Showing papers in "Journal of the American Oil Chemists' Society in 1984"
TL;DR: In this paper, the authors showed that the conversion to methyl, ethyl and butyl esters from cottonseed, peanut, soybean and sunflower oils can be done in 1 hr with an alkaline catalyst.
Abstract: Transesterification reaction variables that affect yield and purity of the product esters from cottonseed, peanut, soybean and sunflower oils include molar ratio of alcohol to vegetable oil, type of catalyst (alkaline vs acidic), temperature and degree of refinement of the vegetable oil. With alkaline catalysts (either sodium hydroxide or methoxide), temperatures of 60 C or higher, molar ratios of at least 6 to 1 and with fully refined oils, conversion to methyl, ethyl and butyl esters was essentially complete in 1 hr. At moderate temperatures (32 C), vegetable oils were 99% transesterified in ca. 4 hr with an alkaline catalyst. Transesterification by acid catalysis was much slower than by alkali catalysis. Although the crude oils could be transesterified, ester yields were reduced because of gums and extraneous material present in the crude oils.
1,990 citations
TL;DR: In this article, the major antioxidant activity in the non-hydrolyzed extract was caused by flavonol glycosides, chlorogenic acid (7.1 × 10−4 mol/kg of seed) and caffeic acid (6.6 × 10 −3 m/kg).
Abstract: Chia (Salvia sp) seeds were investigated as a source of natural lipid antioxidants. Methanolic and aqueous extracts of defatted chia seeds possessed potent antioxidant activity. Analysis of 2 batches of chia-seed oils demonstrated marked difference in the fatty acid composition of the oils. In both batches, the oils had high concentrations of polyunsaturated fatty acids. The major antioxidant activity in the nonhydrolyzed extract was caused by flavonol glycosides, chlorogenic acid (7.1 × 10−4 mol/kg of seed) and caffeic acid (6.6 × 10−3 m/kg). Major antioxidants of the hydrolyzed extracts were flavonol aglycones/kaempferol (1.1 × 10−3 m/kg), quercetin (2.0 × 10−4 m/kg) and myricetin (3.1 × 10−3 m/kg); and caffeic acid (1.35 × 10−2 m/kg). Two methods were used to measure antioxidant activities. Both were based on measuring bleaching ofβ-carotene in the coupled oxidation ofβ-carotene and linoleic acid in the presence of added antioxidants.
937 citations
TL;DR: In this paper, an acid-acetalation decomposition procedure was used to evaluate lipid oxidation products as sources of malonaldehyde and its biological effects due to crosslinking.
Abstract: This paper reviews our studies of fatty acid hydroperoxides, their secondary products and mechanisms for their formation in the context of some of their possible biological consequences. The uneven distribution of isomeric hydroperoxides in oxidized linolenate and photosensitized oxidized linoleate is related to the formation of hydroperoxy cyclic peroxides. Interest in the hydroperoxy mono-and bi-cycloendoperoxides from oxidized linolenate stems from their structural relationship to the prostaglandins. However, the biological activity of hydroperoxy cyclic peroxides formed by autoxidation has not yet been reported. Thermal decomposition studies of secondary lipid oxidation products show they are important precursors of volatile compounds. An acid-acetalation decomposition procedure establishes that 5-membered hydroperoxy cyclic peroxides and 1,3-dihydroperoxides are important precursors of malonaldehyde. This approach provides a more specific test than the thiobarbituric acid (TBA) color reaction to evaluate lipid oxidation products as sources of malonaldehyde and its biological effects due to crosslinking. A better understanding is needed of the biological effects of a multitude of lipid oxidation decomposition products other than malonaldehyde.
489 citations
TL;DR: In this paper, the authors compared the performance of soybean oil with diesel fuel and found that the diesel engine performance with soybean ester fuels differed little from engine performance when compared with diesel.
