Effects of the extraction conditions on the yield and composition of rice bran oil extracted with ethanol-A response surface approach

Rice bran oil was obtained from rice bran by solvent extraction using ethanol. The influence of process variables, solvent hydration (0-24% of water, on mass basis), temperature (60-90 degrees C), solvent-to-rice bran mass ratio (2.5:1 to 4.5:1) and stirrer speed (100-250 rpm) were analysed using the response surface methodology. The extraction yield was highly affected by the solvent water content, and it varied from 8.56 to 20.05 g of oil/100 g of fresh rice bran (or 42.7-99.9% of the total oil available) depending on the experimental conditions. It was observed that oryzanol and tocols behave in different ways during the extraction process. A larger amount of tocols is extracted from the solid matrix in relation to gamma-oryzanol. It was possible to obtain values from 123 to 271 mg of tocols/kg of fresh rice bran and 1527 to 4164 mg of oryzanol/kg of fresh rice bran, indicating that it is feasible to obtain enriched oil when this renewable solvent is used. No differences in the chemical composition of the extracted oils were observed when compared to the data cited in the literature. (C) 2011 The Institution of Chemical Engineers. Published by Elsevier B.V. All rights reserved.

Liquid-liquid equilibria for systems composed of rice bran oil and alcohol-rich solvents: Application to extraction and deacidification of oil

The liquid-liquid equilibria of systems composed of rice bran oil, free fatty acids, ethanol and water were investigated at temperatures ranging from 10 to 60 degrees C. The results of the present study indicated that the mutual solubility of the compounds decreased with an increase in the water content of the solvent and a decrease in the temperature of the solution. The experimental data set was correlated by applying the UNIQUAC model. The average variance between the experimental and calculated compositions was 0.35%, indicating that the model can accurately predict behavior of the compounds at different temperatures and degrees of hydration. The adjustment of interaction parameters enables both the simulation of liquid-liquid extractors for deacidification of vegetable oil and the prediction of phase compositions for the oil and alcohol-rich phases that are generated during cooling of the stream exiting the extractor (when using ethanol as the solvent). (C) 2012 Elsevier Ltd. All rights reserved.

Formation and stability of oil-in-water nanoemulsions containing rice bran oil: in vitro and in vivo assessments

Abstract Background Nanoemulsions have practical application in a multitude of commercial areas, such as the chemical, pharmaceutical and cosmetic industries. Cosmetic industries use rice bran oil in sunscreen formulations, anti ageing products and in treatments for skin diseases. The aim of this study was to create rice bran oil nanoemulsions using low energy emulsification methods and to evaluate their physical stability, irritation potential and moisturising activity on volunteers with normal and diseased skin types. Results The nanoemulsion developed by this phase diagram method was composed of 10% rice bran oil, 10% surfactants sorbitan oleate/PEG-30 castor oil, 0.05% antioxidant and 0.50% preservatives formulated in distilled water. The nanoemulsion was stable over the time course of this study. In vitro assays showed that this formulation has a low irritation potential, and when applied to human skin during in vivo studies, the nanoemulsion improved the skin's moisture and maintained normal skin pH values. Conclusion The results of irritation potential studies and in vivo assessments indicate that this nanoemulsion has potential to be a useful tool to treat skin diseases, such as atopic dermatitis and psoriasis.

Influence of the use of rice bran extract as a source of nutrients on xylitol production

Xylose-to-xylitol bioconversion using 2.5 or 10% (v/v) rice bran extract was performed to verify the influence of this source of nutrients on Candida guilliermondii metabolism. Semisynthetic medium (SM) and sugarcane bagasse hemicellulosic hydrolysate detoxified with ion-exchange resins (HIE) or with alteration in pH combined with adsorption onto activated charcoal (HAC) were fermented in 125 mL Erlenmeyer flasks at 30 ºC and 200 rpm for 72 hours. Activated charcoal supplemented with 2.5% (v/v) rice bran extract was fermented by C. guilliermondii in a MULTIGEN stirred tank reactor using pH 5.0 and 22.9/hour oxygen transfer volumetric coefficient. Higher values of xylitol productivity (0.70, 0.71, and 0.62 g.Lh-1) and xylose-to-xylitol conversion yield (0.71, 0.69, and 0.63 g.g-1) were obtained with 2.5% (v/v) rice bran in semisynthetic medium, ion-exchange resins, and activated charcoal, respectively. Moreover, during batch fermentation, the xylitol volumetric productivity and fermentation efficiency values obtained were 0.53 g.Lh-1 and 61.1%, respectively.

