Showing papers on "Rice bran oil published in 2008"

Efficient Immobilization of Lecitase in Gelatin Hydrogel and Degumming of Rice Bran Oil Using a Spinning Basket Reactor

Abstract: Immobilization of Lecitase (Phospholipase A1) in gelatin hydrogel and its stability is studied with a view to utilizing the immobilized enzyme for degumming rice bran oil. Excellent retention of enzyme activity ((80%) is observed in hydrogel containing 43.5% gelatin crosslinked with glutaraldehyde. Compared to the free enzyme which has a broad pH-activity profile (6.5-8.0), the activity of the immobilized enzyme is strongly dependent on pH and has a pH-optimum of pH 7.5. The optimum temperature of enzyme activity increases from 37 to 50 C. Compared to the free enzyme which loses all its activity in 72 h at 50 C, the immobilized enzyme retains its activity in full. The immobilized enzyme has been used efficiently in a spinning basket bioreactor for the degumming of rice bran oil with 6 recycles without loss of enzyme activity. The phosphorus content of the oil decreases from 400 ppm to 50-70 ppm in each cycle. After charcoal treatment and dewaxing, a second enzymatic treatment brings down the phosphorus content to \5 ppm.

Preparation and Characterisation of Protein Hydrolysates from Indian Defatted Rice Bran Meal

Abstract: Rice bran meal is a very good source of protein along with other micronutrients. Rice bran meal has been utilized to produce protein isolates and respective protein hydrolysates for potential application in various food products. De-oiled rice bran meal, available from Indian rice bran oil extraction plants, was initially screened by passing through an 80-mesh sieve (yield about 70%). A fraction (yield-30%) rich in fibre and silica was initially discarded from the meal. The protein content of the through fraction increased from 20.8% to 24.1% whereas silica content reduced from 3.1% to 0.4%. Rice bran protein isolate (RPI) was prepared by alkaline extraction followed by acidic precipitation at isoelectric point. This protein isolate was hydrolysed by papain at pH 8.0 and at 37 degrees C for 10, 20, 30, 45 and 60 minutes. The peptides produced by partial hydrolysis had been evaluated by determining protein solubility, emulsion activity index (EAI), emulsion stability index (ESI), foam capacity and foam stability (FS). All protein hydrolysates showed better functional properties than the original protein isolate. These improved functional properties of rice bran protein hydrolysates would make it useful for various application especially in food, pharmaceutical and related industries.

Synthesis of Biodiesel from Mixed Feedstocks and Longer Chain Alcohols Using an Acid-Catalyzed Method

Abstract: Biodiesel is typically synthesized from triacylglycerides derived from seed oils (e.g., soybean) and an alcohol (e.g., methanol) with base catalysis, yielding the fatty acid methyl ester, biodiesel. Alternative oil feedstocks (e.g., used cooking oil, rice bran oil, and algae) often have significant quantities of free fatty acids, which greatly complicate the synthesis of biodiesel using the base/methanol method. Here, we have explored a wide range of reaction conditions that optimize biodiesel production from mixed feedstocks containing high free fatty acids. To rapidly survey conditions, a microwave-heated reaction was used to accelerate the reaction and the product was quantified by (1)H nuclear magnetic resonance (NMR) spectroscopy. Conditions were determined that allowed for rapid and high yield conversion of oil feedstocks containing significant concentrations of free fatty acids into biodiesel using an acid-catalyzed reaction with longer chain alcohols (such as n-butanol) at a slight molar excess. The conditions were replicated in a traditional heating method, where biodiesel yields greater than 98% were achieved in less than 40 min. Key properties of the resulting butyl-diesel were determined, including cetane, pour point, and viscosity. The information presented should be valuable for the large-scale production of biodiesel from mixed feedstocks that are difficult to use by the base/methanol method.

