Hydrogenation of Low Erucic Acid Rapeseed Oil

The effects of some process conditions on the overall reaction rate and on trans isomer formation during hydrogenation of low erucic acid rapeseed oil with a commercial nickel catalyst were studied. Experimental data were correlated by an empirical equation which would be used to predict the reaction rate constants for any given process conditions. Temperature had a major effect on rate and trans isomer formation. Pressure and catalyst concentration, however, had only minor effects. It is suggested that apart from these factors, the extent of trans isomer formed is also controlled by the nature and amount of the unsaturation in the oil and by the overall reaction rate. A new parameter, specific isomerization index was introduced to represent the formation of trans isomers during the hydrogenation reaction. The effects of solvents n-hexane and 2-propanol on the reaction rate and trans isomers formation were determined.     

Effect of Erucic Acid on the Polymorphism of Hydrogenated Rapeseed Oil

The polymorphism of rapeseed oils with high and low erucic acid content was investigated using differential scanning calorimetry and X-ray diffraction. Both oils were hydrogenated to various iodine values. The fatty acid pattern showed that erucic acid is slowly saturated. The melting curves were followed by DSC and pulsed NMR. For low iodine value the low erucic acid rapeseed oil exhibits a second melting peak owing to the appearance of new triglycerides with different properties. Samples of hydrogenated rapeseed oils were aged at 20°C and 29°C. The short spacings determinations indicate that the β' → β transition is faster for the low erucic acid rapeseed oil (LEAR) than for the high erucic acid rapeseed oil (HEAR).     

Hydrogenation Characteristics of High Erucic Rapeseed Oil

Twenty-seven experiments were done to study the hydrogenation characteristics of high erucic rapeseed oil, with the experiments being designed systematically according to orthogonal test. The characteristics include the influence of operating variables on the reaction rate (average reaction rate and instantaneous reaction rate) and on the relationship between melting point and iodine value of the finished product, and the induction time of reactions under different conditions. Reaction rate and melting point models were generated from the experimental data. The results show that temperature has the most significant effect on the reaction rate, followed by catalyst concentration and hydrogen pressure. The correlation between melting point and iodine value of the hydrogenated product was greatly affected by the operating variables, especially temperature. Melting point will decrease as temperature increases at a given iodine value. Induction time is relatively long at temperature below 170°C.     

Effect of Dehulling Treatment on the Oxidative Stability of Cold-Pressed Low Erucic Acid Rapeseed Oil

This study compared the oxidative stability of cold-pressed rapeseed oil (CPRO) and dehulled cold-pressed rapeseed oil (DCPRO) in the dark at 60 °C and monitored the evolution of minor constituents (tocopherols, phytosterols, phenolics). The results showed that dehulling significantly influenced the oxidative stability of the oils, the DCPRO was more easily oxidized. During the autoxidation, the peroxide value (PV) and anisidine value (p-AV) of the DCPRO ranged from 2.38 to 95.97 mequiv O₂ kg⁻¹ and from 1.20 to 30.75, whereas those of the CPRO ranged from 3.80 to 46.17 mequiv O₂ kg⁻¹and from 2.69 to 14.87, respectively. Dehulling affected the contents and the rates of decrease of tocopherols and phytosterols of the cold-pressed oils, and the rates of decrease of tocopherols and phytosterols of the CPRO were lower than those of the DCPRO (10% less, on average). The rancimat induction periods (IPs) were positively correlated with the concentrations of the total tocopherols (For DCPRO, R ² = 0.9622, For CPRO, R ² = 0.8334). The total phenolics contents as determined by spectrophotometry first increased and then decreased. Tocopherols and phytosterols had a greater effect on oxidative stability of the rapeseed oils during the first 30 days, and phenolics had a greater effect in the 30–40 day period.     

