Extraction Of Rice Bran Oil Research Articles

Effects of ultrasonication and thermal cooking pretreatments on the extractability and quality of cold press extracted rice bran oil

AbstractThis research investigates the effects of different extraction processes on the extractability and quality of rice bran oil. The extraction processes included hexane extraction (HE) as Control 1, cold press extraction (CE) as Control 2, ultrasonic pre‐treatment combined with cold press extraction (UCE), and thermal cooking combined with cold press extraction (CCE). The results showed that oil extractability was positively correlated to ultrasonic power and duration; and to thermal cooking time. Meanwhile, the oil quality and ultrasonic intensity and thermal cooking period were inversely correlated. Specifically, the oxidative stability, and unsaturated fatty acids of short‐period CCE oil were significantly higher than those of long‐period CCE oil and higher‐power and longer‐duration UCE oil. Similar to HE and CE oils, oleic, linoleic, and palmitic acids were the dominant fatty acids in short‐period CCE oil. Essentially, short‐period CCE is optimal for rice bran oil extraction due to improved oil extractability and quality.Practical applicationsRice bran oil is an excellent source of unsaturated fatty acids and natural antioxidants. It also has many proven health benefits. There are two conventional production methods of rice bran oil: pressing and solvent extraction. While the pressing method achieves low oil extractability, solvent extraction could deteriorate the oil quality. This research, thus, proposes two chemical‐free extraction techniques for rice bran oil that improves the oil extractability and preserves the oil quality: ultrasonic pretreatment combined with cold press extraction (UCE) and thermal cooking pretreatment combined with cold press extraction (CCE). The findings are expected to offer a possible solution to the extractability‐quality challenges associated with the conventional extraction methods.

Nutraceuticals from barley flour, flaxseed and rice bran oil-Extraction, chromatographic analysis, microbiological analysis and pesticide estimation

In the present study, barley flour, flaxseed and rice bran oil were utilized for the extraction of pivotal nutraceuticals like beta-glucans, lignans and gamma oryzanol concentrate, respectively, followed by their characterization on several parameters. Beta-glucan fibres isolated from six-rowed hull-less barley variety (HBL-276) by alkaline treatment followed by precipitation with ethanol revealed high beta-glucan content (65.74 ± 1.02/100 g). The flaxseed lignan concentrate and gamma oryzanol concentrate upon chromatographic analysis yielded high secoisolariciresinol diglucoside content (30 mg/g) and detected four major components of oryzanol (cycloartenyl ferulate, 24-methylenecycloartanyl ferulate, campesteryl ferulate and β-sitosteryl ferulate), respectively. The GC/MS analysis for pesticide estimation in raw materials did not show the presence of any pesticide which led to the safe utilization of these raw materials for extraction. In microbiological analysis of the three isolates, gamma oryzanol concentrate revealed the lowest total plate count, yeast and mould count and coliform count as well. Practical applications The nutraceuticals selected in this study have tremendous health as well as medicinal benefits. These impart immense protection against chronic and degenerative diseases like cardiovascular diseases and cancer. Incorporation of these isolated ingredients having health and nutritional properties into various food formulations can impart significant health benefits primarily reduction in blood serum low-density lipoprotein (LDL) cholesterol level, prevention in diseases like diabetes and cardiovascular diseases, minimizing atherosclerosis, etc. These isolates exhibited fairly less contamination with respect to microbiological analysis. Hence, including these isolated nutraceuticals into food products can be one of significant attempts towards the development of safe functional foods.

Solid liquid extraction of rice bran oil using binary mixture of ethyl acetate and dichloromethane

The aim of the study is to investigate the potentials of less hazardous, binary mixtures of ethyl acetate (EA) and dichloromethane (DCM) for rice bran oil recovery. Nine solvent mixtures are used with different volumetric ratios of EA/DCM ranging from 0.11 to 9. Solvent mixture with volumetric ratio of 4 (S8) has enabled the maximum oil recovery 88.04 %. The oil extraction yield is enhanced from 76.41 to 89.7 % by increasing the preheating temperature from 40 to 65?C. The other optimized parameters for enhanced oil recovery are: bran particle size <125 ?m (obtained with 120 mesh sieve), solvent to bran ratio of 5 mL/g, and stirring time of 15 min. The minimum stirring rate for preventing agglomeration in the mixture and optimized oil recovery is 80 rpm.

Some Strategies for Utilization of Rice Bran Functional Lipids and Phytochemicals.

