Quantitative analysis of γ-oryzanol content in cold pressed rice bran oil by TLC-image analysis method

Objective:To develop and validate an image analysis method for quantitative analysis ofγ-oryzanol in cold pressed rice bran oil.Methods:TLC-densitometric and TLC-image analysis methods were developed,validated,and used for quantitative analysis of γ-oryzanol in cold pressed rice bran oil.The results obtained by these two different quantification methods were compared by paired t-test.Results:Both assays provided good linearity,accuracy,reproducibility and selectivity for determination of γ-oryzanol.Conclusions:The TLC-densitomelric and TLC-image analysis methods providett a similar reproducibility,accuracy and selectivity for the quantitative determination of γ-oryzanol in cold pressed rice bran oil.A statistical comparison of the quantitative determinations of γ-oryzanol in samples did not show any statistically significant difference between TLC-densitometric and TLC-image analysis methods.As both methods were found to be equal,they therefore can be used for the determination of γ-oryzanol in cold pressed rice bran oil.

Enzymatic Synthesis of Fatty Acid Methyl Esters from Crude Rice Bran Oil with Immobilized Candida sp. 99-125

The non-edible crude rice bran oil was extracted from white rice bran, and then was catalyzed by immobilized lipase for biodiesel production in this study. The effects of water content, oil/methanol molar ratio, temperature, enzyme amount, solvent,number of methanol added times and two-step methanolysis by using Candida sp. 99-125 as catalyst were investigated. The optimal conditions for processing 1 g rice bran oil were: 0.2 g immobilized lipase, 2 ml n-hexane as solvent, 20% water based on the rice bran oil mass, temperature of 40 °C and two-step addition of methanol. As a result, the fatty acid methyl esters yield was 87.4%. The immobilized lipase was proved to be stable when it was used repeatedly for 7 cycles.

Rice Bran Oil: Emerging Trends in Extraction, Health Benefit, and Its Industrial Application

Rice bran oil(RBO)is unique among edible vegetable oils because of its unique fatty acid composition,phenolic compound(γ-oryzanol,ferulic acid)and vitamin E(tocopherol and tocotrienol).It has become a great choice of cooking oil because of its very high burning point,neutral taste and delicate flavour.Non-conventional methods of RBO extraction are more efficient and environmentally friendly than conventional extraction methods.Advances in RBO extraction using innovative extraction strategies like super/sub-critical CO_(2),microwave-assisted,subcritical H_(2)O,enzyme-assisted aqueous and ultrasoundassisted aqueous extraction methods have proven to significantly improve the yields along with improved nutritional profile of RBO.The compositions and strategies for stabilization of RBO are well discussed.The constituents are present in the RBO contribute to antioxidative,anti-inflammatory,antimicrobial,antidiabetic and anti-cancerous properties to RBO.This has helped RBO to become an important substrate for the application in food(cooking oil,milk product and meat product)and non-food industries(polymer,lubricant,biofuel,structural lipid and cosmetic).This review provided comprehensive information on RBO extraction methods,oil stabilization,existing applications and health benefits.

Optimization of Extraction Technology for Rice Bran Oil

[ Objective ] This study aimed to optimize the extraction technology for rice bran oil. [ Method ] Using rice bran as raw material, effects of ultrasonicassisted extraction technology and different organic solvents, extraction durations, solid-liquid ratios and extraction temperatures on extraction results of rice bran oil were investigated. Based on the results of single-factor experiment, L9 （34 ） orthngonal experiment with three factors at three levels was conducted to optimize the extraction technological parameters, thus obtaining the optimal technological conditions for extracting rice bran oil. [ Result] Anhydrous ethanol led to the best extraction result; after ultrasonic treatment, the extraction rate of rice bran oil from raw material was not enhanced. The optimized technological parameters were ： extraction temperature of 80 ℃, extraction duration of 20 rain and solid-liquid ratio of 1：24 （ g： ml）. Under the optimized technological conditions, the extraction rate of rice bran oil reached 19.33%. [ Conclusion] This study laid solid foundation for further investigation and development of rice bran oil.

Laboratory studies of rice bran as a carbon source to stimulate indigenous microorganisms in oil reservoirs

There is a great interest in developing cost-efficient nutrients to stimulate microorganisms in indigenous microbial enhanced oil recovery（IMEOR） processes.In the present study,the potential of rice bran as a carbon source for promoting IMEOR was investigated on a laboratory scale.The co-applications of rice bran,K2HPO4 and urea under optimized bio-stimulation conditions significantly increased the production of gases,acids and emulsifiers.The structure and diversity of microbial community greatly changed during the IMEOR process,in which Clostridium sp.,Acidobacteria sp.,Bacillus sp.,and Pseudomonas sp.were dominant.Pressurization,acidification and emulsification due to microbial activities and interactions markedly improved the IMEOR processes.This study indicated that rice bran is a potential carbon source for IMEOR.

