Showing papers on "Rice bran oil published in 2022"

Encapsulated oil powder: Processing, properties, and applications

Abstract: This review aimed to evaluate the applicability of microencapsulation of different oils (such as fish oil, sunflower oil, soyabean oil, palm oil, flaxseed oil, sesame oil, virgin coconut oil, and rice bran oil) by freeze drying, coacervation, fluidized bed coating, extrusion, and spray drying. Microencapsulation is the process of creating a functional barrier between the core and the wall material to avoid chemical and physical reactions and maintain the biological, functional, and physicochemical characteristics of the core material. The use of microencapsulated oils (oil powder) in food products provide a significant application in enhancing their functionalities due to the functional benefits of oils. However, utilization of simply oil leads to oxidation and other reactions causing deterioration of finished products quality. Microencapsulated oil has good oxidative stability, thermostability, shelf-life, and biological activity. Also, microencapsulation helps control the volatility and release properties of essential oils. This review focuses on the role of microencapsulation in increasing the stability, functional properties, and benefits of oils in various food products. Practical Application The comprehensive review on oil powder will be very useful for developing convenient and easily usable oil powder. The oil powder developed will have longer self-life, stability, and better health benefits. Oil powder can be used as a fortification in meat, dairy, and bakery products to enhance the nutritional value, fatty acids intakes, mouth feel, and textural properties. Such work will help the academic field as well as the industries to develop food products.

Integrated rice bran processing by supercritical CO2 extraction and subcritical water hydrolysis to obtain oil, fermentable sugars, and platform chemicals

Abstract: Rice bran is rich in oil and constituted by a lignocellulosic structure, which is a potential raw material for its processing into several products. Therefore, the oil yield and composition of oil obtained from supercritical CO2 extraction were investigated to select a condition for using defatted rice bran for processing by subcritical water hydrolysis. The effects of temperature (230 °C and 260 °C) and solvent-to-feed mass ratio (50 and 100 g water/g defatted rice bran) on fermentable sugar yield (YFS) and hydrolysate composition were evaluated and discussed. Supercritical CO2 extraction at 40 °C and 20 MPa provided an oil yield of 17.19 wt% at 120 min. For defatted rice bran, the highest YFS (6.53 g sugars/100 g defatted rice bran) was obtained at 260 °C and 100 g water/g defatted rice bran.

Microwave treatment of rice bran and its effect on phytochemical content and antioxidant activity

Abstract: An alternative approach for rice bran stabilization is microwave treatment. However, the effects of the microwave treatment on the contents of bioactive compounds and antioxidant activities of the rice bran have rarely been reported in detail. In this study, microwave pretreatment (130-880 W for 0.5-5.0 min) of rice bran was proposed where the antioxidant activity, total flavonoids, and total phenolic contents were determined using UV-Vis spectrometry. Tocols, γ-oryzanols, squalene, phytosterols and phenolic compounds were quantified using high-performance liquid chromatography. The results showed an increase in the antioxidant activity (0.5 folds), total phenolic contents (1.3 folds), total flavonoid contents (0.9 folds), total tocols (2.6 folds), total γ-oryzanols (1.6 folds), and total phytosterols (1.4 folds). Phytochemicals were enhanced, especially trans-p-coumaric acid (10.3 folds) and kaempferol (8.6 folds). The microwave treatment at 440 W for 2.5 min provided the best contents of the bioactive compounds and antioxidant activity. This work revealed the microwave treatment as a potential tool for stabilizing rice bran and increasing the usability of its phytochemicals, which applies to several industries concerning the use of rice bran as an ingredient.

Nanostructured lipid carrier for bioactive rice bran gamma-oryzanol

Abstract: The current work presents the development of a nanostructured lipid carrier (NLC) as a colloidal encapsulation and controlled release system for bioactive γ-oryzanol (GO) from rice bran oil. GO-loaded NLC (GO-NLC) were prepared using rice bran oil GO via a hot homogenisation method with sunflower oil (liquid lipid) and stearic acid (solid lipid) as the encapsulating lipid matrix, and rice bran phospholipids and Tween 80 as stabilisers. Fabricated GO-NLC had a 95% encapsulation efficiency with a spherical ‘yolk–shell’ morphology and a 143 nm mean particle diameter. A 60-day storage stability study showed that GO-NLC had high GO retention (>90%) at ambient temperature in light and dark conditions. In vitro release studies demonstrated that GO can be released from GO-NLC via different modes: slow controlled release into simulated intestinal fluid, following the Korsmeyer-Peppas model, and rapidly into a surfactant solution (Tween 80), following first-order release kinetics. Lastly, in vitro studies showed encapsulation of GO in NLCs afforded an 18-fold increase in free radical-scavenging activity, a two-fold increase in hyaluronidase-inhibitory, and a 200-fold improvement in anti-inflammatory activity. These suggest that GO-NLC is a suitable GO delivery system, which can either perform as an oral extended-release formulation or a rapid-release, surfactant triggered system, with improved health-promoting bioactivities.

