Oxidative stability index of vegetable oils in binary mixtures with meadowfoam oil

The oxidative stability indices (OSI) of several vegetable oils were determined at 110°C. Meadowfoam oil, Limnanthes alba, was found to be the most stable oil with an OSI time of 67.3 h for refined oil and 246.9 h for crude oil. Other oils with good oxidative stabilities were refined high oleic sunflower and crude jojoba oil (Simmondsia chinensis) with OSI times of 49.8 and 34.5 h respectively. The unusually high OSI time of crude meadowfoam oil could not be attributed to its tocopherol content since refining did not significantly alter the tocopherol content, but significantly reduced the stability. A relationship of iodine value to antioxidant was developed for vegetable oils; however, this linear relationship did not account for the unusually high oxidative stability of meadowfoam oil. Binary mixtures of vegetable oils were also examined for enhanced oxidative stability. Small amounts of crude meadowfoam oil gave enhanced oxidative stability in mixtures with jojoba, triolein and castor oils. Triolein/crude meadowfoam oil mixtures showed the most dramatic improvements in OSI time with a 5% (w/w) addition of crude meadowfoam causing a 21-fold increase in the OSI time. Meadowfoam mixtures with jojoba improved the OSI time of jojoba from 31.1 to 52.7 h, when 10% crude meadowfoam oil was added. A study of oxidative stability with respect to olefin position showed that the Δ5 double bond was the most stable by more than an order of magnitude. The oxidative stability of meadowfoam FAMEs at 90°C gave an OSI time of 4.9 h which was the same as methyl erucate and methyl petroselenate, but less than methyl oleate which had an OSI time of 14.8 h. However, when methyl 5-eicosenoate was isolated in high purity (monoene >96%) and tested, it gave an OSI time of 69.4 h.     

Lubricant basestocks from vegetable oils

Compared to the lubricants made of petroleum, vegetable-based lubricants are much more biodegradable but inferior in many other technical characteristics. The basestock typically contributes to more than 80% of lubricant and must meet performance criteria in such aspects as cleanliness, viscometric properties, volatility, oxidative and hydrolytic stability, deposit forming tendencies, solvency, miscibility or compatibility with system elastomers and other. For vegetable-based lubricants, oxidative stability and low temperature problems are considered the most critical. Thin film oxidation test was used to compare oxidative stabilities. Vegetable oils appear an order of magnitude less stable than mineral oils or synthetic biodegradable basestocks, such as isoalkyl adipates or poly alphaolefins. Low temperature performance of vegetable oils, namely pour points and cold storage, was also problematic. These problems can only partially be relieved by lubricant additives, thus vegetable oils have to be modified chemically to eliminate sites susceptible to oxidation and to disrupt formation of crystals at low temperatures.     

Synthetic lubricant basestocks from epoxidized soybean oil and Guerbet alcohols

Vegetable oils are biodegradable and therefore good candidates for environmentally friendly base stocks. They have excellent lubricity, but poor oxidation and low temperature stabilities. For this study, synthetic lubricant basestocks with oxidative stabilities and pour points comparable with commercial synthetic lubricant basestocks have been prepared by reacting epoxidized soybean oil with Guerbet alcohols. Four different Guerbet alcohols, C12-, C14-, C16-, and C18-Guerbet alcohols were used. Reaction of epoxidized soybean oil with a Guerbet alcohol in the presence of a catalytic amount of sulfuric acid provided open-ringed products. ¹H NMR has shown that transesterification follows after ring-opening reaction under the given reaction conditions. Two types of ring-opened products, 0%- and 100%-transesterified products, could be obtained under controlled reaction conditions. Pour points of the ring-opened products ranged from −18 to −36 °C without pour point depressant (PPD) and from −21 to −42 °C with 1% of PPD. Acetylation of hydroxy groups in the ring-opened products further lowered pour points that ranged from −27 to −42 °C without PPD and from −30 to −48 °C with 1% of PPD. Oxidative stability was examined using a modified Penn State microoxidation test and compared with those of synthetic lubricant basestocks and mineral oil. Oxidative evaporations of two selected products in the microoxidation test were similar to mineral oil and less than synthetic lubricant-based oils, polyalphaolefin (PAO₄) and diisododecyl adipate. Deposits of these products were similar to synthetic lubricant-based oils and less than mineral oil.     