Rice bran contains a great amount of functional lipids and phytochemicals including γ-oryzanols, tocotrienols, and tocopherols. However, utilization of those compounds is limited and needs some proven guidelines for better implementation. We introduce some effective strategies for the utilization of rice functional lipids, including an introduction of pigmented rice varieties for better bioactive compounds, biofortification of rice tocotrienols, plasma technology for improving rice phytochemicals, supercritical CO2 extraction of high quality rice bran oil, and an example on the development of tocotrienol-fortified foods.

Comparative evaluation of rice bran oil obtained with two-step microwave assisted extraction and conventional solvent extraction

In the present study, an innovative approach for microwave assisted solvent extraction of rice bran oil (RBO) in two steps termed two-step microwave assisted extraction (TSMAE) has been adopted. Microwave treatment and solvent washing were done alternately in two steps. The effect of microwave power (200, 320, 450, 560 W), microwave exposure time (30, 60, 90, 120 s) and solvent to bran ratio (1.6, 2.3, 3 mL/g) per step on percentage of oil recovery in TSMAE were evaluated. Bran milled at 3–6% degree of polish was evaluated for oil recovery. Oil recovery of more than 95% was obtained in total extraction time of 8–10 min with only 1.6–2.3 mL/g solvent to bran ratio (per step). The overall oil quality obtained in TSMAE was found to be superior to that of conventional solvent extracted oil especially with respect to phospholipid content (0.64 ± 0.11 vs 1.02 ± 0.15%), α-tocopherol content (7.85 ± 0.19 vs 6.83 ± 0.12 mg/g RBO), antioxidant activity (1.50 ± 0.05 vs 1.27 ± 0.08 trolox equivalent antioxidant activity) and free fatty acid content (4.88 ± 0.26 vs 5.77 ± 0.25%). Microstructure analysis revealed cell rupture due to microwave treatment that suggests the reason for faster oil extraction in TSMAE.

Rice bran oil extraction using alcoholic solvents: Physicochemical characterization of oil and protein fraction functionality

Rice bran, an underutilized rice processing by-product, is a promising source for food and biodiesel oil production and can also be used to produce protein for use in human food products. The main objective of this study was to assess the feasibility of replacing hexane, which is traditionally used to extract vegetable oils, with safer solvents, i.e., ethanol and isopropanol, in rice bran oil (RBO) extraction. Thus, the effects of the solvent type on the physicochemical characteristics of the oil and defatted bran products were studied. The results showed that the presence of water in the alcoholic solvents negatively affected the oil extraction; however, using absolute solvents in single-stage batch extractions at 80°C resulted in oil yields of up to approximately 80%. The solvent water content and process temperature strongly impacted the properties of the protein fraction; the nitrogen solubility index (NSI) decreased from approximately 40% for the absolute solvents to 17 and 15% for the aqueous ethanol and isopropanol, respectively, when the extraction was performed at 80°C. More of the minor nutraceutical compounds were transferred from the oleaginous matrix to the oil by aqueous ethanol than by hexane, yielding RBO with 1.53% γ-oryzanol and 769mg/kg tocotrienols. On the other hand, absolute isopropanol exhibited a higher tocopherol extraction capacity; RBO with a tocopherol content of 98.1mg/kg was obtained with this solvent. Based on these results, short-chain alcohols are promising alternatives to the conventional extraction solvent, because they enable high-quality protein fractions and oils to be obtained and add value to the rice production chain.

Experimental data and modeling of rice bran oil extraction kinetics using ethanol as solvent

ABSTRACTThe extraction kinetics of rice bran oil (RBO), free fatty acids (FFA), and oryzanol using ethanol (0 and 6.3 mass % of water) at 40°C–70°C were investigated. High extraction temperatures increased the yields of RBO and oryzanol by increasing the diffusivity of the solvent, regardless of its water content. Two models that permitted the estimation of mass transfer and diffusion coefficients were fitted to the oil extraction data with low average relative deviations (≤5.92%). The diffusion coefficient (1.93–7.46 × 10–10 m2∙s–1) increased with increasing temperature and decreasing hydration of the solvent.

