Showing papers on "Soybean oil published in 1999"

Biodiesel production via acid catalysis

Abstract: Vegetable oils and animal fats can be transesterified to biodiesel for use as an alternative diesel fuel. Conversion of low cost feedstocks such as used frying oils is complicated if the oils contain large amounts of free fatty acids that will form soaps with alkaline catalysts. The soaps can prevent separation of the biodiesel from the glycerin fraction. Alternative processes are available that use an acid catalyst. The objective of this study was to investigate the effect of process variables on acid-catalyzed transesterification. The molar ratio of alcohol, reaction temperature, catalyst amount, reaction time, water content, and free fatty acids were investigated to determine the best strategy for producing biodiesel. Food grade soybean oil was used to prepare esters using excess methanol and sulfuric acid as a catalyst. To compare the effect of different alcohol types on ester formation, methanol, ethanol, 2-propanol, and n-butanol were compared. The American Oil Chemists’ Society Method Ca 14-56 was used to measure the biodiesel’s total glycerin amount as an indicator of the completeness of the reaction. It was found that acid catalysis can provide high conversion rates but much longer times are required than for alkaline catalysts. The acid catalyst also requires the concentration of water to be less than 0.5%, which is about the same as is required for alkaline catalysts. Water formed by the esterification of free fatty acids limited their presence in the oil to 5%.

Conversion of vegetable oil to biodiesel using immobilized Candida antarctica lipase

Abstract: Biodiesel derived from vegetable oils has drawn considerable attention with increasing environmental consciousness. We attempted continuous methanolysis of vegetable oil by an enzymatic process. Immobilized Candida antarctica lipase was found to be the most effective for the methanolysis among lipases tested. The enzyme was inactivated by shaking in a mixture containing more than 1.5 molar equivalents of methanol against the oil. To fully convert the oil to its corresponding methyl esters, at least 3 molar equivalents of methanol are needed. Thus, the reaction was conducted by adding methanol stepwise to avoid lipase inactivation. The first step of the reaction was conducted at 30°C for 10 h in a mixture of oil/methanol (1:1, mol/mol) and 4% immobilized lipase with shaking at 130 oscillations/min. After more than 95% methanol was consumed in ester formation, a second molar equivalent of methanol was added and the reaction continued for 14 h. The third molar equivalent of methanol was finally added and the reaction continued for 24 h (total reaction time, 48 h). This three-step process converted 98.4% of the oil to its corresponding methyl esters. To investigate the stability of the lipase, the three-step methanolysis process was repeated by transferring the immobilized lipase to a fresh substrate mixture. As a result, more than 95% of the ester conversion was maintained even after 50 cycles of the reaction (100 d).

Isolation and characterization of a thermophilic lipase from Bacillus thermoleovorans ID‐1

Abstract: A thermophilic microorganism, Bacillus thermoleovorans ID-1, isolated from hot springs in Indonesia, showed extracellular lipase activity and high growth rates on lipid substrates at elevated temperatures. On olive oil (1.5%, w/v) as the sole carbon source, the isolate ID-1 grew very rapidly at 65°C with its specific growth rate (2.50 h−1) and its lipase activity reached the maximum value of 520 U l−1 during the late exponential phase and then decreased. In addition to this, isolate ID-1 could grow on a variety of lipid substrates such as oils (olive oil, soybean oil and mineral oil), triglycerides (triolein, tributyrin) and emulsifiers (Tween 20, 40). The excreted lipase of ID-1 was purified 223-fold to homogeneity by ammonium sulfate precipitation, DEAE-Sephacel ion-exchange chromatography and Sephacryl S-200 gel filtration chromatography. As a result, the relative molecular mass of the lipase was determined to be 34 kDa on sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). The enzyme showed optimal activity at 70–75°C and pH 7.5 and exhibited 50% of its original activity after 1 h incubation at 60°C and 30 min at 70°C and its catalytic function was activated in the presence of Ca2+ or Zn2+.