Supercritical carbon dioxide extraction and deacidification of rice bran oil

Abstract: This study examined pilot-scale extraction and lab-scale deacidification of rice bran oil by using supercritical carbon dioxide (SC-CO2). Two purest gamma-oryzanols (γ-oryzanols) (>98 wt%) were initially obtained by preparative reverse-phase high-performance liquid chromatography. Supercritical carbon dioxide extraction at 300 bar and 313 K from 1.03 kg powdered rice bran indicated a total yield of oil of 15.7% with a free fatty acids content of 3.75%, obtained from 20.5 kg of carbon dioxide in 8 h. In the SC-CO2 deacidification, pressure ranged from 200 bar to 300 bar, temperature ranged from 343 K to 363 K and consumption of carbon dioxide ranged from 900 g to 2700 g: the efficiency of removal of free fatty acids from 13 g extracted oil in deacidification at 250 bar and 353 K reached 97.8% using 2700 g of carbon dioxide. Finally, three-factor center composite scheme of response surface methodology was employed in designing a SC-CO2 deacidification system, which demonstrated that the pressure and consumption of carbon dioxide are significant in retaining triglycerides and in removing free fatty acids from rice bran oil.

Quality Changes and Tocopherols and γ-Orizanol Concentrations in Rice Bran Oil During the Refining Process

Abstract: The quality changes and the concentrations of tocopherols and γ-oryzanol, during successive steps of rice bran oil refining (RBO), were studied For this purpose, samples of crude, degummed, neutralized, bleached, dewaxed and deodorized RBO were taken from an industrial plant and analyzed The moisture, pH, acidity, peroxide value and unsaponifiable matter, were determined The fatty acid composition was evaluated by GC, and the concentrations of tocopherols and γ-oryzanol were determined using HPLC with fluorescence and UV–Vis detection, respectively To identify γ-oryzanol components, fractions of the HPLC eluant were collected and analyzed using mass spectrometry Oil refining reduced the peroxide value and acidity to 1 and 3% of the values obtained in crude RBO, respectively The fatty acid composition were not significantly altered during refining The concentrations of the tocopherols in RBO followed the order α > (β + γ) > δ The total concentration of tocopherols was 26 mg/100 g, and remained practically unaltered during refining Up to nine components were distinguished in γ-oryzanol After collecting the elution fractions, up to six components were identified by electrospray mass spectrometry Refining reduced the total concentration of γ-oryzanol to 2% of its initial value

Optimization of enzymatic degumming process for rice bran oil using response surface methodology

Abstract: Response surface methodology was used to determine the optimum processing conditions for enzymatic degumming of rice bran oil. Reaction time, enzyme dosage, level of water added and temperature were the factors investigated with respect to phosphorus and free fatty acids contents. A D-optimal design, with four variables and two response functions, was employed to study the effect of the individual variables on the response functions. For each response, second-order polynomial models were developed using multiple linear regression analysis. Applying desirability function method, optimum operating conditions were found to be reaction time of 4.07 h, enzyme dosage of 50 mg/kg, added water of 1.5 ml/100 g and temperature of 49.2 °C. At this optimum point, phosphorous and free fatty acids contents of degummed oil were found to be 8.86 mg/kg and 2.01 g/100 g as oleic acid, respectively.

Enzymatic transesterification of fractionated rice bran oil with conjugated linoleic acid: Optimization by response surface methodology

Abstract: Rice bran oil (RBO) was fractionated at a low temperature (−16 °C) and the yield of fractionated solid (S-RBO) and liquid (L-RBO) phase were 66.5 and 33.5 g/100 g, respectively. The L-RBO contained more unsaturated fatty acids (81.8%) than S-RBO (76.1%). Response surface methodology (RSM) was used to determine the effects of three variables (water activity of lipase, reaction temperature and time) on the lipase catalyzed incorporation of conjugated linoleic acid (CLA) into L-RBO. We used CLA as the acyl due to its purported health benefits. The transesterified lipid (TL) contained palmitic (13.5%), oleic (37.5%), linoleic (26.6%) and CLA isomers (20.7%), respectively. According to ridge analysis, optimal reaction conditions for water activity of lipase, reaction temperature and time were 0.177, 55.66 °C and 29.25 h, respectively, for producing TL with maximum incorporation of CLA. The coefficient of determination (R2=0.94) showed that the fitted model explained 94% of the observation. The TL was reproduced to confirm the experimental incorporation with the estimated value. The data showed that the experimental response was reasonably close to the estimated response. These results suggested that RSM can be used to optimize lipase-catalyzed incorporation of CLA into the fractionated L-RBO.