Abstract: The primary problems associated with using straight soybean oil as a fuel in a compression ignition internal combustion engine are caused by high fuel viscosity. Transesterification of soybean oil with an alcohol provides a significant reduction in viscosity, thereby enhancing the physical properties of the renewable fuel to improve engine performance. The ethyl and methyl esters of soybean oil with commercial diesel fuel additives revealed fuel properties that compared very well with diesel fuel, with the exception of gum formation, which manifested itself in problems with the plugging of fuel filters. Engine performance using soybean ester fuels differed little from engine performance with diesel fuel. A slight power loss combined with an increase in fuel consumption were experienced with the esters, primarily because of the lower heating value of the esters than for diesel fuel. Emissions for the 2 fuels were similar, with nitrous oxide emissions higher for the esters. Measurements of engine wear and fuel-injection system tests showed no abnormal characteristics for any of the fuels after the 200-hr tests. Engine deposits were comparable in amount, but slightly different in color and texture, with the methyl ester engine experiencing greater carbon and varnish deposits on the pistons.
341 citations
TL;DR: In this paper, four different vegetable oils, each in at least three different stages of processing, have been characterized according to their physical and chemical properties, their injection and atomization characteristics, and their performance and combustion characteristics in both a directinjection and an indirect-injection diesel engine.
Abstract: Four different vegetable oils, each in at least 3 different stages of processing, have been characterized according to their physical and chemical properties, their injection and atomization characteristics, and their performance and combustion characteristics in both a direct-injection and an indirect-injection diesel engine. The injection and atomization characteristics of the vegetable oils are significantly different than those of petroleum-derived diesel fuels, mainly as the result of their high viscosities. Heating the oils, however, results in spray characteristics more like those observed with diesel fuel. The 2 engine types demonstrated different sensitivities to the composition of the various oils. The combustion characteristics and the durability of the direct-injection engine were affected by the oil composition. The indirect-injection engine, however, was not greatly affected by composition. Two different preliminary specifications have been proposed: a stringent specification including compositional requirements for direct-injection engines, and a less stringent specification for indirect-injection engines. The specifications are discussed in terms of the data and the rationale used in their development. Some precautions concerning the application of the specifications are also presented.
267 citations
TL;DR: In this article, the authors reviewed the chemical and physical changes that occur in frying facts during use and their significance to fat life and to finished product quality, and the more commonly used quality control tests for monitoring these changes are examined as is their applicability to food service institutions and food processors.
Abstract: The chemical and physical changes that occur in frying facts during use and their significance to fat life and to finished product quality are reviewed. The more commonly used quality control tests for monitoring these changes are examined as is their applicability to food service institutions and food processors. The advantages and disadvantages of these tests and possible modifications to improve their ease for on-the-spot testing are discussed. Chemical tests such as free fatty acids (FFA), thiobarbituric acid (TBA) tests and peroxide value (PV) are available to those operations with laboratory facilities, whereas sensory and physical tests, including foam height, color, smoking, viscosity, odor and product flavor, are generally relied on by most food service facilities for on-the-spot assessment. The reliability of these tests, however, depends on the source and type of frying fat, the food being fried, and, in the case of the sensory and physical tests, on the skill and experience of the operator. Studies completed recently in this laboratory found a high correlation between polar compounds or FFA and length of frying time which suggests that either could predict oil abuse accurately. Recent adaptations which could facilitate on-the-spot testing by semi-skilled personnel (including a spot test for FFA and an instrument capable of monitoring the change in dielectric properties of an oil during frying) will be examined. Regardless of the quality control test used, the question remains of specifying reliable cutoff levels which can be related to the health and sensory constraints. This problem is also discussed.
247 citations
TL;DR: When rats are put on high-tannin sorghum diets, their parotid glands undergo hypertrophy and produce a group of unique salivary proteins with extremely high affinity for tannin, which may protect rats against tANNin by binding and inactivating it immediately when it enters the digestive tract.
