Bran Acid Research Articles

Valorization of Industrial Byproduct-Rice Bran Acid Oil: Direct Extraction and Evaluation of Ferulic Acid and Phytosterols/Triterpene Alcohols for Cosmetic Applications

Valorization of Industrial Byproduct-Rice Bran Acid Oil: Direct Extraction and Evaluation of Ferulic Acid and Phytosterols/Triterpene Alcohols for Cosmetic Applications

Subcritical liquified dimethyl ether and supercritical fluid carbon dioxide extraction of gamma oryzanol from rice bran acid oil

Gamma oryzanol (γ-oryzanol) is a bioactive compound in rice bran acid oil, a by-product of the rice bran oil refining process that possesses various pharmacological properties. This study investigated the effect of green technology supercritical fluid carbon dioxide extraction (SF–CO2) and subcritical liquified dimethyl ether extraction (SUBLDME) of γ-oryzanol from rice bran acid oil. Results showed that subcritical liquified dimethyl ether extracted oryzanol at 4865.25 mg/100 g from rice bran acid oil without pretreatment by hexane and ethyl acetate compared with supercritical fluid carbon dioxide extraction (2569.04 mg/100 g), with high extraction efficiency (62.73 vs 18.86%). Further extraction of the filter cake remaining from supercritical fluid carbon dioxide extraction from rice bran acid oil without pretreatment using subcritical liquified dimethyl ether extraction gave the highest percentage yield and γ-oryzanol contents (8128.51 mg/100 g). Supercritical fluid carbon dioxide extraction together with subcritical liquified dimethyl ether extraction showed promise as a green technology to extract γ-oryzanol from rice bran acid oil. Further studies are required to optimize both SF-CO2 and SUBLDME extraction methods to increase the γ-oryzanol content.

Enzymatic esterification/transesterification of rice bran acid oil for subsequent γ-oryzanol recovery

This study recovered γ-oryzanol from rice bran acid oil (RBAO), following an initial enzymatic esterification/transesterification to selectively convert its glyceride impurities into fatty acid ethyl esters (FAEEs) or biodiesel. γ-oryzanol was then deprotonated and separated from the biodiesel into the resulting aqueous phase via acid-base extraction. Herein, we determine the effects of varying reaction conditions, i.e., ethanol:RBAO molar ratio, temperature, reaction time, enzyme loading, and agitation speed, on the degrees of glyceride removal, γ-oryzanol loss, free fatty acid (FFA) remaining, and biodiesel content. Up to 100% glyceride removal was achieved with a relatively high biodiesel yield (84%) and γ-oryzanol loss as low as 26% under our most suitable reaction conditions (5:1 ethanol:RBAO molar ratio, 40 °C, 24 h reaction time, 10%wt enzyme loading, 200 rpm agitation). Furthermore, of the remaining oryzanol, up to 94% was recovered by the acid-base extraction with 2-4 M ethanolic NaOH solution. Our results suggest that a combination of enzymatic esterification/transesterification with subsequent acid-base extraction offers an efficient alternative approach to the simultaneous production of biodiesel and γ-oryzanol recovery from low-cost RBAO. Based on our analysis of techno-economic and environmental sustainability, integration of the present method into a rice bran oil refinery would make the process profitable, with the minimum use of toxic chemicals and energy.

Enzymatic hydrolysis as a green alternative for glyceride removal from rice bran acid oil before γ-oryzanol recovery: Statistical process optimization

Rice bran acid oil (RBAO) is a byproduct of rice bran oil refinery, comprising of free fatty acids (FFAs), glycerides, and considerable amount of the natural antioxidant, γ-oryzanol. As a primary step to recover γ-oryzanol from RBAO, glycerides must be removed by conversion into more easily separable components such as FFAs. In this study, enzymatic hydrolysis was proposed as a green alternative to conventional base-catalyzed hydrolysis for glyceride removal from RBAO. The face-centered central composite rotatable design was used to investigate the effects of three independent variables: time, temperature, and water:RBAO ratio, and their interactions on the responses: glyceride removal, γ-oryzanol loss, and FFA production, and to determine the statistical models describing their relationships. In addition, by applying the desirability function approach, the optimal location was identified, corresponding to maximal glyceride removal with an imposed upper limit of 35% γ-oryzanol loss. At an established optimal condition of 22 h, 48.5 °C and 1:1 water:RBAO ratio, the experiments in which the enzymatic hydrolysis was carried out at 1x and 10x reaction scales confirmed the validity of the models: glyceride removal approached completion (99%), γ-oryzanol loss was as low as 32%, and the FFA production was 73–75%, falling within the 95% prediction interval. The results of this study demonstrated that the enzymatic hydrolysis is a promising method for glyceride removal prior to recovery of γ-oryzanol from RBAO, and that the statistical models gave accurate predictions of responses and would be useful further industrial design of the process.