Recovery of Oil,Erucic Acid,and Phenolic Compounds from Rapeseed and Rocket Seeds

Erucic acid‐enriched oil, sought for industrial purposes, from rapeseed (agronomic plant) and rocket seeds (non‐agronomic plant) was extracted by three different processes: supercritical CO₂, mechanical expression, and hexane extraction. Oil extraction yields were determined and the extracted oils were characterized for their fatty acid and phenolic compound compositions. Higher oil yields were achieved using hexane compared to mechanical expression and supercritical CO₂ extractions. Fatty acid analysis indicated a higher content of erucic acid in rapeseed oil than in rocket oil. In addition, supercritical CO₂ extraction allowed better recovery of phenolic compounds with high antioxidant activities. The most prominent identified polyphenols were vanillin, sinapic acid, syringic acid, and apigenin.     

The Preparation of Rapeseed Lecithin with High Phosphatidylcholine Content

The raw commercial rapeseed lecithin free of erucic acid and glucosinolate (00-type) was purified by deoiling with acetone and extracting with ethanol. The increasing of phosphatidylcholine (PC) content (from 50 to 70–80%) in obtained rapeseed lecithin extract was performed. It was done by column chromatographic fractionation using a low silica gel–lecithin extract ratio about 2:1 and the various temperatures up to 60°C. The fractions were eluted with 95% ethanol. Effect of rapeseed lecithin column fractionation temperatures is significant and the better purification quality in the higher temperatures was observed. Based on performed investigations it could be summarized that the low silica gel–lecithin extract ratio (2:1) allows to obtain rapeseed lecithin with above 80% content of PC and the best results for temperature 60°C were observed.     

High Serum Palmitic Acid is Associated with Low Antiviral Effects of Interferon-Based Therapy for Hepatitis C Virus

Hepatitis C virus (HCV) infection alters fatty acid synthesis and metabolism in association with HCV replication. The present study examined the effect of serum fatty acid composition on interferon (IFN)-based therapy. Fifty-five patients with HCV were enrolled and received IFN-based therapy. Patient characteristics, laboratory data (including fatty acids), and viral factors that could be associated with the anti-HCV effects of IFN-based therapy were evaluated. The effects of individual fatty acids on viral replication and IFN-based therapy were also examined in an in-vitro system. Multivariate logistic regression analysis showed that the level of serum palmitic acid before treatment and HCV genotype were significant predictors for rapid virological response (RVR), early virological response (EVR), and sustained virological response (SVR). High levels of palmitic acid inhibited the anti-HCV effects of IFN-based therapy. HCV replication assays confirmed the inhibitory effects of palmitic acid on anti-HCV therapy. The concentration of serum palmitic acid is an independent predictive factor for RVR, EVR, and SVR in IFN-based antiviral therapy. These results suggest that the effect of IFN-based antiviral therapy in patients with HCV infection might be enhanced by treatment that modulates palmitic acid levels.     

使用含夹带剂的超临界CO2分离菜籽油中的芥酸

Separation of erucic acid from rape-seed oil using supercritical carbon dioxide with entrainer was carried on a pilot column with an inner diameter 14 mm and an effective total height 2.2m.Experiments were focused on the effects of entrainers.i.e.acetone.ethanol and ethyl acetate,on the extraction.It is showed that entrainers made selectivity lower,but separation time shorter.     

Determination of Low Erucic Acid Levels in Oils and Fats

In view of requirements set in 1979 by the European Community regarding the reduction of erucic acid levels in foods, we developed a method by which concentrations down to 0.1% can be determined. The procedure and conclusions are discussed in brief.     

The Content of Sulphur Compounds in Solvent Extraction Products of Winter Type Low and High Glucosinolate Rapeseed

Commercially processed seeds and solvent extraction products of low and high glucosinolate rapeseed were analysed from the point of view of sulphur distribution. Glucosinolate and sulphur content were analysed in seeds, while in oils, miscellas and solvents of both varieties sulphur content were determined by tow - the Raney nickel and combustion - procedures. In comparison to traditional rapeseed variety, commercially processed seeds of winter double zero variety contain about 60–70% less of glucosinolates and only 40% less of sulphur. Such a reduction allows to reduce the level of sulphur in double zero rapeseed oil of about 50%.     