Abstract: The grain of some varieties of sorghum contains 2% or more condensed tannin; many other varieties contain no tannin at all. Agronomic advantages, e.g., resistance to bird depredation, are associated with high-tannin sorghums, which have relatively low nutritional value for nonruminants. The biological effects of tannin are a result of its propensity for binding proteins; both hydrogen bonding and hydrophobic interactions are involved. Sorghum tannins can bind dietary proteins and reduce their digestibility. Purified digestive enzymes are inhibited by tannin, but significant inhibition in vivo is unlikely. Proteins differ greatly in their affinity for tannin. Those with highest affinity are large, have an open structure, contain no bound carbohydrate and are rich in proline. Sorghum proteins of the alcohol-soluble prolamine fraction associate strongly with tannin, are difficult to remove during tannin purification and are found combined with tannin in the indigestible residue after in vitro digestion with pepsin. On germination, the seed may sacrifice a portion of these proteins to bind the tannin that might otherwise interfere with metabolism by inhibiting seed enzymes. During seed development, tannin molecules are relatively short and do not effectively precipitate proteins; as the seed dries, tannins undergo polymerization to an average of ca. 6 flavan-3-ol units/molecule. The antinutritional effects of sorghum tannins can be eliminated by soaking the grain in dilute aqueous alkali, but not by cooking. When rats are put on high-tannin sorghum diets, their parotid glands undergo hypertrophy and produce a group of unique salivary proteins with extremely high affinity for tannin. These proteins contain over 40% proline and are devoid of sulfur-containing and aromatic amino acids. This metabolic adaption may protect rats against tannin by binding and inactivating it immediately when it enters the digestive tract.
211 citations
TL;DR: In this article, the same advantages that result from extraction of soybeans also apply to the extraction of oil from cottonseed and corn germ, as well as wheat germ and bran, and the oil has a lighter color, a milder odor and less unsaponifiables than that obtained by hexane.
Abstract: Supercritical fluid extraction has recently become a reality in the petroleum, coal and food industries and is rapidly increasing in importance as its advantages become known. Advantages of carbon dioxide as a supercritical fluid include its low toxicity, low cost, lack of flammability, lack of reactivity, wide range of solvent properties at different pressures and temperatures, and improved properties of separated components in certain cases. Disadvantages of such extractions include high capital costs for batch extraction and lack of engineering hardware technology for continuous operation. In the supercritical CO2 extraction of oil from soybeans, equilibrium solubility and high flow rates are readily achieved in a short-path batch reactor. The oil has a lighter color, less iron and ca. 1/10 of the phosphorus contained in hexane-extracted oil. The lower phosphorus content results in lower refining losses. During extraction, some fractionation is observed to take place, with some more polar and/or higher molecular weight compounds having a tendency to increase in the later fractions. In a long cylindrical batch extractor, the flakes perform much like the stationary phase of a chromatographic column. The same advantages that result from extraction of soybeans also apply to the extraction of oil from cottonseed and corn germ. Cottonseed oil obtained by supercritical CO2 extraction has a lower gossypol content and requires less alkali for refining. In the extraction of wheat germ and bran, the oil has a lighter color, a milder odor and less unsaponifiables than that obtained by hexane. Free fatty acid contents were comparable, but tocopherol was higher in the supercritical CO2 extract.
187 citations
TL;DR: In this article, the authors identify a heterogeneous catalyst to selectively produce methyl fatty esters from low erucic rapeseed oil, which is a promising fuel for direct injection diesel engines.
Abstract: Methyl fatty esters derived from vegetable oils are a promising fuel for direct injection diesel engines. This study’s purpose was to identify a heterogeneous catalyst to selectively produce methyl fatty esters from low erucic rapeseed oil. Most experiments were at atmospheric pressure and approximately the corresponding boiling point temperature of the mixture, 60–63 C. However, the catalytic activity of an anion exchange resin was tested at 200 C and 68 atm (1000 psig) and at 91 C and 9.2 atm (135 psig). All samples were analyzed by thin layer chromatography with samples from the elevated temperature and pressure experiments also analyzed by mass spectroscopy. The most promising catalyst examined was CaO·MgO. The activities of the catalysts CaO and ZnO appear to be enhanced with the addition of MgO, therefore the transesterification reaction mechanism may be, in this instance, bifunctional. The anion exchange resin catalyst at 200 C and 68 atm generated substantial amounts of both methyl fatty esters and straight-chain hydrocarbons, even though these reactions did not go to completion. At 91 C and 9.2 atm the cracking also occurred but at a substantially reduced rate, and no transesterification was noted.
