Cardiopathogenicity of soybean oil and tower rapessed oil triglycerides when fed to male rats

The triglycerides of soybean oil were purified by molecular distillation and those of Tower rapeseed oil by molecular distillation and adsorption chromatography. The original oils and the purified triglycerides were incorporated in semisynthetic diets at 20% by weight and fed for 16 weeks to weanling male Sprague-Dawley rats to compare the nutritional and pathological effects of the oils and their triglyceride fractions on rats. The study was carried out at two independent laboratories. No significant differences were observed between the results of the two establishments. The incidence of myocardial lesions was significantly higher in rats fed Tower rapeseed oil than in those fed soybean oil. Purification of the triglycerides by molecular distillation and adsorption chromatography appeared to have no major effect on the incidence of myocardial lesions. This supports our previous findings that the cardiopathogenicity of the test oils to rats resides in the triglycerides of these oils. Contribution No. 832 from Animal Research Institute and No. I-78 from Engineering and Statistical Research Institute.     

Brassica campestris var. Span: I. Fractionation of Rapeseed oil by molecular distillation and adsorption chromatography

Procedures for the large scale isolation of pure triglycerides and fractions rich in nontriglyceride components from Span rapeseed oil are described. Fractionation ofBrassica campestris var. Span rapeseed oil by molecular distillation yielded 4 triglyceride fractions, all of which contained traces of sterol esters. An additional triglyceride fraction rich in free and esterified sterols and other volatile components was obtained from the oil. Separation by adsorption chromatography of Span rapeseed oil yielded three fractions: A) a pure triglyceride fraction; B) a triglyceride fraction rich in sterol esters; and C) another fraction containing free sterols and other polar components. Contribution no. 559 Animal Research Institute.     

Changes in liver lipid composition of male rats fed rapeseed oil diets

Studies are reported on the effect of feeding diets containing rapessed oils differing in their erucic acid content to male weanling rats for 16 weeks. Rapeseed oil high in erucic acid depressed growth. Total lipids, lipid phosphorous and cholesterol, in the livers were not significantly different between the experimental groups. The fatty acid composition of the total liver lipids, the neutral lipids, phosphatidylethanolamine and phosphatidylcholine are documented. Erucic and eicosenoic acids were found in all lipid classes at the same relative concentration; the amount being incorporated was proportional to that found in the dietary oil. The positional analysis of phosphatidylethanolamine and phosphatidylcholine are presented. Erucic acid was incorporated preferentially at position two of these phospholipids, whereas, twice the level of eicosenoic acid was found at position one, compared to that which occurred at the two position. This article represents part of an extensive experiment carried out by Agriculture Canada to investigate the nutritional value of rapeseed oils (see ref. 15). Contribution No. 497 from the Animal Research Institute.     

Myocardial lipids and nucleotides of rats fed olive oil or rapeseed oil

After 1 week, the level of myocardial fatty acids was 4 times greater in young rats fed high erucic rapessed oil than in those fed olive oil. The proportion of erucic acid was 5.6% in the mitochondrial fraction, 15.1% in the microsomal fraction, and 34.8% in the floating fat fraction. This incorporation of erucic acid into triglycerides of the floating fat was evidence of esterification. The changes in the mitochondrial lipids did not alter the content of adenine nucleotides of the myocardium nor its apparent capacity to oxidize substrates.     

Changes in fatty acid composition of cardiac mitochondrial phospholipids in rats fed rapeseed oil

Male Wistar rats were fed rapeseed oil containing high or low levels or erucic acid for 20 weeks, and changes in the fatty acid composition of cardiac mitochondrial phospholipids were studied. Treatment with rapeseed oil containing 46.2% erucic acid showed incorporation of 22∶1 (5.6%) into isolated cardiolipin from heart mitochondria. After high or low (3.7%) erucic rapeseed oil feeding, linoleic acid was slightly incorporated into cardiolipin. Moreover, both of these rapeseed oils induced a significant increase of linoleate-arachidonate ratio in phosphatidylethanolamine and phosphatidylcholine. This ratio was also significantly increased in fatty acids esterified to the β-position of these phospholipids. On the basis of such results, we have to consider the role of linolenic acid which is present at a high level in the different rapeseed oils used, as a possible inhibitor of heart microsomal enzymes involved in linoleate arachidonate conversion. Such alterations might account for mitochondrial fragility and myocardial lesions obtained in long term rapeseed oil feeding experiments. ERA-CNRS n^o 070497     