Nutritional composition of rice bran submitted to different stabilization procedures

In order to inactivate enzymatic deterioration, whole rice bran samples were subjected to two stabilization methods. Changes in nutritional value in terms of, concerning chemical composition, minerals and fatty acid content, were evaluated to supplement existing data and promote the utilization of rice bran in the human diet. The following homemade heat treatments were applied: roasting on a conventional stove or heating in a microwave oven. Based on the results, the different heating methods affected sample composition, since the levels of some nutrients of treated samples showed significant changes (p<0.05) compared to corresponding raw samples. The rice bran treated on a conventional stove produced products with lower moisture (5.14±0.10 g/100 g) and nutrients such as sodium 11.8%; palmitic acid 9.9% and stearic acid 8.1%. The microwave oven procedure resulted in better nutrient preservation, with slightly higher moisture content (6.28±0.10 g/100 g), and appears to be a practical and rapid tool for home heat stabilization of rice bran.

THERMOSTABILITY OF XYLANOLYTIC ENZYMES PRODUCED BY LENTINULA EDODES UFV70

Xylanolytic enzymes produced by Lentinula edodes UFV70, cultivated in eucalyptus sawdust/rice bran medium, were stable at 50, 60 and 65 degrees C for 21 hours, losing only 15-25% activity. Fungus incubation at 50 degrees C for 12 hours and at 65 degrees C for 24 hours increased the amount of xylose produced.

Chemical Interesterification of Blends of Palm Stearin, Coconut Oil, and Canola Oil: Physicochemical Properties

trans-Free interesterified fat was produced for possible usage as a margarine. Palm stearin, coconut oil, and canola oil were used as substrates for chemical interesterification. The main aim of the present study was to evaluate the physicochemical properties of blends of palm stearin, coconut oil, and canola oil submitted to chemical interesterification using sodium methoxide as the catalyst. The original and interesterified blends were examined for fatty acid composition, softening and melting points, solid fat content, and consistency. Chemical interesterification reduced softening and melting points, consistency, and solid fat content. The interesterified fats showed desirable physicochemical properties for possible use as a margarine. Therefore, our result suggested that the interesterified fat without trans-fatty acids could be used as an alternative to partially hydrogenated fat.

Thermostability of xylanolytic enzymes produced by Lentinula edodes UFV70

Xylanolytic enzymes produced by Lentinula edodes UFV70, cultivated in eucalyptus sawdust/rice bran medium, were stable at 50, 60 and 65ºC for 21 hours, losing only 15-25% activity. Fungus incubation at 50ºC for 12 hours and at 65ºC for 24 hours increased the amount of xylose produced.