低含量氯磺酸的提纯

就氯磺酸生产过程中不可避免产生的含量酸，通过工艺处理，使含量提高，解决了生产中存在的问题，达到有效利用资源的目的。     

The Influence of Reaction Parameters on the Epoxidation of Rapeseed Oil with Peracetic Acid

The influence of reaction parameters on the epoxidation of rapeseed oil (RO) with peracetic acid obtained in situ from the reaction between 30 wt% hydrogen peroxide and glacial acetic acid (AA) has been studied. The course of the reaction was measured by changes of the iodine number (IN) and epoxy number (EN), used to estimate the degree of rapeseed oil conversion, yield, and the selectivity of transformation to epoxidized rapeseed oil in relation to the total amount of oil undergoing the transformation. The optimal conditions of epoxidation are as follows: temperature 60 °C, molar ratio of hydrogen peroxide to rapeseed oil 9.5:1 mol/mol, molar ratio of acetic acid to rapeseed oil 1.12:1 mol/mol, stirring speed 500 rpm, and reaction time of 4 h. Under these conditions the epoxy number is equal to 0.157 mol/100 g RO and iodine number reaches low values of 0.123 mol/100 g RO. The selectivity of transformation to epoxidized RO calculated from EN and IN is 82.2%, conversion of hydrogen peroxide is 100%, conversion of RO calculated from IN is 60.8%, and yield of RO calculated from EN is 50%.     

菜籽油芥酸提取甲酯化工艺研究

研究菜籽油脂肪酸结构、组成特性、提出菜籽油“预酯化－醇馏－蒸馏”工艺路线，试验研究表明，该工艺具有工艺合理、技术易地产品纯度高、收率高、副产品附加值高、投资省。对各种油质包括酸败变质的变酸价油料均可用作原料，综合技术经济效益显著，是一条适合我国国情的芥酸产品开发的有效途径。     

Eco-friendly Pretreatment of Oil with High Free Fatty Acid Content Using a Sulfamic Acid/Ethanol System

In recent years, sulfamic acid (SA, NH₂SO₃H) has emerged as a novel green catalyst for organic synthesis because of several advantages, including its non‐volatility, non‐hygroscopicity, non‐corrosivity, and low cost. This work reports the use of sulfamic acid as a catalyst in the pretreatment of oil with a high content of free fatty acids (10 and 20 % FFA) in ethanol or methanol. The process (esterification reaction) used in the pretreatment of the oil was carried out under a variety of conditions, initial fatty acid content, temperature, type of alcohol, and % catalyst. The experiments using an NH₂SO₃H/ethanol system resulted in a high fatty acid ethyl ester conversion, 88.53 % (±0.95) from an initial acidity of 40 mg KOH/g (20 % FFA), using 8 % NH₂SO₃H as the catalyst. According to the results, the methodology using sulfamic acid and ethanol demonstrated elevated potential for a environmentally‐friendly means of biodiesel production.     

The Effects of High Levels of Fats Rich in Erucic Acid (from Rapeseed Oil) or Cetoleic and Cetelaidic Acids (from Partially Hydrogenated Fish Oil) in a Short-Term Study in a Non-Human Primate Species I

Three experimental groups of primates (cynomolgus monkeys Macaca fascicularis) were adapted to high-fat diets and maintained on the diets for four months. One group (control) was fed a diet containing 25% of lard and corn oil in a 3 : 1 mixture and the other groups received either 25% of rapeseed oil or of partially hydrogenated herring oil. Docosenoic acids were approximately 25% of the rapeseed oil (as erucic acid) and of the partially hydrogenated herring oil (as a mixture of cetoleic acid and cetelaidic acid). Monitoring of physiological parameters did not reveal any important differences between groups. Fecal fatty acids and depot fatty acids showed differences in details of composition from the fatty acids in the diets. These are discussed in terms of intestinal microorganism activity, absorption processes, and in vivo alterations in the primates. In the two experimental groups skeletal and cardiac muscle showed lipidosis. This was especially evident in the apexes of the hearts of animals fed the rapeseed oil and partially hydrogenated herring oil. Fatty acid details from depot fat and cardiac apex triglycerides showed differences and further differences were discerned among the isomeric docosenoic and eicosenoic acids of the cardiac triglycerides. The histopathology of the primate hearts showed a few mild foci of inflammation in all groups which could not be associated with diet, whereas the same diets fed to male weanling rats induced the severe necrotic lesions widely associated with such diets. It is concluded that different species of animals show physiologically different responses to fat-based dietary factors and that further experiments with primates and with oils containing docosenoic acids are required to determine what, if any, cardiac problems exist.     