The effect of clofibrate on heart and plasma lipids in rats fed a diet containing rapeseed oil

The effect of clofibrate on heart and plasma lipids in rats fed a diet containing 30% of the calories as peanut oil (PO) or rapeseed oil (RSO) (42.7% erucic acid and 0.5% eicosenoic acid) was studied. A decrease of erucic acid content to one-third and concomitant increase in the content of 18∶1, 16∶1 and 16∶0 fatty acids in plasma triacylglycerols were observed after administration of clofibrate to rats fed the RSO-diet. It is suggested that these changes reflect the increased capacity of the liver to chainshorten very long chain length fatty acids. The extent of lipidosis in the heart of rats fed the RSO-diet was decreased by 50% by clofibrate. However, the concentration of erucic acid in heart triacylglycerols decreased much less (30%) than the concentration of all other fatty acids (50–65%). It is concluded that the clofibrate administration increased the oxidative capacity of the heart mitochondria and that the heart cell does not have an efficient system to handle very long chain length monounsaturated fatty acids as does the liver.     

Feedstock recycling from plastics and thermosets fractions of used computers. II. Pyrolysis oil upgrading

Liquid products obtained from pyrolysis of plastics and thermosets fractions (keyboard, casings and printed circuits board and their mixture) of used computers were upgraded by thermal and catalytic hydrogenation. The effect of thermal hydrogenation was improved by using catalysts such as commercial hydrogenation DHC-8 catalyst and metal loaded activated carbon. The upgraded degradation products were separated in three fractions (residue, liquids and gases) and characterized by suitable methods such as gas chromatography (GC-MSD, GC-AED), infrared (FT-IR) and ¹H-NMR spectroscopy, elemental analysis, etc. Using of catalyst mainly affected the product distribution of upgrading process. Liquids having high amount of aromatics were obtained by upgrading. Most of hazardous toxic compounds in liquids were eliminated after hydrogenation (e.g., halogens were removed mainly by converting them into gaseous hydrogen chloride and bromide). It has been established that the hydrogenation led to elimination of the most of hazardous toxic compounds, mainly those containing bromine.     

Kinetics of the hydrogenation of rapeseed oil: II. Rate equations of chemical reactions

The kinetics of rapeseed oil hydrogenation was studied at 140–220 C and at 0.3–10 atm hydrogen pressure in a laboratory reactor in the presence of 0.05% nickel catalyst. A mathematical model was fitted to the experimental data, and temperature and pressure dependence of the different reaction steps was discussed on the basis of the model. The adequacy of the model was tested by means of a residual analysis.     

Synthesis of cholesterol and total lipid by male and female rats fed beef tallow or corn oil

Male and female weanling rats were fed diets containing 2 or 42% of calories as corn oil or 40% as beef tallow plus 2% as corn oil until they were 12 or 18 weeks of age. Incorporation of C¹⁴-acetate into lipids of serum and liver and concentration of lipids in serum, liver, and carcass at the end of these periods were determined. Net synthesis of noncholesterol lipid was repressed by changing the diet from 2% to 42% of calories from either dietary fat in both sexes and at both ages. Cholesterol net synthesis was enhanced 29-fold in males and 22-fold in females fed 42% corn oil compared to 2% corn oil to the age of 12 weeks. It was enhanced only 2.6-fold for males and 3.4-fold for females by 40% beef tallow plus 2% corn oil. At 18 weeks of age cholesterol synthesis in males fed 42% corn oil was 7.3 and in females 9.1 times the value for those fed 2% corn oil. At this age the values for rats fed 40% beef tallow plus 2% corn oil were 1.2 and 3.7 times those for 2% corn oil fed rats of the respective sexes.     