Feasibility of Jatropha and Rice bran vegetable oils as sustainable EDM dielectrics

Abstract: ABSTRACT Electrical discharge machining (EDM) is a nontraditional machining process used for machining hard conductive materials by employing an electrically conductive tool and dielectric. In present days, biodielectric fluids are being used as substitutes with some exceptional attributes in EDM. In that context, the objective of the current work is to study the effectiveness of vegetable oil as dielectric fluid in EDM. In this article, experiment has been conducted using Jatropha biodiesel (Jatropha BD), Rice bran biodiesel (Rice bran BD) and EDM oil as dielectric fluid. The experimental results have reported that the material removal rate (MRR) patterns of Jatropha BD and Rice bran BD oil are almost similar to those of EDM oil, whereas in most of the cases, Jatropha BD displays better surface quality than the Rice bran BD oil. However, both the vegetable oils show superior surface quality compared to EDM oil. Evolvements of unhygienic and toxic gases and generation of nonbiodegradable wastes are few of the critical issues for inferior sustainability and biodegradability of dielectrics. Based on the test results of dissolved gas analysis, transesterified Jatropha oil and Rice Bran oil have been introduced as sustainable and biodegradable dielectrics in EDM.

Natural variation and underlying genetic loci of γ‐oryzanol in Asian cultivated rice seeds

Abstract: γ‐oryzanol is the most studied component in rice (Oryza sativa L.) bran oil. It is not only associated with physiological processes of rice growth and development but also grain quality that is related to human health. Previous studies focused mainly on γ‐oryzanol composition and content in various rice cultivars, while its biosynthetic and regulatory pathways remain unknown. Here we present the quantitative identification of γ‐oryzanol in rice seeds across 179 Asian cultivated accessions using ultra‐performance liquid chromatography–time‐of‐flight mass spectrometry (UPLC‐TOF/MS), which revealed a significant natural variation in γ‐oryzanol content among these tested rice accessions. In addition, we present, for the first time, the genome‐wide association study (GWAS) on rice seed γ‐oryzanol, which identified 187 GWAS signal hot spots and 13 candidate genes that are associated with variable γ‐oryzanol content and provided the top 10 rice haplotypes with high γ‐oryzanol content for breeding. Collectively, our study provides valuable germplasms for breeding rice cultivars rich in γ‐oryzanol and genetic resources for elucidating genetic and biochemical bases of variable γ‐oryzanol in rice.

Rice Bran Stabilisation and Oil Extraction Using the Microwave-Assisted Method and Its Effects on GABA and Gamma-Oryzanol Compounds

Abstract: Rice bran oil (RBO) is a valuable ingredient extracted from rice bran (RB), a side stream of polishing rice grain in the milling process. RBO is rich in bioactive ingredients with potential health benefits, such as gamma-oryzanol (GO) and gamma-aminobutyric acid (GABA). Despite its benefits, the quality of RBO depends on the degree of stabilisation of the RB, which is easily affected by lipase enzymes, and thus needs an effective treatment prior to RBO production. To assess the potential of the microwave-assisted method for RB stabilisation and RBO extraction, three Carolino rice varieties (Ariete, Teti, Luna) were tested. The effect of RB stabilisation was evaluated via acid value, water absorption, and GO and GABA levels. The RBO yield was optimised by solvent, temperature, and solvent-to-sample ratio, and the GO and fatty acid levels were determined. The RB stabilisation for the Luna variety did not affect the GO and GABA; for the Ariete and Teti varieties, the GO decreased by 34.4% and 24.2%, and the GABA increased by 26.5% and 47.0%, respectively. The GO levels in RBO samples were not affected by RB stabilisation. The RBO nutritional value was confirmed by the suitable ratio (>2) between polyunsaturated (PUFA) and saturated fatty acids (SFA), with the Teti variety presenting the highest ratio.