Biodiesel from Rice Bran Oil: Transesterification by Tin Compounds

Abstract: The transesterification of rice bran oil with methanol has been studied in the presence of sulfuric acid (H2SO4), tin chloride dihydrate (SnCl2·2H2O), tin 2-ethylhexanoate (Sn(C8H15O2)2), dibutyl tin oxide ((C4H9)2SnO), and dibutyl tin dilaurate ((C4H9)2Sn(C12H23O2)2), known commercially as DBTDL. Through the comparative analysis among the catalysts, we observed that the complex DBTDL presented the best performance, with a yield of 68.9% in 4 h using molar ratio 400:100:1 (methanol:oil:catalyst). These results evidenced the viability of the use of metallic compounds as catalysts in the obtainment of biodiesel, an interesting alternative to basic and acid catalysis.

Designing supercritical carbon dioxide extraction of rice bran oil that contain oryzanols using response surface methodology.

Abstract: This study examines the supercritical carbon dioxide (SC-CO(2)) extraction of oryzanols contained rice bran oil from powdered rice bran. The extraction efficiencies and concentration factors of oryzanols, free fatty acids and triglycerides in the SC-CO(2) extracts were determined. With top-flow type SC-CO(2) extraction the total oil yield was 18.1% and the extraction efficiencies of oryzanols and triglycerides were 88.5 and 91.3% respectively, when 2750 g CO(2 )was consumed during the extraction of 35 g rice bran powder. The concentration factors of oryzanols and triglycerides in SC-CO(2)-extracted oil were higher than in the Soxhlet n-hexane extracted oil. SC-CO(2) extractions indicated that pressure can be used more effectively than temperature to enhance the extraction efficiency and concentration factor of oryzanols. A two-factor central composite scheme of response surface methodology was employed to determine the optimal pressure (300 bar) and temperature (313 K) for increasing the concentration of oryzanols in the SC-CO(2) extracted oil.

Production and Characterization of Functional Substances from a By-Product of Rice Bran Oil and Protein Production by a Compressed Hot Water Treatment

Abstract: A by-product of rice bran oil and protein production was treated with water and compressed hot water at 20 °C to 260 °C for 5 min, and at 200 °C and 260 °C for 5 to 120 min Each extract was evaluated for its yield, radical scavenging activity, carbohydrate, protein, total phenolic and furfural contents, molecular-mass distribution and antioxidative activity The maximum yield was obtained at 200 °C The radical scavenging activity and the protein, total phenolic and furfural contents of the extract increased with increasing temperature However, the carbohydrate content abruptly decreased when treated at above 200 °C The extract treated at 260 °C for 5 min exhibited suppressive activity toward the autoxidation of linoleic acid Each extract obtained at temperatures lower than or equal to 200 °C exhibited emulsifying ability

Effects of Crude Rice Bran Oil Components on Alkali-Refining Loss

Abstract: The effects of minor components in crude rice bran oil (RBO) including free fatty acids (FFA), rice bran wax (RBW), γ-oryzanol, and long-chain fatty alcohols (LCFA), on alkali refining losses were determined. Refined palm oil (PO), soybean oil (SBO) and sunflower oil (SFO) were used as oil models to which minor component present in RBO were added. Refining losses of all model oils were linearly related to the amount of FFA incorporated. At 6.8% FFA, the refining losses of all the model oils were between 13.16 and 13.42%. When <1.0% of LCFA, RBW and γ-oryzanol were added to the model oils (with 6.8% FFA), the refining losses were approximately the same, however, with higher amounts of LCFA greatly increased refining losses. At 3% LCFA, the refining losses of all the model oils were as high as 69.43–78.75%, whereas the losses of oils containing 3% RBW and γ-oryzanol were 33.46–45.01% and 17.82–20.45%, respectively.