Method Development for Purification of γ-oryzanol from Hydrolyzed Rice Bran Acid Oil by Semi-preparative Chromatography.

The objective of this study was to develop a method for isolation and purification of γ-oryzanol from hydrolyzed rice bran acid oil (RBAO) using semi-preparative chromatography by first applying silica coated-thin layer chromatography (TLC) to determine the suitable mobile phase. Subsequently, column chromatography was carried out to determine the effects of purification conditions such as the amount of and particle sizes of the sample silica gel, and elution modes, on the percentage of γ-oryzanol yield and recovery. The results from the TLC suggested that 75:25 (v/v) hexane to ethyl acetate mixture was a suitable mobile phase. The semi-chromatographic results indicated that the column containing 10 g of 25-40 μm silica gel with isocratic elution gave the highest yield (84%) of purified γ-oryzanol (> 95% purity). Further application of a step-gradient elution with 85:15 (v/v), followed by 75:25 (v/v) hexane to ethyl acetate mixture increased chromatographic resolution (Rs), resulting in enhanced separation efficiency, which in turn led to a higher yield of purified γ-oryzanol of 90%.

Ruminal degradability of bypass fat and protein of certain commonly used feedstuffs in dairy rations

Studies were conducted to determine the rumen degradability of protein of certain commonly used feed ingredients and degradability of bypass fat used in dairy rations. In situ crude protein (CP) disappearance of groundnut cake, soybean extraction, cottonseed cake, maize gluten meal, wheat bran, rice bran, maize, 0.3, 0.6 and 0.9% (of CP) formaldehyde treated soybean extraction, and in situ fat disappearance of bypass fat in the rumen at different incubation periods were determined by nylon bag technique using 3 adult crossbred steers. The effective degradability was calculated for an assumed outflow rate of 5%/h. The effective CP degradability of groundnut cake, soybean extraction, cottonseed cake, maize gluten meal, wheat bran, rice bran, maize, 0.3, 0.6 and 0. 9% (ofCP) formaldehyde treated soybean extraction was 86, 74, 66, 21, 73, 65, 63, 66, 48 and 26%, respectively. The effective fat degradability of bypass fat was 86%. The results indicated that maize gluten meal is a good source of bypass protein. Soybean extraction although extensively degraded in the rumen, contribute fairly more amount of undegradable protein than rumen degradable protein at an outflow rate of 5%/h, when it is treated with 0.6 and 0.9% (of CP) formaldehyde. The bypass fat supplement prepared from rice bran acid oil is a good source of energy in which about 86% of fat would be available at the lower tract of ruminants. Therefore, maize gluten meal, 0.9% formaldehyde treated soybean extraction and protected fat can be included in the rations of dairy animals forimproved productive performance

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Grain bran is used mostly in animal farming and food industry. However, grain bran can also serve as an alternative source of nitrogenous substances in distillate technology. The present research objective was to study the complex of water-soluble nitrogenous compounds in grain bran and to identify the effect of the bran type and its granulometric characteristics on their composition and concentration. 
 The research featured 30 industrial grain samples of wheat, rye, and triticale, as well as the corresponding bran samples. The total protein was determined by the Kjeldahl method, the size modulus – by sieving. In the bran aqueous phase, the protein content was measured using the Lowry method, the amine nitrogen content – by the copper method, and the free amino acid content – by the high-performance liquid chromatography. 
 In bran, the content of total protein increased by 16–28%, the proportion of water-soluble forms of nitrogenous compounds increased by 6–29%, and the free amino acids increased by 1.4–2.3 times, if compared with the grain samples. The proportion of soluble proteins in the rye bran was 15–30% higher than in other types. The types of bran had a different content of individual amino acids. A high correlation was observed between the modulus of the bran size, the mass concentration of soluble proteins, and the free amino acids. The proportion of soluble proteins reached 44.1% as the size modulus decreased. The samples of rye bran demonstrated the maximal growth of this indicator. Bran, regardless of the type of raw material and particle size distribution, had a higher concentration of free amino acids in comparison with the original grain. The experiment revealed the following linear dependence: the proportion of free amino acids in bran increased by 46–54% as the size modulus decreased by 0.72–0.85. The article introduces linear dependence equations for each type of bran, as well as the percentage of free amino acids for the change in the size modulus per unit. 
 Aqueous extracts of small-size rye grain bran proved to have good prospects for distillate technology. According to the evaluation of the nitrogen-containing complex of various grain bran types, small-size rye bran had more advantages in terms of soluble protein forms and free amino acids. Further research will feature the fermentation activity of yeast in distillate production to develop specific sensory properties.