Simulation and process design of continuous countercurrent ethanolic extraction of rice bran oil

The overwhelming majority of all vegetable oils is extracted using solvent extraction, and the most widely used solvent is hexane. However, the use of ethanol has attractive advantages, including low toxicity, good operational security, as well as being obtained from a biorenewable source. In this study, a multiple-batch solid-liquid extraction system has been successfully employed to simulate continuous countercurrent ethanolic extraction of rice bran oil. Results showed that the extraction process using ethanol as solvent is feasible and facilitated by increases in temperature. The number of equilibrium stages required for rice bran oil extraction was theoretically determined, and it was shown that in the extraction process using hexane the number of ideal stages is lower than the number required when ethanol is used as solvent. Furthermore, a mathematical expression for determining the minimum flow of solvent depending on the equilibrium relationship between the extract and raffinate phases has been developed and implemented for both solvents. Given the potential fire hazard and harmful emissions risks of using hexane as solvent, extraction with ethanol showed to be a promising alternative to conventional extraction, completely exhausting the solid matrix with only five stages.

Supercritical CO2 Extraction of Rice Bran Oil -the Technology, Manufacture, and Applications.

Rice bran is a good source of nutrients that have large amounts of phytochemicals and antioxidants. Conventional rice bran oil production requires many processes that may deteriorate and degrade these valuable substances. Supercritical CO2 extraction is a green alternative method for producing rice bran oil. This work reviews production of rice bran oil by supercritical carbon dioxide (SC-CO2) extraction. In addition, the usefulness and advantages of SC-CO2 extracted rice bran oil for edible oil and health purpose is also described.

Parametric optimization of rice bran oil extraction using response surface methodology

Abstract Use of bran oil in various edible and nonedible industries is very common. In this research work, efficient and optimized methodology for the recovery of rice bran oil has been investigated. The present statistical study includes parametric optimization, based on experimental results of rice bran oil extraction. In this study, three solvents, acetone, ethanol and solvent mixture (SM) [acetone: ethanol (1:1 v/v)] were employed in extraction investigations. Response surface methodology (RSM), an optimization technique, was exploited for this purpose. A five level central composite design (CCD) consisting four operating parameter, like temperature, stirring rate, solvent-bran ratio and contact time were examined to optimize rice bran oil extraction. Experimental results showed that oil recovery can be enhanced from 71% to 82% when temperature, solvent-bran ratio, stirring rate and contact time were kept at 55°C, 6:1, 180 rpm and 45 minutes, respectively while fixing the pH of the mixture at 7.1.

Extraction of rice bran oil using supercritical CO2 and compressed liquefied petroleum gas

This work focused on the extraction of rice bran oil using supercritical carbon dioxide (SC-CO2) and compressed liquefied petroleum gas (LPG). For the supercritical extractions, the influence of pressure and temperature on the extraction yield was evaluated from 150 to 250 bar and from 40 to 80 °C, whereas for compressed LPG extractions were performed at 5–25 bar and 20–40 °C. The antioxidant activity of the extracts was assayed by DPPH (2,2-diphenyl-1-picrylhydrazyl) radical scavenging method and the chemical composition by gas chromatography-mass spectrometry (GC–MS). The highest yields were 12.68 and 12.07 wt%, whereas the maximum antioxidant activities were 71.67 and 67.49% for extraction using SC-CO2 and compressed LPG, respectively. The chemical profile of fatty acids was similar for both solvents. The antioxidant compound found in both processes was the β-sitosterol, which is one of the components of γ-oryzanol. From kinetics analysis it was demonstrated that using LPG it is possible to decrease the solvent/feed mass by a factor of approximately 30, and extraction time by a factor of 15. Considering the slight difference in the yield and antioxidant activities of extracts between the solvents, compressed LPG is a more promising solvent than supercritical CO2 for extraction of rice bran oil, since the extraction period can be considerably reduced while lowering the energy required for solvent recompression.

The ultrasound-assisted aqueous extraction of rice bran oil

In this work, aqueous extraction of rice bran oil was done without and with ultrasound pretreatment. Key factors controlling the extraction and optimal operating conditions were identified. The highest extraction efficiency was found at pH=12, temperature of 45°C, agitation speed of 800rpm and agitation time of 15min, ultrasound treatment time of 70min and ultrasound treatment temperature of 25°C. Moreover, extraction yields were compared to ultrasound-assisted aqueous extraction and Soxhlet extraction. The results showed that the yield of rice bran oil at ultrasound-assisted aqueous extraction was close to the yield of oil extracted by hexane Soxhlet extraction. This result implied that the yield of rice bran oil was significantly influenced by ultrasound. With regard to quality, the oil extracted by ultrasound-assisted aqueous process had a lower content of free fatty acid and lower color imparting components than the hexane-extracted oil. Also, effect of parboiling of paddy on hexane and ultrasound-assisted aqueous extraction was studied. Both extraction methods gives higher percentage of oil from par boiled rice bran compared with raw rice bran. This may be due to the fact that parboiling releases the oil.

