as a waste product, although it contains a wide range of potentially useful substances. Several rice fiber components from rice bran have been described as having antiinflammatory properties. This review summarizes the evidence supporting a modulatory effect of rice fiber components on symptoms in several animal models for neuroinflammation. In vitro studies on immune cells and in vivo studies on nutritional intervention in animal models of central and peripheral inflammation are discussed in the context of the potential use of rice fiber components for prevention and treatment of brain diseases in which neuroinflammation is involved.

Isolation, characterization and functionalities of bio-fiber gums isolated from grain processing by-products, agricultural residues and energy crops

Potentially valuable water soluble bio-fiber gums (hemicellulose B) were prepared from low-valued grain processing by-products, agricultural residues and energy crops by an alkaline extraction followed by ethanol precipitation. The bio-fiber gum (BFGs) from all these sources are very rich in soluble dietary fiber (87.2–93.6%) except from wheat bran and sugarcane bagasse (only 60.3 and 55.5% respectively) and they are predicted to be non-caloric in human diets qualifying as non-caloric food ingredient in many products. The sugar composition of these BFGs showed that they were typical arabinoxylans containing high molar ratio of arabinose to xylose with some other sugars such as galactose, glucose, galacturonic acid and glucuronic acid in the side chains. The yield of pure BFG from these plant materials varied from 2.33 (rice fiber) to 25.13% (corn bran) and they all, except BFG from wheat bran, are very good emulsifiers for stabilizing oil in water emulsions. Their ORAC values ranged from about 7000 to 29,000 μmole Trolox/100 g sample showing that they have the ability to provide antioxidant activity in foods, as well as offering the other functionalities and health-promoting benefits of dietary fiber. The ORAC values of BFGs are higher than their respective original plant materials indicating that the antioxidant-rich portions of the various plant materials can be solubilized and fractionated by the present alkaline extraction process.

Preliminary Study on The Potential of Hybrid Rice Husk with Kapok Fiber and Hybrid Rice Husk with Coconut Fiber as Landfill Liner Material

Abundance of agricultural waste in Malaysia namely rice husk (RH), kapok fiber (KF) and coconut fiber (CF) has been increasing over the years. This cause disposal problem and air pollution problem from burning activity. In line with the Malaysian Government Policy on the application of green technology concept through the 5R's practice, this agricultural waste has a potential to be commercialized as material for landfill liner. A factor that governs the workability of landfill liner materials is the permeability should be less than 1x10 -9 m/s. Therefore, a low permeability material needs to be installed to minimise the environmental impact on the leachate intrusion into groundwater. A series of standard tests to find environmental and geotechnical properties such as atterberg limit test (liquid limit, plastic limit, compaction test), permeability test (falling head method), leachate characteristics and heavy metal test were conducted at various ratio of hybrid materials (KC:RH and KC: CF in the ratio of 1:1 and 1:2 respectively). Experimental results confirmed that the hydraulic conductivity of the mixture of KC:RH:KF in the ratio of 1:1:1 is 7.29 x 10- 11 m/s was less than 10 -9 m/s, satisfying the requirement for landfill liner materials. Heavy metal testing showed that this hybrid material (RH:KF and RH:CF for ratio 1:2) were able to reduce at least 50 % of the leachate contaminants. The proposed hybrid materials (RH:KF and RH:CF) is a green material for the landfill (as it can improve heavy metal adsorption), increase the workability of the landfill by improving the conductivity of the conventional liners), minimizing manpower on site (no need expertise for installation) and reduction in cost (in terms of the use of waste materials).