Temperature and cultivar effects on soybean seed oil and protein concentrations

Abstract: The soybean [Glycine max (L.) Merr.] industry is interested in cultivar and climate effects on seed composition. These factors may underlie the known geographic variation in seed protein and oil concentrations. Regression analyses were used to test hypotheses of the effect of temperature and cultivar on oil and protein concentrations of soybean seed using a large data set from the U.S.A. Soybean Uniform Tests. The data set included 20 cultivars representing 10 maturity groups across 60 locations (latitude 29.4 to 47.5° N) for a total of 1863 cultivar by location by year observations. Temperature was determined for each observation as the average daily mean temperature from predicted first pod (first pod at least 5 mm long), using the SOYGRO phenology model, to observed maturity. The mean temperature ranged from 14.6 to 28.7°C among the observations. Linear, quadratic, and linear plateau regression models of oil and protein concentrations vs. temperature were evaluated. The quadratic model gave the best-adjusted R 2 values for oil and protein with temperature, of 0.239 and 0.003, respectively. The analyses showed that the oil concentration increased with increasing temperature and approached a maximum at a mean temperature of 28°C. Unaccounted variation in the protein concentration may be from other factors such as photoperiod, water stress, or high temperatures during seed fill. Protein plus oil had a linear relationship with temperature (adjusted partial R 2=0.183). These data document the contribution of climate and cultivar to geographic variability of oil and protein concentrations in the United States.

Depression of pour points of vegetable oils by blending with diluents used for biodegradable lubricants

Abstract: Low-temperature properties need improvement before vegetable oils can receive wider recognition as biodegradable lubricants. Effects of dilution with major biodegradable fluids, namely poly alpha olefin (PAO 2), diisodecyl adipate (DIDA), and oleates, as well as impact of pour point depressant (PPD), were investigated. Since solidification of mixed unsaturated triacylglycerols is a complex thermodynamic process, the study was limited to pour point determinations. Vegetable oils demonstrated higher pour points with increased saturation and molecular weight. Cis unsaturation and hydroxy groups favored lower pour points. Dilution with oleates appeared less effective than dilution with PAO 2 and DIDA. Addition of 1% PPD (w/w) depressed pour points down to −33°C for canola and −24°C for high-oleic sunflower oils. However, neither higher amounts of PPD nor incorporation of diluent produced further depression. Depression of pour points was not proportional to the amount of diluent and ceased with further dilution. Low-temperature performance of vegetable oils limits their prospect as biodegradable lubricants, but well-balanced usage of PPD and diluents can deliver some improvements.

Tocopherols in breeding lines and effects of planting location, fatty acid composition, and temperature during development

Abstract: As the use of tocopherols as natural antioxidants increases, it is economically and agronomically important to determine the range, composition, and factors that affect their levels in oilseed crops, a major commercial source. In this study, tocopherols were quantified from seeds of wheat, sunflower, canola, and soybean. The breeding lines analyzed possessed a broad range of economically important phenotypic traits such as disease or herbicide resistance, improved yield and agronomic characteristics, and altered storage oil fatty acid composition. Complete separation of all four native tocopherols was achieved using normal-phase high-performance liquid chromatography with ultraviolet detection. Total tocopherol concentration among wheat germ oil samples ranged from 1947 to 4082 µg g−1. Total tocopherol concentration ranges varied from 534 to 1858 µg g−1 in sunflower, 504 to 687 µg g−1 in canola, and 1205 to 2195 µg g−1 among the soybean oils surveyed. Although the composition of tocopherols varied substantially among crops, composition was stable within each crop. Total tocopherol concentration and the percentage linolenic acid were correlated positively in soybean oils with modified and unmodified fatty acid compositions. Tocopherol concentration and degree of unsaturation were not correlated in sunflower or canola seeds with genetically altered fatty acid composition. These findings suggest that breeding for altered storage oil fatty acid composition did not negatively impact tocopherol concentrations in sunflower and canola as they apparently did in soybeans. When 12 soybean breeding lines were grown at each of five locations, significant correlations were observed among planting location, breeding line, tocopherol concentration, and fatty acid composition. Analysis of seeds that matured under three different controlled temperature regimes suggests that the relationship between tocopherol concentration level and unsaturated fatty acids in commodity (not genetically modified for fatty acid composition) oil types is due to temperature effects on the biosynthesis of both compounds.