Production of β-glucan exopolysaccharide lasiodiplodan by Lasiodiplodia theobromae CCT 3966 from corn bran acid hydrolysate.

The potential utilization of corn bran acid hydrolysate (CBAH) was evaluated as an inexpensive feedstock for the production of a rich carbohydrate and protein medium for lasiodiplodan (LAS) production using the filamentous fungus Lasiodiplodia theobromae CCT 3966. Experiments were performed according to a 22 CCRD experimental design aiming to evaluate the influence of agitation speed (rpm) and temperature (°C) over the production of total cell biomass (TCB) and LAS concentration released to the medium (LAS-M), adhered to biomass (LAS-C), and total (LAS-T). Under the selected conditions (temperature of 28°C and agitation of 200 rpm), 8.73 g·L-1 of LAS-T and 4.47 g·L-1 of TCB were obtained. Recovery of LAS-C with hot water was shown as an alternative to increase the production concentration, although it might require further purification steps. CBAH potential for substitution of synthetic media was demonstrated, indicating that it is an adequate raw material containing all necessary nutrients for LAS production.Key points• Corn bran acid hydrolysate is presented as a suitable substrate for β-glucan production.• Lasiodiplodia theobromae CCT 3966 have the potential for the industrial β-glucan production.• Simple recovering of biomass-adhered lasiodiplodan by hot water extraction.

A New Approach for the Production of Selenium-Enriched and Probiotic Yeast Biomass from Agro-Industrial by-Products in a Stirred-Tank Bioreactor.

The production of biomolecules using agro-industrial by-products as feedstock is a growing trend worldwide. Selenium (Se) is a trace element essential for health, and the Se-enrichment of yeast biomass can enhance its benefits. This study investigated the feasibility of the production of Saccharomyces cerevisiae Se-enriched biomass using a medium composed of corn bran and soybean bran acid hydrolysates as carbon and nitrogen sources in a stirred-tank reactor. After hydrolysis, hydrolysates presented complex composition and high concentrations of sugars, proteins, and minerals. The use of a stirred-tank bioreactor leads to the production of 9 g/L S. cerevisiae biomass enriched with 236.93 μg/g Se, and 99% cell viability. Likewise, the combination of sugarcane molasses and soybean bran hydrolysate was effective for cell growth of a probiotic strain of S. cerevisiae with a 24.08% β-glucan content. The results demonstrated that starchy acid hydrolysates are low-cost and efficient substrates for the production of yeast biomass and derivate products and may contribute to further studies for a sustainable development of biorefinery technologies.

Comparative study on physicochemical hydrolysis methods for glycerides removal from rice bran acid oil for subsequent γ-oryzanol recovery

A comparative study on physicochemical hydrolysis methods, including acid-catalyzed, base-catalyzed, and subcritical water hydrolysis, for glycerides removal prior to subsequent γ-oryzanol purification from rice bran acid oil (RBAO), is presented. The effects of hydrolysis conditions on the residual levels of glycerides and γ-oryzanol in RBAO were first investigated for each method. It can be concluded that the acid-catalyzed hydrolysis was not a suitable hydrolysis method for this application as it provided a low glycerides conversion level of ca. 30% using 2 N H2SO4 at 80–100 °C, despite the long reaction time (> 60 min). For the base-catalyzed hydrolysis, 100% glycerides removal was achieved at the most suitable condition, which was suggested to be at 2.5 N NaOH, 90 °C and 5–10 min. At this condition, a relatively high residual level of γ-oryzanol of ca. 57–66% was obtained. For the subcritical water hydrolysis, the results suggested that γ-oryzanol was hydrolyzed more rapidly than glycerides, and the most suitable condition for subcritical water hydrolysis was at 220 °C for 10 min. At this condition, high glycerides removal of > 95% was achieved while the remaining amount of γ-oryzanol was still acceptable (50%).