Epoxidized soybean oil as a potential source of high-temperature lubricants

Development and application of biocompatible lubricants are increasing daily as a result of stringent regulations imposed on mineral oil-based lubricants with their non-biodegradable toxic wastes. Before consumer acceptance of vegetable oil-based lubricants, they must overcome certain poor performance characteristics such as thermal and oxidative instabilities. This work demonstrates the improved performance of epoxidized soybean oil (ESBO) over soybean oil (SBO) and genetically modified high oleic soybean oil (HOSBO) in certain high temperature lubricant application. We validated the thermal and deposit forming tendencies of these oils using micro-oxidation and differential scanning calorimetry in conjunction with identification of oxidized products by infrared spectroscopy and also discussed the function of a phenolic antioxidant in these oils. Boundary lubrication properties under high load and low speed were determined and the variations explained based on the structural differences of these vegetable oils.     

Effect of bio-friendly conditioning agents on jute fibre spinning

From early times, jute fibre has been generally conditioned for easy spinning by adding oil and water in the form of an emulsion. The commonly used oil consists of C₁₂–C₃₁ fractions of mineral oil that sometimes impart different intensities of oily (kerosene) or fishy smell to the end product. In the present work, efforts have been made to find a suitable sustainable substitute of mineral oil based conditioning agent for spinning of jute yarn and for this, three types of vegetable oil (rice bran oil, palmolein oil and castor oil), a silicone emulsion, a mixed enzyme system and glycerine have been used separately or in combinations as conditioning agents for jute fibre before its mechanical processing for making yarn in jute spinning machines. Considering comparable mechanical process performance for spinning of jute fibre (viz., fibre loss as droppings during processing, moisture retention prior to spinning stage and spinning end breakage rate), tensile properties of yarn, and lower yarn hairiness, it may be suggested to use 2.5% castor oil alone, or 2% castor oil in combination with 0.1–0.5% glycerine in the form of oil-in-water emulsion as the most suitable alternatives to conventional mineral oil-based jute conditioning agent to spin ordinary jute yarn.     

Proximate Composition and Functional Properties of Fullfat and Defatted Beniseed (Sesamum Indicum L.) Flour

The proximate composition and functional properties of fullfat and defatted beniseed (Sesamum indicum L.) flour were evaluated. Functional properties studied were foam capacity and stability, water and oil absorption, bulk density, emulsion capacity and nitrogen solubility. Defatting increased the crude protein, ash, crude fiber, carbohydrate and mineral contents. Defatted flour showed comparatively better foam capacity and stability, water absorption and emulsion capacities but diminished bulk density and oil absorption capacity. Nitrogen solubility was pH dependent with a minimum at pH 4 and maximum at pH 8. Maximum nitrogen solubility (95%) was recorded for defatted flour while that for the fullfat flour was 60%. The proximate composition and functional properties of the samples suggest that beniseed flour would have useful application in fabricated foods.     

Synthesis of novel alkoxylated triacylglycerols and their lubricant base oil properties

Development and application of bio-based fluids in industrial and automotive sectors are rapidly increasing due to their non-toxic and biodegradable character unlike mineral oil-based products. Synthetic lubricant base fluid with improved high and low-temperature stability was prepared by chemical modification of epoxidized soybean oil (ESBO). The reaction was carried out in two-steps: (i) synthesis of dihydroxylated soybean oil from ESBO with HClO₄, (ii) reaction of acetic, butyric and hexanoic anhydride with the dihydroxylated product. The composition of the reaction products were confirmed by NMR and FTIR analysis. Chain length variation of the anhydrides used in the synthesis resulted in base fluids with different physical and chemical properties. Low-temperature stability was excellent for hexanoic anhydride derivative. When compared with SBO, thermal and oxidative stabilities were improved. Viscosity, volatility and other lubricant base oil properties were evaluated qualitatively. Bio-fluids based on this chemical modification offer great potential for the development of industrial fluids and products based on such fluids.     

Viscosity reduction of castor oil esters by the addition of diesel, safflower oil esters and additives

The high viscosity of vegetable oil can be reduced by transesterification with alcohols and converting it into biodiesel. Biodiesel can be used neat or blended with diesel as engine fuel. This study demonstrates that esters of castor oils have a higher viscosity than safflower oil derived esters and the viscosity can be reduced by blending with diesel. The viscosity increased in a non-linear fashion as the percentage of castor esters increased in castor esters diesel blends and in castor esters safflower esters blends. Only slight increases in viscosity were observed for B40 and B60 mixtures with No. 2 diesel. Addition of ten chemical additives in castor esters at the rate of 0.01%, 0.1% and 1.0% showed limited viscosity reduction.     