Antioxidant activity in soybean oil of extracts from thompson grape bagasse

Abstract: The phenolic compounds of Thompson grape bagasse were extracted using a 95:5 (vol/vol) ethanol/water mixture. Measurement of the antioxidant activity in refined soybean oil of bagasse grape extract was performed by using two different methods, the Rancimat method and the Schaal oven method in conjunction with peroxide value determination. The antioxidant activity of the extract was compared to the tertiary butyl hydroquinone (TBHQ) and butylated hydroxyanisole (BHA) activity. The bagasse grape extract showed similar antioxidant activities in both methods employed. At all concentrations tested [0.1, 0.3 and 0.5% of total phenols (TP)] the extract exhibited appreciable activity, which exceeded the activity of BHA. At some concentrations (0.3 and 0.5% TP) the extract exhibited activity comparable to that of TBHQ. Bagasse is a byproduct with a high content of phenolic compounds and is a good source of natural antioxidants.

The Evaluation of Frying Oils with the p-Anisidine Value

Abstract: This study was conducted to examine the relationship of p-anisidine value with headspace volatiles, sensory evaluation, and polymers. Partially hydrogenated soybean frying oil was used to fry shoestring potatoes. The oil was evaluated by p-anisidine value, headspace volatile analysis, sensory evaluation, and polymer analysis. p-Anisidine value was found to be correlated with hexanal (r=0.81), heptanal (r=0.66), t-2-hexenal (r=0.81), t-2-heptenal (r=0.71), t-2-octenal (r=0.92), and t,t-2,4-decadienal (r=0.86) contents. p-Anisidine value was correlated with overall odor intensity (r=0.82) and correlated with fried food odor (r=0.53) and burnt odor (r=0.43). p-Anisidine value and polymers were also correlated (r=0.84).

Ruthenium-catalyzed metathesis of vegetable oils

Abstract: A new process for the acyclic diene metathesis of vegetable oils utilizing Grubbs’ ruthenium catalyst (Cy3P)2Cl2Ru = CHPh has been developed. The higher molecular weight oligomers obtained can be separated from the unreacted oil and the lower molecular weight alkene by-products easily. The reaction proceeds in the absence of solvent, with very low catalyst concentrations (0.1 mole %) under moderate temperatures and low pressures. This process does not require the stringent exclusion of water and oxygen that the previous method (Me4Sn plus WCl6) required. Low pressures appear to favor polymerization by removing the alkene by-products. The metathesis reaction has been shown to be effective for many unsaturated vegetable oils, although some cases require oil pretreatment with silica gel. This process is effective on a 2–200 g scale. Chromatographic separation and characterization of metathesized soybean oil indicate that the process involves intermolecular and intramolecular carbon-carbon double-bond formation.

Effect of genetic modification on the distribution of minor constituents in canola oil.

Abstract: Oil derived from different lines of genetically modified canola varieties was analyzed for phospholipids, tocopherols, and phytosterols by various chromatographic techniques. As observed previously in genetically modified soybean oils, there was a decrease in the content and composition of phosphatidic acid in three of the modified canola oils derived from the 12 varieties investigated. Normal-phase high-performance liquid chromatographic (HPLC) analyses showed small variations in the phospholipid content of major classes, despite few differences in their composition. Reversed-phase HPLC data indicated that the molecular species distribution of phosphatidylethanolamine was significantly altered by genetic modification when compared to phosphatidylcholine. Impact of oilseed modification on the tocopherol content was variable, with greater variation in the concentration of α- and γ-tocopherols than δ-tocopherol. Phytosterol composition was markedly affected by genetic modification. Brassicasterol, campesterol, and β-sitosterol levels were consistently lowered in one genotype, whereas increased brassicasterol content was observed in the other variety. In general, genetic modification of canola seeds led to changes in the distribution of phospholipids, tocopherols, and phytosterols.