Effect of Blended Rice Bran and Olive Oil on Cardiovascular Risk Factors in Hyperlipidemic Patients

The present study was designed to evaluate the effectiveness of blended rice bran and olive oil on hyperlipidemic subjects. A total of 60 moderately hyperlipidemic patients (Total Cholesterol (TC) >200 mg/dl and/or Triglycerides (TG) >150 mg/dl) with an age range of 45 - 60 were selected from Mediciti Hospital of Ludhiana and were divided into two groups: Group A and Group B containing 30 subjects each. The subjects of Group B were given blended rice bran and olive oil for a time period of 45 days and were asked to continue with their routine eating and physical activity pattern. The subjects of Group A were kept on their regular cooking oil. The serum lipid values were assessed before and after the study. Additional parameters assessed included anthropometry, dietary fat intake and physical activity pattern. The results showed that there was an insignificant change in the average body mass index (BMI) of the subjects of Group B before (27.0 kg/m2) and after (26.9 kg/m2) the study respectively. Also, there was an insignificant change in the lipid levels of the subjects of Group B after the study. The levels of TC and LDL cholesterol decreased by 3.7 and 9.0 percent respectively. Whereas, the levels of TG and VLDL cholesterol increased by 9.5 percent in the subjects of Group B after the feeding trials. Further, systolic and diastolic blood pressure of the subjects of Group B reduced by 2.9 and 2.3 percent respectively. An insignificant change was observed in all the parameters of selected subjects. So, the present study recommends carrying out more long duration research studies to evaluate the effectiveness of this blended oil.

Pilot Scale Mill Characterization and Evaluation of Rice Bran Oil Concentration of Jazzman Rice

The demand for aromatic rice has increased in the United States during the last two decades. Jazzman, the first US-bred jasmine-type rice variety, was released by the Louisiana State University (LSU) AgCenter Rice Research Station in 2008 to compete for a market share of jasmine-type rice. Jazzman, a long grain aromatic rice variety, was developed from a cross between Ahrent and an unreleased aromatic Chinese rice line 96a-8. In pre-release field tests and laboratory scale evaluation, Jazzman rice yield and milling quality compared favorably with two high-yielding and good-milling non-aromatic long grain varieties, Cypress and Cheniere. Pilot scale evaluation of Jazzman for milling quality supported laboratory scale evaluation while providing additional data for milling optimization. Pilot scale milling uses larger rice samples than laboratory scale testing and employs a continuous process instead of the batch process used at laboratory scale. As a result, pilot scale milling offers more comprehensive information regarding the milling yield and quality of rice varieties as they are considered for industrial scale release. Another consideration for new rice varieties involves their potential for value-added processing, in which waste streams during processing can be used to create valuable products. The oil from rice bran is one such product. The objective of this study was to use pilot scale milling to determine the potential of Jazzman for industrial scale release, including its potential for value-added processing. Results showed that bran was easily removed during milling;the head rice recovery ranged from 66% to 74% as a function of milling flow rate. Water polishing had little effect on head rice recovery, but improved the final degree of milling (DOM) to a commercially acceptable level of 87 - 90. Additionally, rice bran oil concentration decreased as pilot scale flow rate increased, indicating that oil was concentrated in the outer bran layer of Jazzman. Pilot scale milling shows that Jazzman is a high-yielding and good-milling aromatic long grain rice variety.

Effects of Tocols Rich Fraction Isolated from Rice Bran Oil Deodorizer Distillate on Plasma and Hepatic Lipid Concentrations in Rats

A great deal of attention has been focused on the potential health benefits of using rice bran oil because it is a rich source of bioactive compounds. Rice bran oil deodorizer distillate (RBODD) is a byproduct obtained from distillation of rice bran oil. Elevated plasma cholesterol level is one of the major risk factors for coronary heart disease. The objective of this study was to investigate the effects of tocols (tocopherols + tocotrienols) rich fraction isolated from RBODD on plasma and liver lipid concentrations in rats. Male Sprague Dawley rats (6 weeks of age) were randomly assigned into three groups: normal fat control (NFC), high fat control (HFC) and high fat diet plus tocols rich fraction (RBODD). RBODD was administered daily for 3 weeks by oral gavage using 5% of Tween-80 as a vehicle. The rats in the control groups received 5% of Tween-80 alone in the same manner. Blood samples and livers were collected at the end of the feeding period. RBODD group had significantly lower plasma triglyceride levels compared to the HFC group (p < 0.05). However, no significant changes for plasma total and lipoprotein cholesterol levels were found in RBODD compared with HFC. Compared to the rat fed HFC, hepatic free fatty acids were significantly reduced in the rats with the RBODD treatment (p < 0.05). The results suggest that the tocols rich fraction isolated from RBODD is associated with decreased plasma triglyceride and hepatic free fatty acids concentrations. Further study is needed to investigate the mechanism and optimal dose by which isomers of tocols lower triglyceride concentrations.