Rice bran first-level oil refinement production method

Abstract: The present invention relates to a manufacturing method of refining rice bran top oil, which can effectively refining top oil from the rice bran and satisfy the people requirement to the health dieting. The invention includes the following steps: (1) crude oil filtering; (2) phosphoric acid degumming and light alkali alkali refining; (3) washing, drying; (4) dewaxing; (5) a primary decolorizing; (6) physical deacidification; (7) secondary alkali refining; (8) iron removing; (9) washing; (10) drying; (11) secondary decolorizing; (12) deodorization; (13) degreasing. The invention adopts a mode of combining the physical refining and chemical refining to realize a large-scale production of the rice bran top oil, provides a favorable technique to the rice bran deep-processing, improves the extraction rate from traditionally 55-60% to 75-80%, saves materials and reduces environmental pollution, has huge economic and social benefits. The invention is a major innovation to the edible rice bran oil production.

Edible mixed oil

Abstract: The invention relates to an edible blend oil, which aims at solving the problem of the improper ratio between Omega-6 polyunsaturated fatty acid and Omega-3 polyunsaturated fatty acid in the current single plant edible oil and provides an edible plant blend oil with the ratio between Omega-6 polyunsaturated fatty acid and Omega-3 polyunsaturated fatty acid being the best, meeting the health need of Chinese residents and simultaneously being capable of controlling the amount and stability of saturated fatty acids. The technical keys are as follows: the edible blend oil is prepared with a hemp seed oil and another edible plant oil or other edible plant oils according to weight percentage; wherein, the hemp seed oil is 8 to 85 and the edible plant oil is 15 to 92; and the other edible plant oil can be as follows: grape seed oil, olive oil, camellia oil, rice bran oil, safflower oil, canola oil, sunflower oil, corn oil, linseed oil, sesame oil, rapeseed oil, soybean oil, peanut oil and other edible plant oils. The content of the saturated fatty acids does not exceed 15 percent and the ratio between Omega-6 and Omega-3 is 4-6:1.

Research Articles : Cholesterol-Lowering Efficacy of Unrefined Bran Oil from the Pigmented Black Rice (Oryza sativa L cv. Suwon 415) in Hypercholesterolemic Rats

Abstract: The effects of dietary supplementation of the unrefined rice bran oil from ``Suwon 415`` pigmented black rice (BRBO) on cholesterol metabolism and cellular antioxidant status were investigated in hypercholesterolemic rats. The significant reduction of total cholesterol (TC) and low density lipoprotein cholesterol (LDL-C) concentrations was observed in the plasma of rats fed BRBO. BRBO also decreased plasma and hepatic oxidative stress as a result of increased levels of hepatic thiobarbituric acid reactive substances (TBARS) levels associated with the elevations of hepatic superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GSH-Px) activities together with increased plasma level of tocopherol. This study indicates that dietary BRBO supplement can leads to the improvement of overall cholesterol metabolism and antioxidant status even more effectively than ``Chuchung`` white rice (WRBO). Consumption of BRBO may also protect the liver from oxidative damage caused by lipid peroxidation.