Modeling of Rice Bran Oil Yield and Bioactive Compounds Obtained Using Subcritical Carbon Dioxide Soxhlet Extraction (SCDS)

Subcritical carbon dioxide Soxhlet extraction (SCDS) is an innovative green technology that has been proven capable of extracting 10 times more bioactive compounds than hexane in rice bran oil extraction. As this technology has commercialization potential, understanding the extraction behavior and modeling the extraction curves are essential. In this study, the extraction kinetics of rice bran oil and its bioactive compounds, namely, α-, β-, γ-, and δ-tocopherol; α-, γ-, and δ-tocotrienol; and γ-oryzanol, are discussed and modeled using the diffusion model (DM), logistic model (LM), and simple single plate model (SSPM). Overall, the extraction rate of the oil yield and bioactive compounds was halved after 7 h of extraction. After 15 h of extraction, up to 94.24% of the extractable total tocopherol and 91.79% of the extractable total tocotrienol were extracted. The SSPM is recommended for modeling oil yield and oryzanol, while LM is suitable to model tocopherols and tocotrienols.

Effect of Subcritical Carbon Dioxide Extraction and Bran Stabilization Methods on Rice Bran Oil

AbstractThe extraction of rice bran oil using the conventional organic solvent‐based Soxhlet method involves hazardous chemicals, whereas supercritical fluid extraction is a costly high‐temperature operating system. The subcritical carbon dioxide Soxhlet (SCDS) system, which operates at a low temperature, was evaluated for the extraction of rice bran oil in this study. In addition, rice bran that had been subjected to steam or hot‐air stabilization were compared with unstabilized rice bran (control). The yields; contents of tocopherols, tocotrienols and oryzanol; fatty acid profiles; and the oxidative stabilities of the extracted rice bran oils were analyzed. The yields using hexane and SCDS extraction were approximately 22 and 13–14.5 %, respectively. However, oil extracted using the SCDS system contained approximately 10 times more oryzanol and tocol compounds and had lower free fatty acid levels and peroxide values compared with hexane‐extracted oil. Overall, SCDS extraction of steamed rice bran represents a promising method to produce premium‐quality rice bran oil.

FRAKSINASI KOMPLEKSASI UREA PADA MINYAK DEDAK PADI DALAM PENINGKATAN KONSENTRASI ASAM LEMAK TAK JENUH

<p>Abstract: Polyunsaturated fatty acid in rice bran oil is good for health and valuable. The aims of<br />this research were identifying influence of complexation temperature and time on the<br />enhancement of polyunsaturated fatty acid consentration. This research began with<br />saponification and extraction of rice bran oil as pretreatment process. Then, complexation<br />process was done with urea-ethanol solution ration of 35:175 (w/v). Complexation was carried<br />out by mixing 10 gram of free fatty acid of rice bran oil with 40 ml of urea-ethanol solution and<br />then followed by separation process and iod number analysis. The result of temperature<br />variation showed that the iod number of sample 0 hour, 2 hours, 12 hours, and 24 hours were<br />29.18; 32.99; 36.04; and 37.82. Then the iod number of sample with variable temperature 28<br />o<br />C, 5<br />o<br />C, -2<br />o<br />C and -7<br />C were 37.82; 39.85; 43.15; and 44.16. The longer time and the lower<br />temperature of complexation increased polyunsaturated fatty acid consentration indicated by iod<br />number rising.<br />o<br />Keywords: Rice bran oil, Polyunsaturated Fatty Acid, fractionation urea complexation, iod<br />number bixa</p>

Extraction of rice bran oil by supercritical carbon dioxide and solubility consideration

Among vegetable oils, rice bran oil has been considered to be one of the most valuable and healthy oil because it contains many nutraceutical components. In this work, extraction of oil and γ-oryzanol from crushed rice bran using supercritical carbon dioxide at various CO2 flow rate (1–9ml/min), temperatures (40–80°C) and pressures (20–40MPa) was investigated. The experimental extraction behavior was explained using two simple models of thermodynamic model and simple kinetic model. In addition, solubility data of rice bran oil in SCCO2 showed a good agreement with the values of the correlation of Chrastil model. The effect of extraction temperature and pressure on the γ-oryzanol recovery was studied.