187 citations
TL;DR: In this paper, the effect of culture conditions on lipid content and fatty acid composition of chlorella minutissima was investigated, and the results showed that the fat acid composition was affected by culture temperature and supplementation of NaCl.
Abstract: Marine chlorella known to contain high amount of eicosapentaenoic acid (20:5ω3) are a potential natural source of this fatty acid for health foods and pharmaceuticals. The effect of culture conditions on lipid content and fatty acid composition ofChlorella minutissima, therefore, was investigated. Lipid content of cells grown at 25 C was 60% higher than that of the cells grown at 20 C. Fatty acid composition was affected by culture temperature and supplementation of NaCl. Eicosapentaenoic acid 20:5ω3 content was 45% (w/w) in the cells grown at 20 C, whereas that of the cells grown at 25 C was only 20% (w/w). Supplementation with NaCl also increased the percentage of 20:5ω3 acid to the same extent.
176 citations
TL;DR: In this article, the Ziegler process and Oxo synthesis starting from petrochemical feedstocks, and the high-pressure hydrogenation of natural fatty acids and esters are used to manufacture fatty alcohols.
Abstract: The present worldwide capacity of fatty alcohols is ca. 1.0 million metric tons per year. About 60% of this capacity is based on petrochemical feedstocks, 40% on natural fats and oils. Three basic dominating commercial-scale processes are used to manufacture fatty alcohols: the Ziegler process and the Oxo synthesis starting from petrochemical feedstocks, and the high-pressure hydrogenation of natural fatty acids and esters. Basically, the high-pressure hydrogenation can be used with triglycerides, fatty acids or fatty acid esters as feedstock. The direct hydrogenation of fats and oils has not been developed to a commercial-scale process, mainly because it was not possible to prevent decomposition of the valuable byproduct glycerol. Conversion of fatty acids into fatty alcohols by catalytic hydrogenation without preesterification requires corrosion-resistant materials of construction and acid-resistant catalysts. Required reaction temperatures are higher, resulting in a higher hydrocarbon content. The majority of fatty alcohol plants based on natural fats and oils use methyl esters as feedstock. These can be made either by esterification of fatty acids or by-transesterification of triglycerides. For catalytic high-pressure hydrogenation of methyl esters to fatty alcohols, several process options have been developed. The bawic distinguishing feature is the catalyst application either in a fixed bed arrangement or suspended in the methyl ester feed.
TL;DR: Evening primrose (Oenothera spp.) seed contains ca.
Abstract: Evening primrose (Oenothera spp.) seed contains ca. 15% protein, 24% oil, and 43% cellulose plus lignin. The protein is unusually rich in sulphur-containing amino acids and in tryptophan. The component fatty acids of the oil are 65–80% linoleic and 7–14% ofγ-linolenic, but noα-linolenic acid. The 1.5–2% unsaponifiable matter has a composition very similar to that of cottonseed oil. The sterol fraction contains 90%β-sitosterol and the 4-methyl sterol fraction contains 48% citrostadienol;γ-tocopherol dominates its class, with someα- but no other tocopherols.
TL;DR: In this paper, a review of surfactants obtained from fatty acids is presented, which is characterized by their skin tolerance, good biological degradability, low toxicity and low toxicity.
Abstract: This paper reviews selected surfactants obtained from fatty acids. Because of their indispensible properties, some of these surfactants have already been in use for a long time, whereas others, such as sucrose esters or ester sulfonates, are only beginning to be used. However, all these surfactants have in common the fact that they are highly acceptable to the environment, characterized by their skin tolerance, good biological degradability and low toxicity. With consumer awareness becoming more and more apparent, these are noteworthy properties from which we can expect that surfactants prepared from fats will increase in importance in the future.