Lipoprotein lipase in rats fed fish oil: Apparent relationship to plasma insulin levels

To investigate the role of lipoprotein lipase (LPL) and hepatic lipase in the triacylglycerol lowering effects of fish oil, rats were fed lard (L), corn oil (CO) or menhaden oil (MO) as the primary fat source in otherwise identical diets. After 2 weeks, soleus muscle LPL differed between groups (MO>CO>L). Hepatic lipase did not differ between CO- and MO-fed rats but was elevated in L-fed rats. Adipose LPL did not differ between diet groups. Total epididymal fat weight was reduced in MO-fed rats. There was a significant positive correlation between adipose tissue weight and plasma free fatty acids. MO-fed rats had lower plasma insulin levels. Insulin was directly correlated with plasma triacylglycerol and glucose, consistent with a hyperinsulinemic, insulin-resistant state in CO-and L-fed rats, and a protective effect with MO feeding. In addition, insulin was directly correlated with adipose LPL. A negative relationship between soleus muscle LPL and insulin approached significance. Soleus muscle LPL was significantly inversely correlated with triacylglycerol. The data indicate that increased skeletal muscle LPL, in response to MO or a MO-induced decrease in insulin, may contribute to the triacylglycerol-lowering effects of fish oil. Decreased fat weight and adipose LPL and increased soleus muscle LPL and decreased plasma triacylglycerol suggest a shift from fat deposition to oxidation with MO feeding. The lack of response of hepatic lipase to MO feeding suggests that this enzyme does not contribute to the fish oil-stimulated lowering of plasma triacyglycerolvia hepatic reuptake of very low density lipoproteins or other triacylglycerol-rich lipoproteins.     

Fatty acid selectivity of lipases: Erucic acid from rapeseed oil

The fatty acid selectivity of several commercial lipases was evaluated in the hydrolysis of high-erucic acid rapeseed oil (HEARO). The lipase ofPseudomonas cepacia catalyzed virtually complete hydrolysis of the oil (94–97%), while that ofGeotrichum candidum discriminated strongly against erucic acid, especially in esterification. A two-step process is suggested for obtaining a highly enriched erucic acid in which theG. candidum lipase is employed to selectively esterify the fatty acid residues of unsaturated C-18, and shorter chain acids, from a mixture of HEARO fatty acids obtained from total hydrolysis of the oil withP. cepacia lipase.     

Levels of polyunsaturated fatty acids in tissues from zinc-deficient rats fed a linseed oil diet

The effect of zinc deficiency on the levels of n−6 and n−3 polyunsaturated fatty acids (PUFA) in lipids from tissues of rats fed a diet containing linseed oil was investigated. Rats were fed either a control diet (25 mg Zn/kg) or a zinc-deficient diet (0.8 mg Zn/kg) for 10 d. To avoid energy and nutrient deficiency, 11.6 g of diet per day was administered by gastric tube. At the end of the experiment, rats fed the zinc-deficient diet had drastically reduced plasma zinc concentration and alkaline phosphatase activity consistent with severe zinc deficiency in these rats. Zinc-deficient rats had higher levels of n−3 PUFA, in particular eicosapentaenoic acid (EPA), and lower levels of n−6 PUFA, in particular linoleic acid, in liver and plasma phosphatidylcholine (PC) and in erythrocyte membrane total lipids than did control rats. By contrast, the levels of n−3 PUFA in PC from testes and heart, and in phosphatidylethanolamine (PE) from liver, testes and heart, were only slightly different between zinc-deficient and control rats. The study suggests that desaturation of α-linolenic acid is not inhibited by zinc deficiency, and that in zinc-deficient rats, n−3 PUFA preferentially incorporated into phospholipids at the expense of n−6 PUFA, especially EPA into PC. The study also shows that the effect of zinc deficiency on PUFA levels is different for PC and PE in rat tissues.     