Management of Bemisia tabaci biotype B with botanical and mineral oils

While the toxic effects of neem, Azadirachta indica A. Juss, on Bemisia tabaci Genn. are well documented, few studies have evaluated other oils. We compared neem, sesame, citrus, castor, vegetable and mineral oils (1% v/v) to a chemical standard thiamethoxam (0.17 g A.I./L) against B. tabaci biotype B life stages on dry bean plants Phaseolus vulgaris L. under screenhouse conditions. Oils and thiamethoxam exhibited low ovicidal activity (<10% egg mortality). However, significant mortality occurred due to the residual activity to 1st instars that emerged from treated eggs. Overall, impacts of egg treatments were greatest for thiamethoxam (77% total mortality for eggs and 1st instars) compared with oils which were statistically similar (22–29% mortality). Larvicidal effect of oils (against 2nd instars) was greater than ovicidal effects. Highest nymphal mortality (>81%) was achieved with castor, sesame, citrus and neem oils, which was significantly greater than for thiamethoxam (65% mortality). Adult whiteflies were exposed to fresh and aged spray residues, rather than being sprayed directly. In this case, comparatively lower efficacy was achieved from oil treatments compared with thiamethoxam. While some mortality was observed from fresh residues of slow drying oils (up to 41% for castor oil), no significant control from any oil residues >3 days old was observed in our tests. The different route of exposure against adults likely reduced the effectiveness of oil treatments which act directly on the cuticle. In trials with viruliferous adult whiteflies exposed to fresh residues, none of the tested products completely prevented transmission of bean golden mosaic virus (BGMV). However, we noted reduced virus severity ratings from plants pre-treated with castor and citrus oil. We conclude that castor, sesame, citrus and neem oils have the potential to be used in whitefly management programs.     

Quality attributes and storage stability of locally and mechanically extracted crude palm oils in selected communities in Rivers and Bayelsa States,Nigeria

The effect of different extraction methods on the qualityof crude palm oil processed using traditional (local) and mechanical methods in selected areas of Rivers and BayelsaStates and their storage stability were investigated.Certain quality determining parameters such as free fatty acids (FFA), peroxide value (PV), saponification value (SV),moisture, impurities and volatile matter (MIV) content weredetermined prior to and after storage for three months. The free fatty acids (FFA) ranged from 7 to 19 percent, peroxidevalue (PV) ranged from 3 mEq/kg to 6 mEq/kg and moisture, impurity and volatile matter (MIV) ranged from 0.21 to 0.64 percent for locally extracted crude palm oil samples and mechanically extracted crude palm oil samples. There was no significant difference (p > 0.05) in the FFA of samples A and E before and after storage for 3 months. Also two of thelocally extracted crude samples (A and E) stored better whileone of the samples (D) showed a high level of deteriorationas shown in its high levels of FFA, PV and IV values. SamplesA and E resulted in a better quality of oil in terms of FFA (av. 7.25%) and PV (av. 4.5 meg/kg) when compared to the mechanically extracted one (sample C) with FFA (10.0%) and PV (5.78 mEq/kg). However, all the locally and mechanically extracted crude palm oil samples could not meet the industrial and international standard quality for crude palm with FFA (2–5%) and PV (2–3.5 mEq/kg). Among the three different storage containers used under different storage conditions, plastic containers (PC) resulted in a better storage stability of the crude palm oils in terms of FFA, SV, and IV than transparent bottles stored on shelves (TBS) and amber-coloredbottles stored on the bare floor (BPF).     

Increasing oxidative stability in corn oils through extraction of γ-oryzanol from heat treated rice bran

Corn oil was mixed with heated rice bran with different extraction periods and ratios of rice bran to corn oil to extract γ-oryzanol from rice bran. Selected corn oils based on the content of γ-oryzanol were heated at 180 °C for 100 min or 60 °C for 16 days, and oxidative stability was evaluated. Corn oils recovered from the mixture of rice bran showed higher oxidative stability at both 60 and 180 °C treatment compared to control corn oils. At 180 °C, corn oils of a 1:5 ratio of rice bran to corn oil (w/w) showed higher oxidative stability than did those of 1:3 and 1:7 (w/w), whereas at 60 °C, corn oils of 1:7 (w/w) showed higher oxidative stability than did others. γ-Oryzanol can be extracted through a corn-oil mixture at 80–90 mg/100 g oil, which is about 4.0% recovery of 2244 mg/100 g crude rice-bran oil. Oxidative stability of corn oils increased significantly, partly because of the extraction of γ-oryzanol under current experimental conditions.     