Utilization of Wheat Bran Acid Hydrolysate by Rhodotorula mucilaginosa Y-MG1 for Microbial Lipid Production as Feedstock for Biodiesel Synthesis.

The lignocellulosic hydrolysate was used as the fermentation feedstock of Rhodotorula mucilaginosa Y-MG1 for the production of microbial lipids as the potential raw material for biodiesel synthesis. On synthetic media and under nitrogen-limiting condition, the Y-MG1 strain produces 2.13 g/L of lipids corresponding to 32.7% of lipid content. This strain was able to assimilate a wide range of substrates, especially C5 and C6 sugars as well as glycerol and sucrose. Fatty acid composition shows a divergence depending on the nature of used carbon source with a predominance of oleic acid or linoleic acid. An effective hydrolysis process, based on diluted acid treatment, was established for providing the maximum of fermentable sugars from different characterized lignocellulosic wastes. The highest yield of reducing sugars (56.6 g/L) could be achieved when wheat bran was used as the raw material. Hydrolysate detoxification step was not required in this study since the Y-MG1 strain was shown to grow and produce lipids in the presence of inhibitors and without the addition of external elements. Operating by controlled fed-batch fermentation yielded a dry biomass and oil yield of up to 11 g/L and 38.7% (w/w), respectively. The relative fatty acid composition showed the presence of increased levels of monounsaturated (66.8%) and saturated (23.4%) fatty acids in lipids of Y-MG1 grown on wheat bran. The predictive determination of biodiesel properties suggests that this oil may effectively be used for biodiesel production.

Recovery of γ-Oryzanol from Rice Bran Acid Oil by an Acid-base Extraction Method with the Assistance of Response Surface Methodology.

A rapid and low energy consumption method for the recovery of γ-oryzanol from rice bran acid oil (RBAO), a byproduct of rice bran oil (RBO) refining, is presented. The RBAO was converted to the fatty acid ethyl ester (FAEE) and was used as the starting material. The dissolved γ-oryzanol was separated from the FAEE using an acid-base extraction method with alkaline aqueous ethanol and hexane as extraction media. A systematic investigation of the extraction yield was carried out by applying response surface methodology (RSM) based on central composite design (CCD) and Derringer's desirability function. The concentration of NaOH, the percentage of ethanol in water, the hexane content and their interactions showed significant effects on the yield of γ-oryzanol and FAEE. The optimal extraction conditions were as follows: extraction time of 1 min at room temperature (28-32°C); extraction medium: 1.855 M NaOH; 75.91% ethanol in water and 20.59% hexane in the total volume of the extractant; and FAEE to extractant ratio of 1:10 corresponding to a maximum γ-oryzanol yield of 75.82±3.44% and the desired FAEE yield of 54.42±7.80%. The γ-oryzanol-rich fraction was further purified by washing with a 2% Na2CO3 solution, obtaining 69.94% recovery yield with 89.90% purity of γ-oryzanol. The purified γ-oryzanol showed good scavenging activity on the 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical and the ABTS radical and was comparable to the commercial product, clearly suggesting that the presented process was efficient and feasible.

Potential Prebiotic Oligosaccharide Mixtures from Acidic Hydrolysis of Rice Bran and Cassava Pulp.

Two agricultural wastes, rice bran and cassava pulp were subjected to acidic hydrolysis by 2M sulfuric acid which resulted in hemicellulosic oligosaccharide mixtures. Monosaccharide component analysis of these mixtures revealed that the oligosaccharides of rice bran acid hydrolysate (RAHF) composed of glucose and arabinose while cassava pulp acid hydrolysate (CAHF) was found to be comprised of glucose, galactose and arabinose. Both RAHF and CAHF were able to fuel all of the tested threeLactobacillus, five Bifidobacterium and three Bacteroides strains indicating the prebiotic potential of these oligosaccharide mixtures. Moreover, Lb. gasseri grew significantly better on RAHF than on inulin, a benchmark prebiotic oligo- and polysaccharide mixture. When the digestibility of RAHF and CAHF were tested it was found that these oligosaccharide mixtures were only slightly hydrolyzed upon exposure to simulated human gastric (by less than 8%) and pancreatic juices (by less than 3%). Additionally, most sensory attributes of the above obtained oligosaccharide mixtures supplemented two model cereal drink formulations were generally not different from those of the control, while the overall acceptance was not affected significantly in one cereal drink formulation.