헤미셀룰라아제 첨가가 현미 식이섬유 식빵의 품질에 미치는 영향

헤미셀룰라아제를 0.005, 0.010, 0.015, 0.020%로 첨가하여 제조한 현미 식이섬유 식빵 반죽의 pH 및 발효 팽창력, 현미 식이섬유 식빵의 품질 특성인 pH, 비용적, 굽기 손실률, 수분 함량, 색도, 조직감 및 관능검사의 결과는 다음과 같았다. 1차 발효 전 반죽의 pH는 대조군과 헤미셀룰라아제 첨가군 간에 유의적인 차이가 없었으며, 1차 발효 후 반죽의 pH는 헤미셀룰라아제 첨가군들이 대조군보다 유의적으로 높았고, 식빵의 pH는 대조군보다 헤미셀룰라아제 첨가군들이 유의적으로 낮았다. 발효 시간에 따른 반죽의 발효 팽창력은 대조군과 헤미셀룰라아제 첨가군들 모두 발효 시간이 길어질수록 유의적으로 증가하였다. 식빵의 비용적과 굽기 손실률은 헤미셀룰라아제 첨가군들이 대조군보다 유의적으로 높았다. 식빵의 수분 함량은 헤미셀룰라아제 0.020% 첨가군이 40.19%로 가장 낮았고, 대조군과 헤미셀룰라아제 0.005%, 0.010%, 0.015% 첨가군 간에는 유의적인 차이가 없었으며, 수분활성도는 헤미셀룰라아제 첨가군들이 대조군보다 유의적으로 높았다. 식빵의 명도는 대조군보다 헤미셀룰라아제 첨가군들이 다소 낮았다. 녹색도는 헤미셀룰라아제 0.015% 첨가군이 -0.62로 가장 낮았고, 대조군과 헤미셀룰라아제 0.005% 첨가군과 대조군은 각각 -0.81, -0.80으로 유의적으로 높았으며, 두 시료 간에는 유의적인 차이가 없었다. 황색도는 헤미셀룰라아제 0.005% 첨가군이 13.65로 가장 높았고, 헤미셀룰라아제 0.020% 첨가군이 12.86으로 가장 낮았다. 식빵의 견고성, 점착성과 씹힘성은 대조군 보다 헤미셀룰라아제 첨가군들이 유의적으로 낮았다. 응집성과 탄력성은 대조군과 헤미셀룰라아제 첨가군 간에 유의적인 차이가 없었다. 복원성은 헤미셀룰라아제 0.020% 첨가군이 0.49로 가장 낮았고, 대조군과 헤미셀룰라아제 0.005% 첨가군은 각각 0.51, 0.51로 유의적으로 높았으며, 두 시료 간에는 유의적인 차이가 없었다. 식빵의 소비자 기호도 검사 결과 색상과 향미는 대조군과 헤미셀룰라아제 첨가군 간에 유의적인 차이가 없었다. 부드러움은 헤미셀룰라아제 0.020% 첨가군이 6.78로 가장 높았고, 헤미셀룰라아제 0.010% 첨가군이 5.45로 가장 낮았다. 종합적인 기호도는 헤미셀룰라아제 0.020% 첨가군이 6.30으로 가장 높았고, 헤미셀룰라아제 0.010% 첨가군이 5.60으로 가장 낮았다. 식빵의 특성 강도 검사 결과 쌀겨향, 쓴맛, 떫은맛 및 거친 정도는 대조군과 헤미셀룰라아제 첨가군 간에 유의적인 차이가 없었다. 이상의 결과를 종합해 보면 헤미셀룰라아제 0.020% 첨가는 반죽의 발효 팽창력, 식빵의 비용적, 조직감 및 소비자 기호도 등의 품질 특성을 고려할 때 현미 식이섬유 식빵의 품질 특성에 좋은 영향을 미칠 수 있을 것으로 생각하였다.

Search for novel circulating cancer chemopreventive biomarkers of dietary rice bran intervention in Apc(Min) mice model of colorectal carcinogenesis, using proteomic and metabolic profiling strategies.

There is strong epidemiological evidence indicating that consumption by humans of whole-grain foods including rice bran may be associated with a low incidence of cancer, especially in the colorectum. Molecular processes associated with cancer development may be retarded by fiber consumption. Consequently, intervention with dietary fiber might be suitable as a cancer chemoprevention strategy in high-risk populations. Here, we searched for putative molecular mechanism-based efficacy biomarkers of rice fiber consumption in the plasma of mice characterized by a genetic propensity to develop gastrointestinal adenomas. The hypothesis was tested that metabolic and proteomic changes in blood reflect the chemopreventive activity of rice bran. Apc(Min) mice received diet supplemented with rice bran at 5, 15, and 30%. Blood and tissue samples were taken. Plasma was subjected to MS-based proteomic and metabolic profiling analyses as well as assessment of hematocrit values. Gastrointestinal tracts were removed and adenomas were counted and their size was measured so that total tumor burden could be calculated. The hypothesis was tested that metabolic and proteomic changes in blood reflect chemopreventive activity. Rice bran consumption reduced adenoma burden and number in a dose-related fashion when compared to controls. Metabolic profiling data demonstrated strong clustering of the groups indicating that metabolic pathways are perturbed. Proteomic analysis identified adiponectin as a molecule that was significantly altered, which may play a role in tumor suppression.

Emulsion Mapping in Pork Meat Emulsion Systems with Various Lipid Types and Brown Rice Fiber.