Castor oil-based lubricant reduces smoke emission in two-stroke engines

Smoky emissions from two-stroke gasoline engines (2T) are a problem for the environment. Use of vegetable oil (oxygenate) is one solution. A biodegradable 2T-oil was developed from castor oil, which consisted of tolyl monoesters and performance additives but no miscibility-solvent. Evaluation revealed that on one hand it reduced smoke by 50-70% at 1% oil fuel ratio and on the other hand it was at par with standard product specification. Starting problems, piston-seizer or any other driving problems were not observed during the test. There is excellent potential for castor oil based biodegradable 2T-lubricant as a smoke pollution reducer.     

Characterization of castor oil/polycaprolactone polyurethane biocomposites reinforced with hemp fibers

Abstact  The thermal and mechanical properties of castor oil/polycaprolactone-based polyurethane (CPU) films and polyurethane biocomposites reinforced with hemp fibers (HCPU) were investigated. Although similar films can be synthesized from petroleum, the main interest in studying these biomass-based composites is based on the fact that both fiber and matrix are derived from renewable resources. In this study, castor oil was used as a polyol for polyurethane films and hemp fiber was used to reinforce the biocomposites. To control the mechanical properties of CPU and HCPU, polycaprolactone diol (PCL) was added to the polyol mixture. Varying the mixing ratio of castor oil and PCL, the thermal and mechanical properties of the CPU and HCPU samples were investigated by using FT-IR, DSC, DMTA, Minimat, and SEM. In an attempt to improve interfacial adhesion between the fiber and matrix biocomposites, hemp fiber was reacted with MDI. FE-SEM micrographs showed that the surface of the hemp fiber became smoother after reaction with MDI. Urethane bonding formation was confirmed by FT-IR.     

Synthesis and characterization of hazelnut oil-based biodiesel

The demand for diesel fuel far exceeds the current and future biodiesel production capabilities of the vegetable oil and animal fat industries. New oilseed crops that do not compete with traditional food crop are needed to meet existing energy demands. Hybrid hazelnut oil is just such an attractive raw material for production of biodiesel. Hazelnut oil was extracted from hybrid hazelnuts and the crude oil was refined. Hazelnut oil-based biodiesel was prepared via the transesterification of the refined hazelnut oil with excess methanol using an alkaline catalyst. The effects of reaction temperature, time and catalyst concentration on the yield of diesel were examined, and selected physical and chemical properties of the biodiesel were evaluated. The biodiesel yield increased with increasing temperature from 25 to 65 °C and with increasing catalyst concentration from 0.1 to 0.7 wt%. The increase in yield with reaction time was nonlinear and characterized by an initial faster rate, followed by a slow rate. Hazelnut oil-based biodiesel had an average viscosity of 8.82 cP at 25 °C, which was slightly higher than that of the commercial soy-based diesel (7.92 cP at 25 °C). An approximate 12 °C higher onset oxidative temperature and a 10 °C lower cloud point of hazelnut oil biodiesel than those of its commercial soy counterpart indicated a better oxidative stability and flowability at low temperature. The average heat of combustion of hazelnut oil biodiesel was 40.23 kJ/g, and accounted for approximately 88% of energy content of diesel fuel. The fatty acid composition of hazelnut oil-based biodiesel was the same as the nature oil.     

Physical and chemical characteristics of refined vegetable oils from rubber seed (Hevea brasiliensis) and bread-fruit (Artocarpus altilis)

Crude vegetable oil obtained by solvent extraction from rubber seed (Hevea brasiliensis) and breadfruit (Artocarpus altilis) were subjected to alkali refining (neutralisation), degumming and bleaching. At each stage of refining, the crude and the refined oil were analysed for their physical and chemical characteristics notably specific gravity, moisture and volatile matter content, saponification, iodine values, peroxide value, unsaponifiable matter, fatty acids and free fatty acids. Results showed an improvement in the quality of the oil after refining. Refining decreased the free fatty acids and peroxide value, which are some of the characteristics that determine stability. There was a very slight decrease in saponification value and unsaponifiables matter after refining. Refining did not have much effect on the fatty acid composition except slight nonconsistent decreases in saturated and unsaturated fatty acids. There was no decrease in iodine value.     