Cholesterol-lowering efficacy of unrefined bran oil from the pigmented black rice (Oryza sativa L cv. Suwon 415) in hypercholesterolemic rats

Abstract: The effects of dietary supplementation of the unrefined rice bran oil from ‘Suwon 415’ pigmented black rice (BRBO) on cholesterol metabolism and cellular antioxidant status were investigated in hypercholesterolemic rats. The significant reduction of total cholesterol (TC) and low density lipoprotein cholesterol (LDL-C) concentrations was observed in the plasma of rats fed BRBO. BRBO also decreased plasma and hepatic oxidative stress as a result of increased levels of hepatic thiobarbituric acid reactive substances (TBARS) levels associated with the elevations of hepatic superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GSH-Px) activities together with increased plasma level of tocopherol. This study indicates that dietary BRBO supplement can leads to the improvement of overall cholesterol metabolism and antioxidant status even more effectively than ‘Chuchung’ white rice (WRBO). Consumption of BRBO may also protect the liver from oxidative damage caused by lipid peroxidation.

The effect of vegetable fat on the physicochemical characteristics of dates ice cream

Abstract: The effects of vegetable fats in low-calorie dates ice cream were studied. Fourteen different formulations were optimized by ‘simplex lattice design’. Three types of fat (palm mid-fraction, palm olein and rice bran oil) were chosen to investigate their particle size distribution, melting resistance, amount of protein in the aqueous phase, colour, viscosity, total solids, percentage of overrun, fat and calorie value in ice cream. Statistical significance was determined by using analysis of variance and compared with the Duncan multiple range test using the SAS program. The significance level was 95% (P = 0.05). The types of fat used in an ice cream formulation have an impact on the colour, particle size diameter, viscosity and caloric value. A high percentage of palm mid-fraction (> 12%) gave a high intensity of brightness, but less redness and yellowness, while a high percentage of palm olein and rice bran oil gave high intensity of redness and yellowness. Moreover, viscosity was associated with formulations characterized by a high solid fat content. The more unsaturated and the longer the fatty acid chains of the vegetable fat used in the formulation, the more pronounced was the fat globule destabilization. However, the effect of the different fats on melting resistance was less pronounced.

The concentration of tocols from rice bran oil deodorizer distillate using solvent

Abstract: Tocols (tocopherols + tocotrienols) have been concentrated efficiently from rice bran oil (RBO) deodorizer distillate using solvent at low temperature. The levels of total tocols, total tocopherols, and total tocotrienols in RBO deodorizer distillate (starting material) were 31.5, 14.9, and 16.6 mg/g, respectively. Nine different solvents were tested, and acetonitrile was selected as the optimal solvent for concentrating tocols from the RBO deodorizer distillate. There was a significant (p <0.05) increase in the tocol level of the liquid fractions with decreasing temperature, for incubation temperatures up to -20 °C. In addition, significant differences (p <0.05) were observed in the relative percentages of α-tocopherol, γ-tocopherol, α-tocotrienol, and γ-tocotrienol between the raw sample and liquid fractions obtained at different temperatures using acetonitrile as the solvent. The concentration of the tocols from the RBO deodorizer distillate was temperature dependent, and a maximum of 89.9 mg/g was attained in the liquid fraction at - 40 °C. The relative percentage of tocotrienol homologs in the liquid fraction obtained at - 40 °C was approximately 80%. With acetonitrile as the solvent, the optimal temperature for concentrating the tocols from RBO deodorizer distillate was -20 °C when yield was considered.

Enriching oryzanol in rice bran oil using membranes.

Abstract: Oryzanol present in rice bran is associated with various physiological functions. However, these beneficial ferulate esters are lost to the extent of 87% during conventional refining of crude rice bran oil. In the present investigation, oryzanol enrichment in rice bran oil was attempted using nonporous polymeric membranes under undiluted as well as hexane-diluted conditions with different (crude, refined, and model oil) systems varying widely in their oryzanol content. During membrane processing, oryzanol content in the refined rice bran oil increased from 2,420 to 7,340 mg/kg (approximately threefold enrichment). While processing crude oil and model oil systems, the oryzanol content in the oil improved from 17,600 to 27,300 mg/kg and 20,400 to 30,300 mg/kg, respectively. The enrichment of oryzanol was due to its moderate rejection by the nonporous hydrophobic membrane owing to the hydrophilic nature of the ferulic esters. Hexane dilution improved the oil flux by one order of magnitude but reduced the selectivity. Enriched rice bran oil may find wider applications in the pharmaceutical, therapeutic, and dietary preparations as well as in producing standard cooking oil with guaranteed oryzanol content.