TL;DR: The first-order kinetics model for tallow, coconut and olive oil hydrolysis was studied in this article, and the results showed that tallow and coconut can be hydrolyzed within 72 hours.
Abstract: The hydrolysis of tallow, coconut oil and olive oil, by lipase fromCandida rugosa, was studied. The reaction approximates a firstorder kinetics model. Its rate is unaffected by temperature in the range of 26–46 C. Olive oil is more rapidly hydrolyzed compared to tallow and coconut oil. Hydrolysis is adversely affected by hydrocarbon solvents and a nonionic surfactant. Since amounts of fatty acids produced are almost directly proportional to the logarithms of reaction time and enzyme concentration, this relationship provides a simple means of determining these parameters for a desired extent of hydrolysis. All three substrates can be hydrolyzed, almost quantitatively, within 72 hr. Lipase fromAspergillus niger performs similarly. The lipase fromRhizopus arrhizus gives a slow hydrolysis rate because of its specificity for the acyl groups attached to the α-hydroxyl groups of glycerol. Esterification of glycerol with fatty acid was studied with the lipase fromC. rugosa andA. niger. All expected five glycerides are formed at an early stage of the reaction. Removal of water and use of excess fatty acid reverse the reaction towards esterification. However, esterification beyond a 70% triglyceride content is slow.
TL;DR: In this article, a novel antioxidant compound has been isolated and identified from the leaves of the Rosmarinus officinalis L. The compound, named rosmaridiphenol, is a diphenolic diterpene.
Abstract: A novel antioxidant compound has been isolated and identified from the leaves of theRosmarinus officinalis L. The compound, named rosmaridiphenol, is a diphenolic diterpene. When tested in lard, the antioxidant activity of this compound was superior to BHA. Structural elucidation of rosmaridiphenol was accomplished by infrared spectroscopy (IR), mass spectroscopy (MS),1H-NMR (nuclear magnetic resonance) and13C-NMR spectroscopy.
TL;DR: In this paper, the authors used scanning electron microscopy to study seed structure before and after extraction with supercritical carbon dioxide (SC-CO2) at a constant temperature (50 C) and pressure (8000 psig).
Abstract: Moisture level and particle size of soybeans, peanuts and cottonseed were correlated with the extraction rate and yield of oil when extracted with supercritical carbon dioxide (SC-CO2) at a constant temperature (50 C) and pressure (8000 psig). The rate of extraction and ultimate oil yields were quite low with cracked soybeans. However, good extraction rates and nearly theoretical oil yields were obtained from ground or thinly flaked (<0.010″) seeds. Moisture levels between 3% and 12% had little effect on extracability. Oil composition was not influenced by either parameter. Scanning electron microscopy was used to study seed structure before and after extraction with SC-CO2. Micrographs of SC-CO2-extracted seeds were similar to hexane-extracted seeds.
TL;DR: In this article, the authors attempted to synthesize carbohydrate esters of fatty acids enzymatically in order to overcome the problems associated with the chemical processes for the synthesis of commercial sucrose esters.
Abstract: The authors attempted to synthesize carbohydrate esters of fatty acids enzymatically in order to overcome the problems associated with the chemical processes for the synthesis of commercial sucrose esters. The enzymes used were lipases from microorganisms belonging toRhyzopus, Enterbacterium, Aspergillus, Pseudomonas, Chromobacterium, Candida, Mucor andPenicillium. Fatty acids (stearic, oleic and linoleic) and carbohydrates (sucrose, glucose, fructose and sorbitol) used for the reaction were obtained from commercial sources. The enzyme reaction was performed by mixing the enzyme and the substrates in the buffer solution and incubating at 40 C; after freeze-drying the mixture, the products were extracted and subjected to thin layer chromatography (TLC) and high performance liquid chromatography (HPLC). It was observed by TLC and HPLC that carbohydrate esters of fatty acid were produced by the enzyme reaction, and their structures were confirmed by infra red (IR) and nuclear magnetic resonance (NMR) spectrometries. The lipase fromCandida cylindracea was the most enzyme active on the synthesis of carbohydrate esters. The optimum conditions for its activity were as follows: molar ratio of carbohydrate to fatty acid: 0.05mol/l : 0.2mol/l; amount of lipase: 4g/l; pH of the reaction mixture: 5.4 in phosphate buffer; reaction period: 72 hr.