Changes in the phytochemical profile of rye bran induced by enzymatic bioprocessing and sourdough fermentation

Rye bran is a rich source of phytochemicals, such as alkylresorcinols, benzoxazinoids, and phenolic acids, which likely are attributing to the positive health effects of whole-grain foods. In this study, we examined the effect of two types of bioprocessing of rye bran on the phytochemical profile as compared with non-processed rye bran, using a non-targeted LC–MS metabolomics method. The four breads included in the study were commercial sourdough rye bread baked with 100% rye flour, a white wheat bread, a white wheat bread fortified with native rye bran, and a white wheat bread fortified with bioprocessed rye bran. The changes induced by the combination of enzymatic processing and yeast fermentation in the phytochemical pool were dissimilar to sourdough fermentation. Notably, the amount of free phenolic acids in bran was significantly increased, some of the hexose moieties were released from benzoxazinoids, and alkylresorcinols experienced moderate degradation. The enzymatic bioprocessing increased the bioaccessibility of several phytochemicals, thus making breads fortified with bioprocessed rye bran attractive targets of functional food development.

Structural Variation and Content of Arabinoxylans in Endosperm and Bran of Durum Wheat (Triticum turgidum L.).

Arabinoxylans are one group of dietary fiber components in cereal grains, and specific health benefits have been linked with their molecular fine structures and hence with physicochemical properties such as solubility in aqueous media. To characterize the fiber quality for functional foods, starchy endosperm and bran fractions from 11 durum wheat lines were analyzed for total and water-soluble arabinoxylans, (1,3;1,4)-β-glucan, and bound ferulic acid. The arabinoxylan contents ranged from 11 to 16.4% (w/w) in bran and from 1.5 to 1.8% in the starchy endosperm. Of the starchy endosperm arabinoxylans, 37% was soluble in water. No correlation was found between arabinoxylan content and bound ferulic acid in bran, although a relatively high level of this antioxidant was found in endosperm (38.3 μg/g endosperm flour). Enzymatic fingerprinting was performed to define the major fine structural features of arabinoxylans from both regions of the grain. Five major oligosaccharides released by xylanase hydrolysis were identified and characterized in the 11 durum lines. In addition, DP5, DP6, and DP7 oligosaccharides containing five, six, and seven pentosyl residues, respectively, were purified.

Effect of steam explosion-assisted extraction on phenolic acid profiles and antioxidant properties of wheat bran.

The majority of phenolic acids in wheat bran are bound to the cell walls. Hence, a high proportion of phenolic acids cannot be extracted with conventional extraction methods. This study aimed to investigate the efficiency of steam explosion pre-treatment in increasing the extractability of phenolic compounds from wheat bran. Bound phenolic acids (BPA) can be released by steam explosion-assisted extraction. Within the experimental range, soluble free phenolic acids (FPA) and soluble conjugated phenolic acids (CPA) increased gradually with residence time and temperature. After steam explosion at 215 °C for 120 s, the total FPA and CPA reached 6671.8 and 2578.6 µg GAE g(-1) bran, respectively, which was about 39-fold and seven-fold higher than that of the untreated sample. Ferulic acid, the major individual phenolic acids in bran, increased from 55.7 to 586.3 µg g(-1) for FPA, and from 44.9 to 1108.4 µg g(-1) for CPA. The antioxidant properties of FPA and CPA extracts were significantly improved after treated. Correlation analysis indicated that the antioxidant capacity was in close relationship with phenolic content in FPA and CPA. Steam explosion pre-treatment could be effectively used to release of BPA and enhance the antioxidant capacity of wheat bran. © 2015 Society of Chemical Industry.