This study was conducted to evaluate emulsion mapping between emulsion stability and cooking yields, apparent viscosity, and hardness of reduced-fat pork emulsion systems. The reduced-fat emulsion systems were supplemented with different lipid types and brown rice bran fiber (BRF) concentrations. Compared to the control with 30% back fat, lower emulsion stability and higher cooking yield of meat emulsion systems were observed in T1 (30% back fat+1% BRF), T2 (30% back fat+2% BRF), T3 (30% back fat+3% BRF), T4 (30% back fat+6% BRF), and T15 (10% back fat+10% canola oil+2% BRF). Lower emulsion stability and higher apparent viscosity were observed in T1, T2, T3, T4, and T8 (20% back fat+3% BRF) compared to the control. Lower emulsion stability and higher hardness was detected in all treatments compared with the control, except T5 (20% back fat), T10 (10% back fat+10% canola oil+2% BRF), T11 (10% back fat+10% olive oil+2% BRF), T12 (10% back fat+10% grape seed oil+2% BRF), and T13 (10% back fat+10% soybean oil+2% BRF). This approach has been found particularly useful for highlighting differences among the emulsified properties in emulsion meat products. Thus, the results obtained with emulsion mapping are useful in making emulsified meat products of desired quality characteristics, partially replacing pork back fat with a mix of 10% back fat, 10% canola oil and 2% BRF was most similar to the control with 30% pork back fat.

The Hypolipidemic and Hypoglycemic Activities of Fermented Brown Rice Fibers by Regulating PPARα and ChREBP in the Livers of C57BL/6J Mice

The fermentation of brown rice produces black vinegar that has been suggested with beneficial metabolic effects; however, the mechanisms of actions of fermented brown rice have not been studied. We found that fermented brown rice extracts, especially a fraction of fermented brown rice fibers (FBRF), exhibited hypolipidemic and hypoglycemic activities in vivo. The oral administration of FBRF to C57BL/6J mice reduced plasma cholesterol, triglycerides, lowdensity- lipoprotein cholesterol levels, hepatic lipid accumulation and adipocyte size. The activation and induction of hepatic PPARα and subsequent regulation of its target gene expressions in fatty acid uptake and oxidation were the major mechanism for reducing plasma and hepatic triglyceride concentrations. In addition, FBRF improved glucose tolerance and insulin sensitivity. FBRF feeding reduced the expressions of hepatic ChREBP, a key transcription factor in gluconeogenesis, and pro-inflammatory cytokines, thus improved insulin resistance. These results demonstrated that FBR, especially FBRF, shows potent hypolipidemic and anti-diabetic activities through regulating the expression of genes associated with lipid, glucose metabolism and inflammatory cytokines.

Anti-Colitis Effects of Brown Rice Reported by Experimental Studies

Brown (unpolished) rice is a good source of vitamins, minerals, and dietary fiber and is consumed as a health food, particularly in Asian countries. Although a limited number of studies have investigated the anti-colitis effects of brown rice, including rice bran and treated brown rice, some have reported the protective effects of brown rice in animal models of dextran sulfate sodium-induced colitis in the following settings: 1) Rice bran oil, 2) Brown rice fermented by Aspergillus oryzae, 3) Enzyme-treated rice fiber, and 4) Kurozu (fermented vinegar made from brown rice). The possible mechanisms underlying the anti-colitis effects of brown rice include anti-oxidant effects, inhibition of proinflammatory cytokine production, myeloperoxidase activity, neutrophil infiltration in the colonic mucosa, activation of nuclear factor kappa B (NF-κB), and improvement of dysbiosis. However, the active components in dietary products derived from brown rice or treated brown rice have not yet been identified. This report summarizes the studies demonstrating the anti-colitis effects of brown rice or treated brown rice in animal models of colitis.

The influence of environmental factors on the adhesion of combinations of probiotics to rice fibre fractions

Nine co-cultures of the Bifidobacterium and Lactobacillus species were tested for their ability to adhere to insoluble dietary fibre (IDF1, IDF2), soluble dietary fibre (SDF1, SDF2), and total dietary fibre (TDF1, TDF2) from two rice varieties (RR1 and RR2). Combinations of the same genus (BB + BL and LA + LR) showed 30-40 % (poor) adhesion, and combinations of different genera showed 40-50 % (moderate) adhesion, which is significantly higher (p < 0.05) than the combinations of same genus. The increase in adhesion with species from different genera suggests some synergistic activity. The microbial combinations had the ability to adhere to dietary fibre fractions as early as 30 min. Colonization of rice fibre by bacterial cells was affected by the temperature, with adhesion being higher at 37 °C than at room temperature. The optimal pH value for adhesion was 4.2-4.5. This study observed that the combinations tested had a moderate percentage of adhesion in the presence of bile, low pH (4.3-4.5) and pancreatin, irrespective of the type of co-culture. In addition, adhesion was not affected by an increase in NaCl and Tween 80. Adhesion was affected by disaccharides and polysaccharides. The amount of adhesion of co-cultures was not significantly affected by the substrate (p > 0.05). Results indicated that rice fibre fractions are suitable hosts for the probiotics tested.