以橡胶木屑为主要基质栽培的大球盖菇与香菇、平菇的主要营养成分差异

本研究将以橡胶木屑为主栽培的大球盖菇与常见食用菌的营养成分进行比较，以期从营养的角度为推广橡胶-大球盖菇模式提供依据。以常见的香菇和平菇为对照，比较大球盖菇的三大类营养成分、功能性成分、矿质元素和氨基酸的含量与香菇和平菇的养分差异。结果表明，与香菇和平菇相比，大球盖菇中占比最大的粗蛋白、总糖、氨基酸总量分别比香菇和平菇高 35.4%和 30.3%，52.7%和 21.3%，58.3%和 45.6%；占比较小的粗脂肪、粗多糖、总黄酮、粗纤维、矿质元素则总体持平或略低。综上所述，以橡胶木屑栽培为主栽培的大球盖菇的营养总体上较丰富，是推广橡胶-大球盖菇模式的有利依据之一。     

Synthesis of a new thiophosphorylated compound derived from cashew nut shell liquid and study of its antioxidant activity

This work describes the synthesis and study of the antioxidant activity in mineral oils of new thiophosphorylated compound derived from cashew nut shell liquid (CNSL), a by-product of the process of improvement of cashew nuts. This study was conducted through the thermal analysis observing the T_onset variations and the accelerated oxidation experiments observing the induction time variations. The results of thermogravimetric and acceleration oxidative experiments showed a significant improvement in the oxidative stability of the doped oils. These results suggest that this new compound acts efficiently in the stabilization of the naphthenic mineral oils.     

Lipid profile of rats fed blends of rice bran oil in combination with sunflower and safflower oil

This study was undertaken to assess the effect of blended oils, i.e., polyunsaturated fatty acid (PUFA) rich vegetable oils like safflower oil (SFO) and sunflower oil (SNO) with the unconventional and hypocholesterolemic rice bran oil (RBO) on the serum lipid profile of rats. Rats fed RBO + SNO/SFO at 70:30 ratio for a period of 28 days showed significantly (p < 0.05) lower levels of total cholesterol (TC), triglycerides (TG) and low density lipoprotein (LDL) cholesterol and increased high density lipoprotein (HDL) cholesterol in animals fed a high cholesterol diet (HCD) and cholesterol free diet (CFD). Liver total cholesterol (TC) and triglycerides (TG) were also reduced. Fecal excretion of neutral sterols and bile acids was increased with use of RBO blends. RBO, which is rich in tocopherols and tocotrienols, may improve the oxidative stability of the blends. Tocotrienols are known to inhibit 3-hydroxy, 3-methyl, glutaryl CoA (HMG-COA) reductase (rate limiting enzyme in cholesterol biosynthesis), resulting in hypocholesterolemia. In addition to improving the lipid profile by lowering TC, TG and LDL-C and increasing HDL-C, blending of RBO with other oils can result in an economic advantage of lower prices.     

不同干燥工艺下脱皮油莎豆干燥特性及品质研究

采用先湿法脱皮再干燥的方式可以简化油莎豆榨油前工序，提高榨油效率。为探究最适合的干燥工艺，本文以湿法脱皮油莎豆为研究对象，探究其薄层热风干燥特性，对比分析不同干燥工艺下脱皮油莎豆品质及所制取油脂的品质变化规律，以期为油莎豆产业化发展提供支持。本实验分别将油莎豆在自然干燥以及热风温度为50℃、60℃、70℃，风速0.8 m/s条件下进行干燥，再测定油莎豆的色泽、硬度、复水性以及脱皮油莎豆所制取油脂的品质。实验结果显示，样品干燥后亮度值、泛红度降低，硬度升高；热风50℃样品复水性最好，自然干燥次之，热风70℃下样品复水性最差；热风干燥条件下，随着风温的升高，所制得的油莎豆油的酸价及过氧化值均呈增加趋势，但是远低于国家标准中对食用植物油的要求。     

Lesquerella fendleri response to different sowing dates in northern Mexico

Lesquerella fendleri (Gray) Wats. is a Brassicaceae native to northern Mexico and southern United States. The seeds contain an oil similar to castor oil that may be used for a wide array of industrial products. The U.S. imports 41,000 t of castor oil per year. Thus, Lesquerella oil may be an economic replacement for castor oil. The Mexican growers in the semiarid lands have the potential for cultivating Lesquerella if the crop can be grown in the native regions. The object of this study is to determine the effect of sowing date on seed yield and oil content in Lesquerella grown at Saltillo located in northern Mexico. The plants were sown at three different dates (23 October 2003, 16 December 2003, and 17 March 2004) and harvested in 2004 on 15 May, 24 June, and 27 August, respectively. Irrigation was applied for germination and seedling establishment and to maintain soil moisture. The experimental design was a complete randomized block design with eight replications. Plant morphological variables as well as yield characteristics were measured and related to sowing dates and climatic conditions. The longer period for crop development was due to shorter photoperiod. Plant densities were highest when the crop was sown in December and March, although the densities of three sown dates were within the reported limit for high yield. Seed yield was highest when the crop was sown in December and the oil content increased in the March planting when the mean temperature during seed formation was highest. Infrared spectra of the seeds crude extracts showed different functional groups that varied with climatic conditions.