Rice oil as a soybean oil replacement in weanling pig diets

The motivation for including oils in the diets of weanling pigs is to increase dietary energy density to meet the pigs' energy requirements. The purpose of this study was to determine the digestible and metabolizable energy values of semi-refined rice oil (RO) and refined soybean oil (SO) for weanling pigs (Experiment 1), as well as to evaluate how replacing SO with RO in weanling pig diets affects performance, intestinal histology, organ morphometry and the occurrence of diarrhea (Experiment 2). In Experiment 1,21 barrows, averaging 19.63 +/- 0.37 kg body weight (BW), were used in a randomized complete block design experiment, with seven replications per treatment and one pig per experimental unit (metabolism cage). The treatments consisted of a reference diet and two test diets. The test diets were obtained by using 90% of the reference diet and 10% of RO or SO. The experimental period consisted of a 7 days adaptation period, followed by a 5 days collection period of feces and urine. The values of the apparent digestible energy, apparent metabolizable energy and N-corrected apparent metabolizable energy of the oils were, respectively, 26.24, 25.78 and 26.01 MJ kg(-1) for RO and 31.74, 31.35 and 31.51 MJ kg(-1) for SO. In Experiment 2, 120 weaned pigs, castrated males and females, averaging 6.74 +/- 0.42 kg BW, were used in a randomized complete block design experiment, with eight replications per treatment and three pigs per experimental unit (pen) to evaluate the effects of five replacement levels of SO with RO in isonutritive weanling pig diets. The treatments were as follows: 4:0 basal diet with 4% of SO; 3:1 basal diet with 3% of SO and 1% of RO; 2:2 basal diet with 2% of SO and 2% of RO; 1:3 basal diet with 1% of SO and 3% of RO; and 0:4 basal diet with 4% of RO. No effects of the replacement levels were observed in the weanling pigs' performance, organ morphometry or in their occurrence of diarrhea. However, a quadratic effect on the villus width and a cubic effect on the villus height:crypt depth ratio were observed in the duodenum. Therefore, if the determined values of energy are used in the feed formulation, refined soybean oil can be replaced with semi-refined rice oil in weanling pig diets without affecting their growth performance. (C) 2011 Elsevier B.V. All rights reserved.

Genetic variation of germination cold tolerance in Japanese rice germplasm

Low temperatures at the initial stages of rice development prevent fast germination and seedling establishment and may cause significant productivity losses. In order to develop rice cultivars exhibiting cold tolerance, it is necessary to investigate genetic resources, providing basic knowledge to allow the introduction of genes involved in low temperature germination ability from accessions into elite cultivars. Japanese rice accessions were evaluated at the germination under two conditions: 13 degrees C for 28 days (cold stress) and 28 degrees C for seven days (optimal temperature). The traits studied were coleoptile and radicle length under optimal temperature, coleoptile and radicle length under cold and percentage of the reduction in coleptile and radicle length due to low temperature. Among the accessions studied, genetic variation for traits related to germination under low temperatures was observed and accessions exhibiting adequate performance for all investigated traits were identified. The use of multivariate analysis allowed the identification of the genotypes displaying cold tolerance by smaller reductions in coleoptile and radicle lenght in the presence of cold and high vigour, by higher coleoptile and radicle growth under cold.

Diversity of propanil-degrading bacteria isolated from rice rhizosphere and their potential for plant growth promotion

The herbicide propanil has long been used in rice production in southern Brazil. Bacteria isolated from contaminated soils in Massaranduba, Santa Catarina, Brazil, were found to be able to grow in the presence of propanil, using this compound as a carbon source. Thirty strains were identified as Pseudomonas (86.7%), Serratia (10.0%), and Acinetobacter (3.3%), based on phylogenetic analysis of 16S rDNA. Little genetic diversity was found within species, more than 95% homology, suggesting that there is selective pressure to metabolize propanil in the microbial community. Two strains of Pseudomonas (AF7 and AF1) were selected in bioreactor containing chemotactic growth medium, with the highest degradation activity of propanil exhibited by strain AF7, followed by AF1 (60 and 40%, respectively). These strains when encapsulated in alginate exhibited a high survival rate and were able to colonize the rice root surfaces. Inoculation with Pseudomonas strains AF7 and AF1 significantly improved the plant height of rice. Most of the Pseudomonas strains produced indoleacetic acid, soluble mineral phosphate, and fixed nitrogen. These bacterial strains could potentially be used for the bioremediation of propanil-contaminated soils and the promotion of plant growth.