Application of Taguchi’s Orthogonal Array in Multi Response Optimization of NO_xEmission of Crude Rice Bran Oil Methyl Ester Blend as a CI Engine Fuel

In this work an attempt was made to minimize the NOx emission of a crude rice bran oil methyl ester (CRBME) blend with less sacrifice on smoke density and brake thermal efficiency. Three factors namely fuel injection timing, percentage EGR and fuel injection pressure were chosen as the influencing factors for the set objective. Experiments were designed by employing design of experiments method and Taguchi’s L9 orthogonal array was used to test the engine. MRSN ratio was calculated for the response variables and the optimum combination level of factors was obtained simultaneously using Taguchi’s parametric design. ANOVA was employed to analyze the variance of MRSN and the most influencing factor for the set objective was taken from the ANOVA table. Obtained combination was confirmed experimentally and significant improvement was observed in the response variables.

Production of Rice Bran Oil in India: a Technical Evaluation

India has the highest utilization of rice bran oil in terms of the available resources in the country.Parboiled rice tradition has made the available rice bran in relatively good quality.This makes the quality of crude rice bran oil being also high.Therefore the following processing is made relatively simple comparing with those high free fatty acid content crude rice bran oils.In India,physical refining is commonly used.Thus the oil refining yield is usually high.The unsaponifiable content is also higher comparatively.For example,oryzanol content is usually 1%to 1.5%in weight.Although there are a large number of rice bran oil small plants in India,the technology is relatively mature for the production of relatively good quality rice bran oil.In this short overview of the production technology of rice bran oil in India,the state of the art has been elaborated in a simple form.Particularly,the problems and challenges of the production technology have been evaluated with the background of decades of research and technology development work in India.

Nutrition and Applications of Rice Bran Oil: a Mini-overview

Rice bran oil is a healthy oil from many aspects.The oil has a balanced fatty acid profile comparing with many other vegetable oils.The key difference is the minor components or micronutrients or unsaponifiable matters contained in the oil that are very special and in larger percentages.The oil contains more than 1.5%oryzanol that gives nutritional and pharmaceutical functions from the studies so far.More studies are needed to demonstrate the wide functions in many aspects.The oil also contains large percentage of phytosterols which received huge amount of studies for nutritional applications.Furthermore,the oil contains tocopherols and tocotrienols,in which for the later particularly it gives many special functions including prevention of breast cancers for example.When the oil is properly processed and used in foods,those functions are more and more demonstrated in nutritional or biological studies.Thus the oil in food and pharmaceutical applications is in exploring both in academic studies and industrial practice.In this work,an overview of such progress is given.

Oxidative Stability of Green Tea Extract-Enriched Rice Bran Oil During Storage

Adding green tea extract to rice bran oil was expected to improve its oxidative stability,so this study was conducted to investigate oxidative stability of green tea extract-enriched rice bran oil(RBOG) during storage at 60℃ for 15 days compared to rice bran oil(RBO),olive(OL),canola(CN),and grape-seed oil(GS).Acid values did not increase during storage,and the highest value was found for OL.The peroxide values of RBOG,RBO,CN,OL,and GS increased for up to 15 days.The highest average rate constant for the change in peroxide value was found for RBO(0.282).TBARS increased continually during storage of RBOG,RBO,CN,and OL;however,the value increased for up to 9 days and then decreased for GS.The highest average rate constant of change in TBARS was found for CN.Overall,the results suggest that green tea extract improves oxidative stability of rice bran oil.