Microwave-Assisted Extraction of Bound Phenolic Acids in Bran and Flour Fractions from Sorghum and Maize Cultivars Varying in Hardness

To release bound phenolic acids, a microwave-assisted extraction procedure was applied to bran and flour fractions obtained from eight sorghum and eight maize cultivars varying in hardness. The procedure was followed by HPLC analysis, and the identities of phenolic acids were confirmed by MS/MS spectra. The extraction of sorghum and maize bound phenolic acids was done for 90 s in 2 M NaOH to release ferulic acid and p-coumaric acid from bran and flour. Two diferulic acids, 8-O-4'- and 8-5'-benzofuran form, were identified and quantitated in sorghum bran, and only the former was found in maize bran. The contents of ferulic acid and diferulic acids in sorghum bran were 416-827 and 25-179 μg/g, respectively, compared to 2193-4779 and 271-819 μg/g in maize. Phenolic acid levels of sorghum were similar between hard and soft cultivars, whereas those of maize differed significantly (p < 0.05) except for ferulic acid in flour. Sorghum phenolic acids were not correlated with grain hardness as measured using a tangential abrasive decortication device. Maize ferulic acid (r = -0.601, p < 0.01), p-coumaric acid (r = -0.668, p < 0.01), and 8-O-4'-diferulic acid (r = -0.629, p < 0.01) were significantly correlated with hardness.

Amended Final Report on the Safety Assessment of Oryza Sativa (Rice) Bran Oil, Oryza Sativa (Rice) Germ Oil, Rice Bran Acid, Oryza Sativa (Rice) Bran Wax, Hydrogenated Rice Bran Wax, Oryza Sativa (Rice) Bran Extract, Oryza Sativa (Rice) Extract, Oryza Sativa (Rice) Germ Powder, Oryza Sativa (Rice) Starch, Oryza Sativa (Rice) Bran, Hydrolyzed Rice Bran Extract Hydrolyzed Rice Bran Protein,

This report addresses the safety of cosmetic ingredients derived from rice, Oryza sativa. Oils, Fatty Acids, and Waxes: Rice Bran Oil functions in cosmetics as a conditioning agent--occlusive in 39 formulations across a wide range of product types. Rice Germ Oil is a skin-conditioning agent--occlusive in six formulations in only four product categories. Rice Bran Acid is described as a surfactant-cleansing agent, but was not in current use. Rice Bran Wax is a skin-conditioning agent--occlusive in eight formulations in five product categories. Industry did not directly report any use of Rice Bran Wax. Hydrogenated Rice Bran Wax is a binder, skin-conditioning agent--occlusive, and viscosity-increasing agent--nonaqueous in 11 formulations in six product categories. Rice Bran Oil had an oral LD50 of > 5 g/kg in white rats and Rice Wax had an oral LD50 of > 24 g/kg in male mice. A three-generation oral dosing study reported no toxic or teratologic effects in albino rats fed 10% Rice Bran Oil compared to a control group fed Peanut Oil. Undiluted Rice Bran Oil, Rice Germ Oil, and Hydrogenated Rice Bran Wax were not irritants in animal skin tests. Rice Bran Oil was not a sensitizer. Rice Bran Oil, Rice Germ Oil, Rice Wax, and Hydrogenated Rice Bran Wax were negative in ocular toxicity assays. A mixture of Rice Bran Oil and Rice Germ Oil had a ultraviolet (UV) absorption maximum at 315 nm, but was not phototoxic in a dermal exposure assay. Rice Bran Oil was negative in an Ames assay, and a component, gamma-oryzanol, was negative in bacterial and mammalian mutagenicity assays. Rice oils, fatty acids, and waxes were, at most, mildly irritating in clinical studies. Extracts: Rice Bran Extract is used in six formulations in four product categories. Rice Extract is a hair-conditioning agent, but was not in current use. Hydrolyzed Rice Extract is used in four formulations and current concentration of use data were provided for other uses. Hydrolyzed Rice Bran Extract, described as a skin-conditioning agent--miscellaneous, is used in two product categories. Use concentrations are in the 1% to 2% range. Rice Bran Extract is comprised of proteins, lipids, carbohydrates, mineral ash, and water. The content includes palmitic, stearic, oleic, and linoleic acids. Other components include antioxidants such as tocopherols. Rice Extract reduced the cytotoxicity of sodium chloride in male rats. Bran, Starch and Powder: Rice Bran (identified as rice hulls) is an abrasive and bulking agent in one formulation. Rice Starch is an absorbent and bulking agent in 51 formulations across a wide range of product categories. Rice Germ Powder is an abrasive and one manufacturer described an exfoliant use, but it was not reported to be used in 2002. Oral carcinogenicity studies done on components of Rice Bran (phytic acid and gamma-oryzanol) were negative. Rice Bran did not have an anticarcinogenic effect on 1,2-dimethylhydrazine-induced large bowel tumors. In cocarcinogenicity studies done using 1,2-dimethylhydrazine and other agents, with Rice Bran Oil and Rice Bran-derived hemicellulose and saccharide, tumor inhibition was observed; gamma-oryzanol did not inhibit the development of neoplasms. A decrease in cutaneous lesions in atopic dermatitis patients was reported following bathing with a Rice Bran preparation. Proteins: Hydrolyzed Rice Bran Protein and Hydrolyzed Rice Protein function as conditioning agents (hair or skin), but only the latter was reported to be used in a few products. An in vitro phototoxicity assay using UVA light found no photochemical toxicity. Rice bran protein hydrolysates are not acutely toxic, are not skin or ocular irritants in animals, are not skin sensitizers in guinea pig maximization tests, and are not irritating or sensitizing in clinical tests. Isolated cases of allergy to raw rice have been reported, but rice, in general, is considered non allergenic. The Cosmetic Ingredient Review (CIR) Expert Panel considered that safety test data available on certain of these ingredients could be extrapolated to the entire group. Although Rice Bran Extract does contain UV absorbing compounds at low concentrations, clinical experience suggested no phototoxicity would be associated with such materials. Rice derived ingredients generally are considered to be non allergenic. There were no safety test data available for Hydrolyzed Rice Extract and Hydrolyzed Rice Bran Extract, but their safety may be inferred from that of the extracts from which they are derived. Current levels of polychlorinated biphenyls (PCBs) and heavy metals in rice-derived ingredients used in cosmetics are not a safety concern. The Panel was concerned, however, that contaminants such as pesticides have been reported in Rice Bran Oil used for cooking. Pesticides and heavy metals should not exceed currently reported levels for rice-derived cosmetic ingredients. The CIR Expert Panel concluded that these rice-derived ingredients are safe as cosmetic ingredients in the practices of use and concentrations as described in this safety assessment.