TL;DR: In this paper, the basic equations which govern the oil extraction from a bed of seeds were derived from first principles and solved by standard numerical techniques using experimentally determined parameters for the concentration of oil in the solvent in equilibrium with seeds having a known oil content.
Abstract: The extraction of oil from canola seeds using supercritical carbon dioxide was investigated. The basic equations which govern the oil extraction from a bed of seeds were derived from first principles. The equations can be solved by standard numerical techniques using experimentally determined parameters for the concentration of oil in the solvent in equilibrium with seeds having a known oil content. Preliminary extraction rate data and equilibrium data are given for crushed canola seed during extraction using supercritical carbon dioxide at select temperatures and pressures. The research is directed at obtaining the basic information required for the design of continuous countercurrent extractors.
TL;DR: In this article, the authors used thin layer (TLC) and paper chromatography of the methanolic peanut extracts yielded six fluorescent bands of which one exhibited potent antioxidant activity and further separation by TLC showed this band to be a complex mixture of three components.
Abstract: Hot methanol extracts of Spanish peanuts were found to possess antioxidant activity. Thin layer (TLC) and paper chromatography of the methanolic peanut extracts yielded 6 fluorescent bands of which one exhibited potent antioxidant activity. Further separation by TLC showed this band to be a complex mixture of 3 components that were tested for antioxidant activity. One component demonstrated all of the antioxidant activity associated with the parent band. Analysis of this antioxidant by paper chromatography and TLC, chromatographic spray reagents and spectral analysis demonstrated that the compound was dihydroquercetin.
TL;DR: The Moringa peregrina kernel contains 1.8% moisture, 54.3% oil, 22.1% protein, 3.6% fiber and 2.5% ash as discussed by the authors.
Abstract: TheMoringa peregrina kernel contains 1.8% moisture, 54.3% oil, 22.1% protein, 3.6% fiber, 15.3% carbohydrate and 2.5% ash. The composition and characteristics of the extracted oil were determined. Gas liquid chromatography of methyl esters of the fatty acids shows the presence of 14.7% saturated fatty acids and 84.7% unsaturated fatty acids. The fatty acid composition is as follows: palmitic 9.3%, palmitoleic 2.4%, stearic 3.5%, oleic 78.0%, linoleic 0.6%, linolenic 1.6%, arachidic 1.8% and behenic 2.6%.
TL;DR: Enzymes have been shown to have potential in large-scale processing of lipid material, particularly in the areas of fat splitting, synthesis by reversal of hydrolysis and interesterification.
Abstract: Enzymes have advantages for industrial processing. These are: 1) specificity which permits control of the products produced and also can increase yield by reducing the amount of side products; 2) mild conditions which can decrease the cost in terms of energy and capital equipment as well as reducing the amount of unwanted side products by reducing the rate at which they are formed by virtue of the lower temperature, and 3) lowered waste treatment costs. Enzymes function well in an industrial setting, since enzymatic modification of carbohydrate or protein is an integral part of the process in a number of major industries. Enzymatic modification of lipids currently is being used commercially in the area of flavor development as well as degreasing for leather processing. Recent investigations have shown that enzymes have potential in large-scale processing of lipid material, particularly in the areas of fat splitting, synthesis by reversal of hydrolysis and interesterification.