Liquefied dimethyl ether as alternative extraction solvent for high 𝛾γ-oryzanol rice bran oil: Systematic HSP theory and experimental evaluation

This study aimed to systematically find an alternative solvent to replace hexane for the extraction of bio-oil with high𝛾-oryzanol content from rice bran(RB).The selection involved predicting solubility through Hansen solubility theory,experimental validation,determination of suitable extraction conditions,and comparison of oil quality with that of conventional hexane.A wide variety of solvents:subcritical water(SCW),supercritical carbon dioxide(SCCO_(2)),bio-based sol-vents(alcohols and terpenes),and liquefied dimethyl ether(LDME),were initially assessed for rice bran oil(RBO)and𝛾-oryzanol solubility using Hansen solubility spheres.Solvents demon-strating high solubility for both RBO and𝛾-oryzanol,including LDME,ethyl acetate,acetone,and others(alcohols and SCCO_(2))known for effective vegetable oil extraction,were selected/identified for experimental extraction comparison.Among these,LDME performed better overall,affording greater solubility and requiring less solvent,shorter duration,lower pressure,and no additional co-solvents for equivalent extractions.Optimal conditions for LDME extraction were identified as 30℃ with a solvent-to-sample ratio of 10 mL/g and an extraction time of 10 min.Oils extracted with LDME and hexane displayed similar fatty acid compositions and no adverse effects on RB protein and carbohydrate structures after LDME extraction were observed.This study demon-strates LDME as a promising alternative to replace hexane for RBO extraction to further valorize this abundant low-cost RB residue into bio-oil and its𝛾γ-oryzanol and de-oil RB co-products.

A comprehensive review on anti-diabetic property of rice bran

Rice bran(RB) is one of the nutrient-rich agricultural byproducts. It is a composite of carbohydrates, lipids, proteins, fibers, minerals, and trace elements such as phosphorus, potassium, magnesium, calcium and manganese. The extraction and purification process influences the quality and quantity of rice bran oil, which is rich in tocopherols, tocotrienols, 毭-oryzanol, and unsaturated fatty acids. The bioactive components of RB have been reported for exhibiting antioxidant, anti-inflammatory, hypocholesterolemic, anti-cancer, anti-colitis, and antidiabetic properties. In vitro and in vivo studies, and clinical trials in human volunteers revealed the anti-hyperglycemic activity of RB derived compounds. An updated comprehensive review on the antidiabetic property of RB and its derivative is required to appraise the current knowledge in the particular field. Thus, the present paper covered the composition and bioactivities of RB, and influence of extraction methods on the biological property of rice bran oil and rice bran extract. And the current review also focused on the reported antihyperglycemia activity of rice bran derivatives, and its probable mechanism.

米糠油加工过程中组成及品质变化的研究

旨在为米糠油适度加工提供数据支撑,对来自国内3个工厂的不同加工阶段米糠油的理化指标、组成、色泽和微量成分进行了测定。结果表明:A、B、C 3个工厂的米糠油在精炼后酸值(KOH)分别由24.22、18.95、17.21 mg/g降至0.15 mg/g以下,脂肪酸脱除率高达99%以上,过氧化值分别降至0.99、1.54、0.71 mmol/kg,精炼后米糠油酸值、过氧化值均达到GB/T 19112-2003中一级油标准;3个工厂的米糠油在加工过程中其游离脂肪酸含量变化趋势与酸值的变化趋势一致;精炼后米糠油甘一酯含量降低了58.9%~84.9%,主要在物理脱酸和脱臭时脱除,甘二酯含量变化不大,甘三酯含量增加了12.8%~23.9%;3个工厂米糠油脂肪酸组成在加工过程中没有明显变化;精炼后米糠油中叶绿素被有效脱除,色泽均达到国标一级油标准;米糠油的微量成分在加工过程中变化极大,其中谷维素出现明显的损失,损失率高达80.8%~94.1%,主要在化学脱酸时损失,甾醇损失率为21.2%~42.6%,主要在化学脱酸时损失,维生素E含量变化趋势存在差异,A工厂维生素E含量增加30.2%,B、C工厂维生素E损失率分别为31.7%、55.6%;角鲨烯损失率为65.9%~96.3%,主要发生在脱臭工序。综上,企业应根据自己的定位,合理调整精炼工序,优化精炼工艺参数,生产出符合企业追求的米糠油产品。