Production of rice bran oil (Oryza sativa L.) microparticles by spray drying taking advantage of the technological properties of cereal co-products

Abstract: Abstract Microparticles loaded with rice bran oil were produced by spray drying. Rice flour (RF) and rice protein (RP), considered as co-products of the cereal production chain, were tested as stabilizers in the encapsulation process to improve emulsion stability and the properties of the particles. Rice bran oil presented 1.75% ɣ-oryzanol, a powerful antioxidant with health benefits. AG/RP treatment (10% of rice protein): no phase separation after 24 h, higher zeta potential (-29.09 mV ± 0.67), encapsulation efficiency (73.90% ± 0.22), real density (1.27 g/cm−3), and smaller particle size (8.27 μm ± 0.13). Microparticles containing co-products were the most appropriate to slow down the autooxidation (at 60°C for 8 weeks), especially associated with the use of rice flour. The co-products improve the emulsion characteristics, particle properties and stability of the encapsulated oil. This study presented the technological effects of the use of rice chain co-products, which is in line with the current scenario of sustainability.

Effects of Extraction Processes on the Oxidative Stability, Bioactive Phytochemicals, and Antioxidant Activity of Crude Rice Bran Oil

Abstract: This research investigates the effects of different extraction processes on the oil extractability, oxidative stability, bioactive compounds, and antioxidant activity of crude rice bran oil (CRBO). The experimental extraction processes include hexane extraction (HE), cold press extraction (CE), thermally pretreated cold press extraction (CCE), and ultrasound-pretreated cold press extraction (UCE). The results show that thermal cooking and ultrasound pretreatment significantly improve the oil extractability of the cold press extraction process. The oil yields of CE, CCE, and UCE were 14.27, 17.31, and 16.68 g oil/100 g rice bran, respectively. The oxidative stability of CE and CCE oils was higher than HE and UCE oils, as evidenced by the synchrotron-radiation-based Fourier transform infrared (SR-FTIR) absorption peak. The ρ-anisidine values of HE, CE, CCE, and UCE were 0.30, 0.20, 0.91, and 0.31, respectively. Meanwhile, ultrasound pretreatment significantly reduced the bioactive compounds and chemical antioxidant activity of UCE oil. The CE, CCE, and UCE oils (0.1% oil concentration) exhibited higher inhibitory effects against hydrogen-peroxide-induced cellular oxidative stress, compared to HE oil (0.39% oil concentration). Essentially, CCE is operationally and environmentally suitable for improving the oil yield, oxidative stability, bioactive compounds, and antioxidant activities of CRBO.

Changes in physicochemical characteristics of rice bran oil during mechanical‐stirring and ultrasonic‐assisted enzymatic degumming

Abstract: The current study investigated the comparison of enzymatic (phospholipase A1) degumming of crude rice bran oil on the mechanical-stirring and ultrasonic-assisted systems. The effect of process parameters like, water (1.5%, 2%, 2.5%, 3%, and 3.5%) and enzyme dosage (1.2, 1.8, 2.4, 3, and 3.6 ml/kg) and temperature (35, 40, 45, 50, and 55°C) was studied for mechanical-stirring enzymatic degumming process. The maximum removal of phospholipids by mechanical-stirring enzymatic degumming was observed with 3% water and 3.6 ml/kg of the enzyme at 40°C. Using the optimized levels of water, enzyme, and temperature, enzymatic degumming was carried out under ultrasonication with different power levels (20%, 30%, 40%, and 50%). The ultrasonic power level of 325 W (50% amplitude) showed maximum phospholipid removal with lesser time. Compared to mechanical-stirring enzymatic degumming, ultrasonic-assisted enzymatic degumming had a higher cavitational yield, leading to enhanced enzyme activity and maximum phospholipids removal. The studies on the physicochemical properties showed that ultrasonic-assisted enzymatic degumming induced hydrolytic rancidity and primary oil oxidation due to the cavitation effect. As a result, more emphasis should be paid to the oxidative stability of the oil in future applications. Practical Applications Degumming is the preliminary and important step in the refining of oil. Chemical degumming approaches don't remove maximum phospholipids and also cause higher neutralized oil loss. Enzymatic degumming results in maximum removal of phospholipids from the oil but also takes a long time to reduce the phosphorus content below the desired level. The application of ultrasound on enzymatic degumming effectively increases the reaction rate in lesser time. The ultrasonic-assisted enzymatic degumming also results in better oil quality and physio-chemical parameters. So, ultrasound can be effectively applied to enzymatic degumming of rice bran oil.