TL;DR: A membrane bioreactor was developed for continuous synthesis of glycerides by lipase to overcome the drawbacks associated with the usual operation in an emulsion system, yielding a conversion above 70% when 1% CaCl2 was added in the glycerol solution.
Abstract: A membrane bioreactor was developed for continuous synthesis of glycerides by lipase to overcome the drawbacks associated with the usual operation in an emulsion system. One unit (total area: 726 cm2) of flat, plate-type dialyzer was used as the membrane bioreactor at 40 C. The glycerol solution, containing bacterial lipase and water, was supplied continuously to 1 side of a sheet of microporous polypropylene membrane (strongly hydrophobic) and the effluent was recycled, while undiluted liquid fatty acid (oleic or linoleic) was fed continuously to the opposite side of the membrane and came in contact with a glycerol-water-lipase solution to cause the reaction. The product, glycerides, was obtained at the outlet, in a pure state, with no other phase. Highest conversion (ca. 90%) was obtained when the water content of the glycerol solution was 3–4%. As the accumulation of water produced by the reaction lowered the conversion, molecular sieves in a column that the glycerol solution passed through were used for optimal water content. The reaction could be continued at least for 1 month, yielding a conversion above 70% when 1% CaCl2 was added in the glycerol solution. The main component of glycerides formed was almost equimolar amounts of mono-and diglycerides.
TL;DR: In this article, the geometrical isomers of linolenic acid were identified from a rapeseed oil heated at 240 C for 10 hours by a combination of thin layer chromatography (TLC) of the methoxy bromomercuric adducts of the total methyl esters and AgNO3-TLC.
Abstract: Heat treatment of rapeseed (primor) and soybean oils resulted in the geometrical isomerization of linolenic acid. The geometrical isomers were isolated from a rapeseed oil heated at 240 C for 10 hr by a combination of thin layer chromatography (TLC) of the methoxy bromomercuric adducts of the total methyl esters and AgNO3-TLC. Three major isomers were identified after hydrazine reduction followed by ozonolysis in BF3-MeOH as 18:3Δ9c, 12c, 15t, 18:3Δ9t, 12c, 15c and 18:3Δ9t, 12c, 15t. These were accompanied by minor amounts of 18:3Δ9c, 12t, 15c, 18:3Δ9c, 12t, 15t and 18:3Δ9t, 12t, 15c. The 18:3 isomers were detected in both soybean and rapeseed oil heated at 240 C for 10 hr. At this temperature, the increase in time of the heat treatment from 10 to 40 hr resulted in a relative increase of the di-trans and in a decrease of the mono-trans isomers. Only minor quantities of these isomers were detected in the oils heated at 200 C for 10 hr. At this temperature, the increase in time of the heat treatment resulted in an increase of both the mono- and di-trans isomers.
TL;DR: The safety and efficacy of fatty acid esters as potential germicides offer new and expanded roles for oleochemicals.
Abstract: The author reviews his research, since 1966, for the ideal germicide. The relationship between structure of fatty acids, their corresponding esters, and antimicrobial activity is presented. Saturated fatty acids have their highest activity when the chain length is twelve carbons (C12) long; monounsaturated fatty acids reach their peak with palmitoleic acid (C16∶1); the most active polyunsaturated fatty acid is linoleic.Trans isomers are not active against microorganisms. The esterification of fatty acids to monohydric alcohols leads to inactive derivatives, whereas esterification to polyhydric alcohols increases biological activity. Examples of glycerol and sucrose esters are reviewed. In general, the lauroyl derivatives are the most active. A few examples of esters as active pharmacological agents against organisms causing bovine mastitis are presented as well as the use of monolaurin (Lauricidin®) as cosmetic and food preservatives. The safety and efficacy of fatty acid esters as potential germicides offer new and expanded roles for oleochemicals.
TL;DR: There was a strong inverse relationship between oleic and linoleic acids among seeds from M2 plants, which supports the hypothesis of sequential desaturation as the method of formation of unsaturated fatty acids in soybean oil.