Feed mixed emulsifying oil and its producing method

Abstract: The present invention relates to a mixed emulsified oil for feed The described mixed emulsified oil is made up by using corn oil, soybean oil, coconut oil, palm oil, peanut oil, rice bran oil, cotton seed oil and hydroxylated modified soybean lecithin according to a certain mixing ratio through a certain preparation process Said invention also provides the concrete steps of its preparation process

Structured lipids from rice bran oil and stearic acid using immobilized lipase from Rhizomucor miehei

Abstract: The major objective of the present study was to prepare structured lipids rich in stearic acid from rice bran oil (RBO) using immobilized lipase (IM 60) from Rhizomucor miehei. The effects of incubation time and temperature, substrate molar ratio, and enzyme load on incorporation of stearic acid were studied. Acidolysis reactions were performed in hexane. Pancreatic lipase-catalyzed sn-2 positional analysis and tocopherol analyses were performed before and after enzymatic modification. The kinetics of the reaction was studied and maximum incorporation of stearic acid was observed at 6 h, at 37 7C, when the triacylglycerol and stearic acid molar ratio was maintained at 1 : 6 and the enzyme concentration was 10% of total substrates weight. Stearic acid in RBO after acidolysis was increased from 2.28 to 48.5%, with a simultaneous decrease in palmitic, oleic and linoleic acids. HPLC analysis of tocopherols and tocotrienols was carried out and their content in modified RBO was not significantly affected compared to that of native RBO. The oryzanol content of the modified RBO was reduced from 1.02 to 0.68%. Melting and crystallizing characteristics of the modified fat were studied using differential scanning calorimetry. The total solid fat content at 25 7C increased from 26.12 to 34.8% with an increase in stearic acid incorporation into RBO from 38 to 48%, but it was comparatively less than for cocoa butter and vanaspati. However, the modified RBO completely melted at 37 7C and was useful as plastic fat for various culinary purposes, bakery and confectionary applications. The results of the present study indicated that structured lipids prepared from RBO rich in stearic acid retained their beneficial nutraceuticals; in addition, they do not contain any trans fatty acids.

Rice bran-like composition and food

Abstract: A rice bran-like composition having higher bioactivity is provided by modifying rice bran. A rice bran-like composition contains a mixture of (1) defatted rice bran obtained by pressing rice bran to remove oil and (2) rice bran oil obtained by refining pressed rice bran oil, wherein a weight ratio of defatted rice bran content to rice bran oil content is 85:15 to 60:40. A food contains (1) defatted rice bran and (2) rice bran oil in a weight ratio of 85:15 to 60:40. Preferable components of the rice bran-like composition are as follows: the fat content is 20 to 40 wt.%, the protein content is 10 to 17 wt.%, the carbohydrate content is 5 to 21 wt.%, the ash content is 7 to 13 wt.%, and the fiber content is 20 to 32 wt.%. The present invention provides an effect of reducing or suppressing an increase in visceral fat; an effect of reducing or suppressing an increase in neutral fat in blood; and an effect of reducing or suppressing an increase in blood cholesterol, all the effects being superior to those of rice bran.

Method for synthetically extracting active matters in rice bran with separation technique

Abstract: A method for synthetically extracting the active substance in rice bran by using a separation technique includes: firstly extracting vegetative ceramide, extracting in order according to the physicochemical properties of the active substance from the filter residue after extracting vegetative ceramide, which comprises obtaining the rice bran protein using the isoelectric acid precipitation method, respectively obtaining the other active substances of the rice bran protein, the rice bran polysaccharide, the phytic acid and the rice bran oil by the organic solvent fractional precipitation, ion exchange resin and organic solvent extraction method. The method makes the best of biological resources, reduces the waste pollution in the production, and has better economic benefit.