Extraction of Rice Bran Oil Using CO2-Expanded Hexane in the Two-Phase Region

Abstract: The performance of CO2-expanded hexane in the vapor-liquid two-phase region was examined to extract phosphorus-free bio-oil from rice bran. Previously, it was found that in the uniform liquid phase region, it is difficult to maintain the phosphorus concentration at a stable and low level when the CO2 mole fraction changed slightly. To overcome this issue, the dependences of the phosphorus and free fatty acid concentrations, the oil solubility, and the oil yield on the CO2 mole fraction in the CO2-expanded hexane were measured at 25 °C, 5.1–5.2 MPa, and at a CO2 mole fraction of 0.88–0.94 in the two-phase region. Thus, a relatively constant phosphorus concentration of <10 ppm was maintained in the extracted oil, which was ~1/50 of that in the oil extracted by hexane, thereby satisfying the European unified standard for biodiesel fuel. Furthermore, a high oil yield exceeding that of hexane extraction was maintained over all CO2 mole fractions. Moreover, the oil solubility in the CO2-expanded hexane decreased linearly with the CO2 mole fraction, and so this factor represented the oil-dissolving power of the extractant more accurately than the oil yield used previously. The free fatty acid concentration was 83% of that extracted by hexane.

Metabolic aspects of oryzanol in rats

Abstract: Using a rat model, this study compared the bioavailability of three forms of oryzanol, a compound extracted from rice bran oil that has been associated with improved cholesterol levels. Various methods of extracting lipids from serum and liver were explored to determine oryzanol absorption. Cholesterol levels were obtained via enzymatic colorimetric assay and GCMS. Sprague Dawley retired female breeder rats were sustained for 11 weeks on a cholesterol-free diet to which either no oryzanol was added (n = 19) or 2.8 g/kg of oryzanol was added as: 7% oryzanol rice bran oil (RO, n = 8), crystalline oryzanol (CO, n = 8), or crystalline oryzanol dissolved in tocopherol-stripped corn oil (DO, n = 9). The percentage of dietary oryzanol recovered in the feces of rats fed the CO diet (41.9 ± 2.21, mean ± SEM) was significantly higher compared to the RO (28.3 ± 3.54) and DO (27.8 ± 2.63) groups (P < 0.05), suggesting that bioavailability of crystalline oryzanol is lower relative to the oil forms. Oryzanol was not detected during GCMS analysis of serum following hexane extraction. Similarly, hexane extractions of liver analyzed via HPLC and GCMS did not reveal oryzanol. Hexane may not be an appropriate solvent for extracting oryzanol, or perhaps the compound is metabolized prior to its entry into the liver or bloodstream. Although serum cholesterol levels determined by colorimetric enzymatic assay did not differ significantly among the groups, levels were highest in the RO group, followed in sequence by the DO, CO, and oryzanol-free controls. It is likely that a cholesterol-enriched diet is required for the hypolipidemic effect of oryzanol to be realized. Additionally, it is plausible that the cholesterol values from the oryzanol-fed animals were inflated by phytosterols in the serum. Hexane extractions of serum analyzed via GCMS resulted in unintelligible data, suggesting that hexane is not a suitable solvent for the extraction of cholesterol from serum. Although a 2:1 chloroform:methanol mixture (Folch et al., 1956) resulted in more uniform values, it appeared that the extraction of total cholesterol from lipoproteins was incomplete. (Supported by USDA IFAFS 2000-04222)

Optimization of Oil Extraction from Rice Bran with Mixed Solvent Using Response Surface Methodology

Abstract: In order to improve the extraction ratio of rice bran oil, a single-factor experiment and response surface methodology with a central composite design were used to determine a new mixed solvent and the optimal extraction conditions of the mixed solvent. The effects of solid–liquid ratio, extraction time, extraction temperature, and oscillation speed on the extraction ratio were investigated. The regression equation was established, and the optimal extraction conditions were determined as follows: a solid–liquid ratio of 5.5:1, extraction temperature of 45 °C, extraction time of 12 min, and extraction ratio of rice bran oil of 85.8%. Compared with traditional solvent extraction, the peroxide value, acid value, iodine value, and fatty acid composition content of rice bran oil extracted using the new mixed solvent were close to those of n-hexane and significantly lower than those of solvent No. 6, while the content of oryzanol and total sterol increased to 2.7% and 5.1%. This study can be useful in exploring the possibility of new mixed solvents and provide theoretical guidance and data support for the production practice of new mixed solvents.