Alkylguanidine-catalyzed heterogeneous transesterification of soybean oil

Abstract: Transesterification of soybean oil with methanol has been carried out in the presence of heterogenized alkylguanidines as catalysts. The alkylguanidines were anchored to modified polystyrene or siliceous MCM-41, encapsulated in the supercages of zeolite Y, or entrapped in SiO 2 sol-gel matrices. The catalytic activity of these catalysts was compared with that of their homogeneous counterparts, showing that the yields of methyl esters obtained in the homogeneous phase can be obtained with the guanidines anchored to the supports after longer reaction times. The catalysts prepared by immobilization of alkylguanidines in microporous systems showed diffusion restrictions for the vegetable oil as well as the low stability of the inorganic framework.

Mechanical Oil Expression from Extruded Soybean Samples

Abstract: Soybean is generally recognized as a source of edible and industrial oil, and the deoiled meal is seen as a source of protein in animal feed. In recent years, however, more interest has been directed toward using soy meal as a protein source for human consumption. Extrusion-expelling of soybean provides an opportunity in this direction. The main focus of this study was to maximize the oil recovery from extruded soybean processed using three different kinds of extruders and processing conditions. These extruded samples were later pressed uniaxially in a specifically designed test-cell and the oil recovery was recorded over time. The effects of process variables, including applied pressure, pressing temperature and sample height, were investigated. Results indicated that over 90% of the available oil could be recovered from pressing of extruded soy samples. The information generated is likely to be useful in interpreting the effect of process variables and extruding equipment for pretreatment of soybean for subsequent mechanical oil expression.

Effects of soybean oil emulsion and eicosapentaenoic acid on stress response and immune function after a severely stressful operation.

Abstract: ObjectiveTo investigate the effects of soybean oil emulsion and oral or enteral administration of eicosapentaenoic acid (EPA) on stress response, cytokine production, protein metabolism, and immune function after surgery for esophageal cancer.Summary Background DataIt has been reported that safflowe

Quality changes of refined‐bleached‐deodorized (rbd) palm olein, soybean oil and their blends during deep‐fat frying

Abstract: The quality changes of refined, bleached and deodorized palm olein (RBDPO) and soybean oil (SBO) and their blends were investigated in this study. The oils were studied during intermittent frying of potato chips at 180PT5C for 5 h per day for 5 consecutive days. The indices used for assessment of changes in quality of the oils were fatty acid composition (FAC), peroxide value (PV), anisidine value (AnV), % free fatty acid (FFA), iodine value (IV), % polar component, polymer content, color, viscosity, smoke point and foaming tendency. The results showed that RBDPO was superior to SBO in frying performance in terms of resistance to oxidation, changes in IV, AnV, foaming tendency, % polar component and polymer content. However, SBO performed better than RBDPO with respect to color, viscosity, FAA content and smoke point. Sensory evaluation showed that potato chips fried in both RBDPO and SBO were equally acceptable by the panelists.

Quantitative differential scanning calorimetric analysis for determining total polar compounds in heated oils.

Abstract: A new differential scanning calorimetry (DSC) method was developed for the determination of total polar com- pounds (TPC) in heated oils. Three different types of edible oils, refined, bleached, and deodorized corn oil (CO), palm olein (RBDPO), and soybean oil (SO), were used in this study. Each type of edible oil was heated at 180°C in a deep fryer to obtain a range of TPC concentrations. In this study, the cooling ther- mograms of oil samples at a scanning rate of 1°C/min from −30 to −85°C showed a well-defined single crystallization peak. The study found that six DSC parameters, namely, peak temperature (PT), enthalpy (EN), onset (ON) and offset (OF) temperatures, peak height (HT), and the range of temperatures (RT) (the differ- ence between onset and offset temperature) of this single crys- tallization peak could predict well the TPC of heated oils by using stepwise multiple linear regression analysis. These six pa- rameters were used as independent variables while values from standard method were used as dependent variables. The coeffi- cient of determination (R 2 ) of calibration models for CO, RBDPO, and SO were 0.9996, 0.9709, and 0.9980, respec- tively. Calibration models were validated with an independent set of samples. The R 2 of validation models were 0.9995, 0.9559, and 0.9961, respectively. Based on the results ob- tained, DSC appears to be useful instrumental method in deter- mining the TPC of edible oils, and it may have the potential to replace the time- and chemical-consuming standard method. Paper no. J9073 in JAOCS 76, 1047-1057 (September 1999).