Cocoa butter-like fats from fractionated cottonseed oil: II. Properties

Previously it was reported that the stearine obtained as a byproduct in the solvent winterization of cottonseed oil is a good starting material for the preparation of cocoa butter-like fats by way of hydrogenation and fractionation. The composition, physical properties, and compatability with cocoa butter have been determined for some of these fats. While the products contained triglyceride species other than those in cocoa butter, the major components were similar in that they were 2-oleodisaturated glycerides. The cocoa butter-like fats underwent slow polymorphic transformations, but made confectionery coatings remarkably resistant to bloom. Cooling curves resembled those of cocoa butter. Hardness was related to melting point; those fats melting below 35 C were softer than cocoa butter at room temperature, but fats melting above 35 C could be made to resemble cocoa butter in hardness. Adding cocoa butter to the cocoa butter-like fats had little effect on the softening point. X-Ray diffraction studies of 1:1 mixtures gave no evidence of mixed crystal formation; the long spacings resembled those of mechanical mixtures. In some other mixtures, certain short spacings became more pronounced. ARS, USDA.     

Optimized Extraction and High Selective Purification of Flavonoids and Intermediate Polar Nitrogen-Containing Constituents from Brassica campestris L. Pollen

For the first time, an efficient purification process of flavonoids and intermediate polar nitrogen-containing constituents from Brassica campestris L. pollen with the help of an improved polystyrene based matrix, LS305 was developed. Three methods (Ultra Fast Liquid Chromatographic with Ultraviolet/Diode Array Detector, spectrophotometric, and automatic Kjeldahl) have been applied for the determination and quantification of flavonoids and nitrogen. With the help of the purification process, the flavonoids content was increased from ～16% to ～45% (w/w). ～6% (w/w) nitrogen originated from intermediate polar nitrogen-containing compounds was retained. These results would contribute to improve industrial processes.     

Analysis of low erucic acid turnip rapeseed oil (Brassica campestris) by negative ion chemical ionization tandem mass spectrometry. A method giving information on the fatty acid composition in positionssn-2 andsn-1/3 of triacylglycerols

A tandem mass spectrometric method is described for the rapid analysis of fatty acid combinations in mixtures of triacylglycerols. Triacylglycerols were introduced into a triple quadrupole mass spectrometervia a direct exposure probe and deprotonated using ammonia negative ion chemical ionization. Collisionally activated spectra were obtained and the resulting fragments used to identify the fatty acid constituents, and the fatty acids preferentially located at thesn-2 position of the triacylglycerols. Fourteen major molecular weight species of purified triacylglycerols of a supercritical fluid extract of low erucic acid turnip rapeseed oil (Brassica campestris) were analyzed. The five major combinations of fatty acids comprised two thrids of the total triacylglycerols and contained oleic, linoleic and α-linolenic acids with linoleic acid favoring thesn-2 position.     

Biodiesel from rapeseed oil,methanol and KOH. 3. Analysis of composition of actual reaction mixture

Detailed analysis is described of the samples taken after suitable reaction times from the actual reaction mixture during the production of biodiesel fuel using methanolysis of rapeseed oil catalyzed by KOH. Three methods for stoppage of reaction (neutralisation of catalyst, dilution by two suitable solvents) in the sample are used. The contents of mono‐, di‐ and triacylglycerols, methylesters of fatty acids (biodiesel) and potassium salts of fatty acids of rapeseed oil, glycerol (by HPLC method), basicity (by potentiometric titration) and water (by GC and Karl‐Fischer method) in the samples are determined. An example of these determinations is described.     

Polymerizable monomers from castor oil: II. Syntheses of some divinyl monomers

Ten divinyl monomers have been synthesized, based on commonly available products derived from castor oil, in 50–100 g lots of high purity. These were characterized by infrared spectroscopy and their purity was checked by chromatographic methods. Boiling points, refractive indices and iodine values of the products are reported. Thin layer chromatography of divinyl monomers based on decanedioic acid has also been studied.     

New process for the production of better quality rapeseed oil and meal: II. Detoxification and dehulling of rapeseeds — feasibility study

Feasibility studies have shown that a white, bland, defatted, thioglucoside-free flour can be prepared from rapeseed. The thioglucosides, the precursors of toxic principles, present in rapeseeds are removed by aqueous extraction. The key operations, boiling of the seed followed by wet-grinding and aqueous extraction, help in the removal of seed coat from the rapeseed. Although aqueous extraction results in the loss of solids, the quality of the end products is good and may offset the loss. Issued as No. 108 of the Food Research Institute.