Thermal Stability of Rapeseed Oil Fortified with Unsaturated Fatty Acid Sterol Esters

The thermal stability of rapeseed oil fortified with 3 % sterol linolenate, sterol linoleate, and sterol oleate was investigated using the Rancimat accelerated oxidation method. The results indicated that the sterol ester content in fortified oil displayed positive correlations (P < 0.05) with total phenols and tocopherols and significant negative correlations (P < 0.05) with acid value (AV), peroxide value (POV), conjugated diene value, \(\varDelta E\) value, viscosity, and polyphenols and γ-tocopherol levels. The sterol ester content in fortified oil was found to significantly decrease when the oil was heated at 110 °C. The rate of increase of the AV, POV, \(\varDelta E\) value, and viscosity, and the rate of decrease of polyunsaturated fatty acid, tocopherol, and polyphenol contents were accelerated with the increase of the degree of unsaturation of fatty acid sterol esters in rapeseed oil during heating. Therefore, the oxidative stability is further reduced by increasing the degree of unsaturation, as the instability of fortified oil is mainly due to the decomposition of unsaturated fatty acid sterol esters. The addition of lipid-soluble polyphenols is an effective method to improve the stability of rapeseed oil fortified with unsaturated fatty acid sterol esters.     

Effect of Substitution of High Stearic Low Linolenic Acid Soybean Oil for Hydrogenated Soybean Oil on Fatty Acid Intake

High stearic, low α-linolenic acid soybean oil (HSLL) has been developed via traditional breeding to serve as a substitute for partially hydrogenated soybean oils used in food manufacturing. The purpose of this study was to estimate the impact on fatty acid intake in the United States if HSLL were substituted for partially hydrogenated soybean oils used in several food categories, including baked goods, shortenings, fried foods, and margarines. Using National Health and Nutrition Examination Survey (NHANES) data (1999–2002), baseline intakes of five fatty acids and trans fatty acids (TFA) were determined at the mean and 90th percentile of fat consumption. Then intakes of these fatty acids were determined after HSLL was substituted for 100% of the partially hydrogenated soybean oils used in these four food categories. The results show that baseline intake of stearic acid is 3.0% energy at the mean and 3.3% energy at the 90th percentile. Use of HSLL could increase stearic acid intake to about 4–5% energy. Mean intakes of TFA could decrease from 2.5 to 0.9% energy, and intake of palmitic acid would remain unchanged. Use of HSLL as a substitute for partially hydrogenated soybean oils would result in changes in the fatty acid composition of the US diet consistent with current dietary recommendations.     

N-油酰基谷氨酸的合成及其在菜籽油中的摩擦学性能研究

将油酸酰氯与谷氨酸在碱性溶液中反应制得N-油酰基谷氨酸,用IR对其结构进行了表征;利用四球磨损试验机考察了植物菜籽油中加入N-油酰基谷氨酸的摩擦学性能,通过测定不同添加含量、不同条件下的最大无卡咬负荷(PB)、烧结负荷(PD)、磨斑直径(WSD)和摩擦系数(μ),分析和研究了载荷、添加剂含量对菜籽油摩擦学性能的影响.试验结果表明,N-油酰基谷氨酸可以显著提高菜籽油的承载能力和抗磨性能,且具有良好的防锈性.