The Concentrations of Tocols and ^|^gamma;-Oryzanol Compounds in Rice Bran Oil Obtained by Fractional Extraction with Supercritical Carbon Dioxide

Rice bran oil (RBO) is a good source of several commercially important bioactive phytochemicals, such as tocols (i.e. tocopherols and tocotrienols) and ferulic esters of sterols (i.e. γ-oryzanol). The aims of the present study were to examine the effects of different pressure and temperature combinations on the fractional extraction of RBO using supercritical carbon dioxide (SC-CO2) and to assess the levels of tocols homologues and γ-oryzanol components in the resulting oil fractions. Fractional extraction of rice bran oil was performed using SC-CO2 at either 27.6 or 41.4 MPa and either 40 or 60°C. The effects of the four different pressure and temperature combinations on the levels of seven tocols homologues (α-, β-, γ- and δ-tocopherol and α-, γ- and δ-tocotrienol) and the four major components of γ-oryzanol in the resulting oil fractions were investigated. Superior extraction efficiency was obtained using the higher pressure of 41.4 MPa. The tocols (particularly α-tocopherol and α-tocotrienol) were recovered early in the extraction process, while the γ-oryzanol compounds were obtained in the later stages. With regard to SC-CO2 extraction, tocols are more soluble than γ-oryzanol components, α-tocopherol is the most soluble of the tocols and the four γ-oryzanol components all have similar solubilities. Valuable data on solubilities of tocols homologues in SC-CO2 were provided from present study.

PRESSURIZED FLUID EXTRACTION OF RICE BRAN OIL USING A MODIFIED SUPERCRITICAL FLUID EXTRACTOR AND A CENTRAL COMPOSITE DESIGN FOR OPTIMIZATION

Rice bran is a by-product of rice processing, obtained through the polishing of rice grain. It illustrates the high considerable oil content (between 15–25%) and it is considered as an excellent source of nutritionally beneficial compounds. Pressurized fluid extraction (PFE) technique was used for extraction of oil from rice bran. The extracted samples planned by the central composite design were used to achieve 100% extraction yield under the following conditions. The temperature, pressure, extraction time and the solvent flow rate were adjusted 77°C, 75 bar, 34 min, and 0.2 mL/min, respectively. It is evident that free fatty acid content, iodine value and saponification value of the oil obtained by PFE is lower than hexane-extracted oil (Soxhlet). The results indicated that pressurized fluid extraction is a practical technique for extraction of rice bran oil.

Ohmic heating as a pre-treatment in solvent extraction of rice bran.

Rice bran, which is one of the major by products of paddy contain high quality proteins and edible oil apart from fibre, ash and NFE (nitrogen free extract). The existing solvent extraction method employs n-hexane as the most viable solvent for the extraction of oil from rice bran. But the high cost and scarce availability of n-hexane resulted in uneconomical extraction of rice bran oil. In this study, rice bran was ohmically heated for different time periods(1, 2 and 3min) with different current values (5, 15 and 20A) and with different concentration of sodium chloride (1M, 0.1M and 0.01M) as conducting medium. The ohmically heated rice bran was subjected to extraction studies. Ohmic heating of rice bran of paddy varieties Red Triveni and Basmati reduced the extraction time by nearly 75% and 70% respectively and gave a maximum quantity of oil extracted when compared to bran, which was not ohmically heated. From the experiments with varying concentrations, residence time of ohmic heating and currents, it was found that ohmically heating the rice bran with 1M sodium chloride solution and with a current value of 20A for 3min gave maximum oil extraction with minimum extraction time.

Rice Bran Oil Extraction by Screw Press Method: Optimum Operating Settings, Oil Extraction Level and Press Cake Appearance

The appearance of rice bran ‘cake’ or discharge from a screw press corresponds to the level of oil produced in the extraction process. The relationships between operating settings, oil extraction level and cake appearance were studied. Cake characteristics reliably indicate the expected oil recovery extraction level. These conclusions applyed to both Chainat 1 rice bran and parboiled rice bran. Variables were the speed of the screw press (set at five levels from 8.5 to 19.8 r/min) and corresponding clearance distances between the screw and barrel (set between 1.0 and 1.9 cm). Results showed that the maximum levels of extraction were 4.17% for the rice bran and 8.20% for the parboiled rice bran. At the maximum extraction level, the apparatus continuously discharged cake that were hard, crispy, flaky, shiny and polished on one side but dull and coarse on the other.