Effect of physical refining on selected minor components in vegetable oils

Abstract: The final quality of vegetable oils is largely determined by the deodorization process From an organoleptic point of view, oils should be light in color with a bland taste and a good cold and/or oxidative stability Today, however, more and more attention is paid to the real nutritional quality Oils should contain low trans fatty acid levels, low polymeric triglycerides, and secondary oxidation products and at the same time being rich in natural antioxidants In order to comply to these new quality requirements, the deodorization technology has been modified substantially Mathematical models were established describing the influence of different process parameters (time, temperature, steam, and pressure) on trans fatty acid formation, tocopherol stripping, and production of oxidized and polymeric triacylglycerides during physical refining of soybean oil Trans fatty acid (TFA) formation was influenced only by time and temperature No significant influence of pressure or sparging steam could be observed Models expressing the relative degree of cis/trans-isomerization of linoleic (DI 18:2 ) and α-linolenic acid (DI 18:3 ) could be extra-polated to other oils and deodorizer designs Tocopherol removal was mainly influenced by process temperature and sparging steam Additionally, tocopherol retention seemed to be dependent on the deodorizer design (steam injection geometry and sparging steam distribution) During physical refining, oxidized and polymerized triacylglycerols were not significantly influenced by any of the investigated process parameters Industrially, process conditions are adapted to minimize trans fatty acid formation and maximize tocopherol retention These goals can be achieved in a so-called DUAL TEMP® deodorizer

Soybean based transformer oil and transmission line fluid

Abstract: A biodegradable soybean oil based electrically insulating fluid. The base oil is hydrogenated to produce maximum possible stability of the soybean oil, and can be winterized to remove crystallized fats and improve the pour point of the base oil without the necessity of heating the oil. The base oil can also be combined with an additive package containing materials specifically designed for improved pour point, improved cooling properties, and improved dielectric stability.

Trans-free margarine from highly saturated soybean oil

Abstract: Highly saturated (HS) soybean oil (SBO), which contained 23.3% palmitic acid (C16:0) and 20.0% stearic acid (C18:0), was interesterified at 70°C in preparation for the processing of a trans-free margarine. High-performance liquid chromatography analysis of the triacylglycerides and analysis of the sn-2 fatty acid composition showed no further change after 10 min of interesterification. The interesterified HS SBO had a slip melting point of 34.5°C, compared with 9.5°C in the non-interesterified HS SBO, and increased melting and crystallization temperatures were found using differential scanning calorimetry. Analysis of solid-fat content by nuclear magnetic resonance revealed the presence of only a small amount of solids above 33°C. A 50:50 blend of interesterified HS SBO and SBO with a typical fatty acid composition was used to make the margarine. Compared to commercial soft-tub margarine, the maximal peak force on the texture analyzer of this blended margarine was about 2.3 times greater, the hardness about 2.6 times greater, and adhesiveness about 1.5 times greater. There were small but statistically significant differences (α=0.05) in the sensory properties of spreadability, graininess, and waxiness between the commercial and blended margarines at 4.5°C and, except for graininess, at 11.5°C. These very small differences suggest a potential use for HS SBO in margarine products.

The Chemistry of Metathesized Soybean Oil

Abstract: New materials derived from metathesized soybean oil have been prepared and characterized. Thermal polymerization of metathesized soybean oil in the presence of air results in yellow, brittle gels. These materials display a curious tendency to produce audible popping sounds when exposed to chlorinated organic solvents, such as chloroform or dichloromethane. Complete hydrogenation of metathesized soybean oil has been accomplished in excellent yields utilizing 10% palladium on carbon in dichloromethane. A new, very mild, effective epoxidation procedure for soybean oil, utilizing methyltrioxorhenium (VII) (MTO) and pyridine as the catalyst system and hydrogen peroxide as the oxidant, has been developed. This epoxidation reaction affords excellent yields of epoxidized soybean oil with some control of the degree of epoxidation at very low MTO concentrations (< 0.5 mol%). This reaction is also very effective for the epoxidation of metathesized soybean oil to higher molecular weight epoxidized soybean oil materials.