Functional characterization of sugarcane mustang domesticated transposases and comparative diversity in sugarcane, rice, maize and sorghum

Transposable elements (TEs) account for a large portion of plant genomes, particularly in grasses, in which they correspond to 50%-80% of the genomic content. TEs have recently been shown to be a source of new genes and new regulatory networks. The most striking contribution of TEs is referred as "molecular domestication", by which the element coding sequence loses its movement capacity and acquires cellular function. Recently, domesticated transposases known as mustang and derived from the Mutator element have been described in sugarcane. In order to improve our understanding of the function of these proteins, we identified mustang genes from Sorghum bicolor and Zea mays and performed a phenetic analysis to assess the diversity and evolutionary history of this gene family. This analysis identified orthologous groups and showed that mustang genes are highly conserved in grass genomes. We also explored the transcriptional activity of sugarcane mustang genes in heterologous and homologous systems. These genes were found to be ubiquitously transcribed, with shoot apical meristem having the highest expression levels, and were downregulated by phytohormones. Together, these findings suggest the possible involvement of mustang proteins in the maintenance of hormonal homeostasis.

Rice husk derived waste materials as partial cement replacement in lightweight concrete

In this study rice husk ash (RHA) and broiler bed ash from rice husk (BBA), two agricultural waste materials, have been assessed for use as partial cement replacement materials for application in lightweight concrete. Physical and chemical characteristics of RHA and BBA were first analyzed. Three similar types of lightweight concrete were produced, a control type in which the binder was just CEMI cement (CTL) and two other types with 10% cement replacement with, respectively, RHA and BBA. All types of similar lightweight concrete were prepared to present the same workability by adjusting the amount of superplasticizer. Properties of concrete investigated were compressive and flexural strength at different ages, absorption by capillarity, resistivity and resistance to chloride ion penetration (CTH method) and accelerated carbonation. Test results obtained for 10% cement replacement level in lightweight concrete indicate that although the addition of BBA conducted to lower performance in terms of the degradation indicative tests, RHA led to the enhancement of mechanical properties, especially early strength and also fast ageing related results, further contributing to sustainable construction with energy saver lightweight concrete.

Selenate and selenite on yield and agronomic biofortification with selenium in rice

The objective of this work was to evaluate the effect of doses of selenate and selenite on rice (Oryza sativa) biofortification with Se, as well the influence of these forms of Se in the levels of P, S, Fe, and Zn in grains. The experiment was conducted in a greenhouse, in pots with 4 dm(3) of a sandy clay loam Latosol, with medium texture, in a 5x2 factorial arrangement with five doses of Se (0, 0.75, 1.50, 3.0, and 6.0 mg dm(-3)) and two forms of Se (selenate and selenite). Selenate provided greater efficiency of root uptake of Se, plant-use efficiency, translocation from roots to shoots, and content of this element in rice grains. The application of Se during fertilization influences the levels of P, S, and Zn, but does not affect those of Fe in rice grains.

Production of a xylose-stimulated beta-glucosidase and a cellulase-free thermostable xylanase by the thermophilic fungus Humicola brevis var. thermoidea under solid state fermentation

Humicola brevis var. thermoidea cultivated under solid state fermentation in wheat bran and water (1:2 w/v) was a good producer of beta-glucosidase and xylanase. After optimization using response surface methodology the level of xylanase reached 5,791.2 +/- A 411.2 U g(-1), while beta-glucosidase production was increased about 2.6-fold, reaching 20.7 +/- A 1.5 U g(-1). Cellulase levels were negligible. Biochemical characterization of H. brevis beta-glucosidase and xylanase activities showed that they were stable in a wide pH range. Optimum pH for beta-glucosidase and xylanase activities were 5.0 and 5.5, respectively, but the xylanase showed 80 % of maximal activity when assayed at pH 8.0. Both enzymes presented high thermal stability. The beta-glucosidase maintained about 95 % of its activity after 26 h in water at 55 A degrees C, with half-lives of 15.7 h at 60 A degrees C and 5.1 h at 65 A degrees C. The presence of xylose during heat treatment at 65 A degrees C protected beta-glucosidase against thermal inactivation. Xylanase maintained about 80 % of its activity after 200 h in water at 60 A degrees C. Xylose stimulated beta-glucosidase activity up to 1.7-fold, at 200 mmol L-1. The notable features of both xylanase and beta-glucosidase suggest that H. brevis crude culture extract may be useful to compose efficient enzymatic cocktails for lignocellulosic materials treatment or paper pulp biobleaching.