Antioxidant and antimicrobial effects of extracts from hydrolysates of lignocellulosic materials.

The antioxidant and antimicrobial activities of ethyl acetate extracts obtained from acid hydrolysates of several lignocellulosic materials (Eucalyptus globulus wood, barley bran, corn cobs, and corn leaves) were evaluated. The minimum inhibitory and bactericide concentrations (MIC and MBC, respectively) were determined against a selection of bacteria and yeasts. Extracts from Eucalyptus wood hydrolysates were the most active for inhibiting bacteria and yeast growth, with MIC in the range of 10(2)--5 x 10(3) microg/mL and MBC in the range of 10(3)--0(5) microg/mL. Bacteriogenic and bacteriostatic activities of extracts from Eucalyptus wood and barley bran acid hydrolysates were slightly higher than those of corn cobs and leaves. Both the radical scavenging capacity and the inhibition of the beta-carotene bleaching caused by extracts were determined and compared with those of synthetic antioxidants. The antioxidant activity of extracts increased with their concentrations in the media, the stronger properties corresponding to those obtained from Eucalyptus wood hydrolysates.

Isolation of γ-Oryzanol through Calcium Ion Induced Precipitation of Anionic Micellar Aggregates

A simple method for the isolation of γ-oryzanol from rice bran acid oil has been developed. The basis of the present isolation protocol is calcium ion induced precipitation of anionic micellar aggregates. Rice bran acid oil, a byproduct of rice bran oil processing industries, is subjected to conventional vacuum distillation to remove free fatty acids. Aqueous alkaline hydrolysis of the resultant residue, upon dilution with water, produces anionic micellar aggregates containing solubilized γ-oryzanol. Addition of calcium ions to this aqueous micellar aggregate induces instant coprecipitation of the calcium salts of the fatty acids and the aggregate-associated γ-oryzanol. The dried precipitate is extracted with ethyl acetate. Ethyl acetate is evaporated from the extract, and γ-oryzanol is purified from the residue by silica gel column chromatography. Experimental details for the isolation and characterization procedure are described. The present method will give ready access to the physiologically beneficial and value-added pharmaceutical product γ-oryzanol.