Lipozyme TL100L催化米糠酸化油制备生物柴油的工艺研究

旨在为米糠酸化油的产业化应用提供参考,以米糠酸化油为原料,经丙酮提取预处理后,采用酶法催化制备生物柴油。通过单因素实验考察脂肪酶种类、酶添加量、醇油物质的量比和反应温度对生物柴油产率的影响,结合正交实验对生物柴油制备的工艺条件进行优化,并采用分子蒸馏对生物柴油进行精制,同时对精制生物柴油进行表征。结果表明:米糠酸化油经预处理后,过氧化值、谷维素及不皂化物含量无显著变化,酸值、皂化值显著升高,水分及挥发物含量、磷脂含量、灰分和皂含量显著降低;生物柴油制备的最优工艺条件为醇油物质的量比3∶1、液体脂肪酶LipozymeTL100L添加量4%、反应温度30℃、反应时间4h,在此条件下生物柴油产率达(86.77±0.54)%,经分子蒸馏纯化后脂肪酸甲酯含量达(97.00±0.04)%;精制生物柴油理化指标均符合GB25199—2017要求;傅里叶红外光谱分析证实了产物中含脂肪酸甲酯,热重分析表明精制生物柴油在178.0~293.2℃区间内失重最快,差示扫描量热分析表明-37.5~-47.2℃的峰与不饱和脂肪酸甲酯的晶体有关,-7.9~-3.7℃的峰与饱和脂肪酸甲酯的晶体相关,生物柴油的结晶起始温度为-8.87℃。综上,以米糠酸化油为原料采用酶法制备生物柴油具有极大的发展潜力。

米糠油中呈色物质的分离和鉴定

米糠油的色泽是影响其品质的因素之一。该研究对米糠油中呈色物质的提取方法进行优化,并利用高效液相色谱串联质谱法对呈色物质进行分离和鉴定。以甲醇∶水(8∶2,体积比)为萃取剂,用液液萃取法提取米糠油中的强极性呈色物质,然后将样品皂化后利用正己烷提取弱极性呈色物质。强极性和弱极性提取液经质谱分别鉴定出9类物质,共37种,其中强极性提取液中二氢异黄酮类含量最多,弱极性提取液中二氢黄酮醇类为主要化合物。

负载叶黄素米糠油体乳液的制备及理化稳定性分析

叶黄素因其优异的生物活性被广泛关注,但水溶性差、易降解等缺点限制了其在食品加工中的应用。为解决以上问题,该研究以副产物米糠为原料,提取米糠油体作乳化剂,负载叶黄素的稻米油为油相,制备米糠油体叶黄素乳液,对乳液的物理稳定性、包封效果、流变特性、微观结构进行表征,探究乳液组分间相互作用以及乳液的储藏稳定性。研究结果表明,乳液的理化稳定性随着体系中油相浓度的增大而减小,当油相体积分数为10%时,乳液粒径为(481.03±34.39)nm,zeta电位值为(-38.07±0.46)mV;叶黄素与米糠油体主要通过氢键结合;在经过22 d的加速氧化后乳液中叶黄素的保留率接近65%。该研究结果可为开发植物油体递送载体提供理论与技术基础。

稻米油及其γ-谷维素营养的研究进展

我国稻米资源丰富,其加工产物稻米油(RBO)不仅脂肪酸组成均衡,还富含γ-谷维素、植物甾醇、维生素E等脂质伴随物,对人体健康十分有益。对稻米油及其γ-谷维素营养研究进展进行检索分析,阐述了稻米油及其γ-谷维素在血脂、血糖、情绪/睡眠、肌肉力量/运动表现、免疫调节等方面的营养功效及潜在机制,其中关于RBO对血脂影响的临床研究最多,食用RBO可能有效改善成人受试者的脂质参数,降低血脂异常/高脂血症风险,以预防和控制心血管疾病。为整体了解稻米油及γ-谷维素营养特性及潜在应用价值,未来需进一步探索RBO在不同人群中健康效应及作用机制。

热处理条件下米糠油中谷维素的损失规律研究

旨在为米糠油的精准适度加工及其在食品工业中的应用提供科学指导,研究了常压和充氮加热(60~260℃)处理0~12 h条件下米糠油中谷维素及其4种主要组分[环木菠萝烯醇阿魏酸酯(CAFA)、24-亚甲基环木菠萝烯醇阿魏酸酯(24-MCAFA)、菜油甾醇阿魏酸酯(CampFA)及β-谷甾醇阿魏酸酯(SitoFA)]的损失规律。结果表明:两种加热方式下谷维素及其4种主要组分的损失率随加热时间的延长均呈线性上升趋势(R^(2)>0.90),损失速率随着加热温度升高而升高;在常压加热条件下,当温度达到220℃时谷维素开始快速损失,260℃下加热12 h时谷维素总量损失率最高(74.14%);谷维素4种主要组分在两种热处理过程中热稳定性相似,即不高于140℃时各组分之间热稳定性总体无显著差异,不低于180℃时各组分热稳定性大小顺序为CampFA>CAFA>24-MCAFA>SitoFA;充氮加热下谷维素损失率变化趋势与常压加热下相似,但其损失率显著低于常压加热(除140℃和60℃),在220℃下加热12 h时两者相差最大(32.34百分点)。综上,米糠油应采用适度加工工艺及在食品工业应用中应合理控制加热条件以减少谷维素的损失,提高米糠油的营养品质。