Abstract: Soybean (Glycine max [L.] Merr. cv. Century) seeds were treated with ethylmethanesulfonate (EMS) and the M2 progeny were evaluated for fatty acid composition of the oil. Treatment with EMS significantly increased the variability in content of each of the fatty acids in comparison with those of the Century control. There was a strong inverse relationship between oleic and linoleic acids among seeds from M2 plants. This supports the hypothesis of sequential desaturation as the method of formation of unsaturated fatty acids in soybean oil. A genetically stable mutant with 3.4% linolenic acid was identified that was similar to the cultivar Century in days to maturity, plant height and resistance to lodging.
TL;DR: In this article, a nonionic sunflower oil-aqueous ethanol microemulsion was formulated, characterized and evaluated as a fuel in a direct injection, turbocharged, intercooled, 4-cylinder Allis-Chalmers diesel engine during a 200 hr EMA cycle laboratory screening endurance test.
Abstract: A nonionic sunflower oil-aqueous ethanol microemulsion was formulated, characterized and evaluated as a fuel in a direct injection, turbocharged, intercooled, 4-cylinder Allis-Chalmers diesel engine during a 200 hr EMA cycle laboratory screening endurance test. Differences in engine operation between a baseline Phillips 2D reference fuel and the experimental fuel were observed. The major problem experienced while operating with the microemulsion was an incomplete combustion process at low-load engine operation. Significant lubricating oil dilution was observed initially, followed by an abnormal increase in the viscosity of the lubricative oil. Heavier carbon residue on the piston lands, in the piston ring grooves and in the intake ports was noted. In addition, premature injection-nozzle deterioration (sticking of the needle) was experienced. At present, the sunflower oil-aqueous ethanol microemulsion studied cannot be recommended for long-term use in a direct-injection diesel engine, but further modifications in formulation may produce acceptable sunflower oil microemulsions as alternative diesel fuels.
TL;DR: This paper analyzed cyclic fatty acid monomers in commercial frying oils, obtained in this country and in the Middle East, from street vendors frying vegetable patties (known as “fallafel”) in open-air stands.
Abstract: Cyclic fatty acid monomers were analyzed by gas chromatography in commercial frying oils, obtained in this country and in the Middle East. Samples were obtained from food outlets in California and Illinois after varying periods of usage. The samples from Egypt and Israel were collected from street vendors frying vegetable patties (known as “fallafel”) in open-air stands. The United States samples ranged from 0.1 to 0.5% cyclic monomers, and from 1 to 8% polar +noneluted thermal oxidation materials. The Middle Eastern samples showed significantly more heat abuse, with values for cyclic monomers from 0.2 to 0.7% and polar materials ranging from 2 to 22%.
TL;DR: In this paper, a screening test of fungal metabolites was performed for developing new types of antioxidants and synergists for tocopherol (Toc), and it was found that flavoglaucin is an excellent antioxidant and synergist.
Abstract: Screening tests of fungal metabolites were performed for developing new types of antioxidants and synergists for tocopherol (Toc). Flavoglaucin has been found to be an excellent antioxidant and synergist. It is a phenolic compound isolated from mycelial mats ofEurotium chevalieri. Under autoxidation conditions, flavoglaucin remarkably synergized with Toc and stabilized many edible oils and fats. After the addition of flavoglaucin (0.05 %) the vegetable oils retained their original stabilities even after thermal treatment at 180 C for 25 hr. During the oxidation of lard containing Toc (0.04%) under the simulated deep-fat frying conditions, the addition of flavoglaucin didn’t retard the oxidative decomposition of Toc. However, the stability of lard always was higher in the presence of flavoglaucin than in its absence. Flavoglaucin is not mutagenic to Salmonella typhimurium TA 100 and TA 98.
TL;DR: From the hydrolysis data, an empirical relationship was developed that shows that the percentage of free fatty acid formed is almost a linear function of the logarithm of reaction time and the logarshipm of enzyme concentration.
Abstract: Commercial dry lipase fromCandida rugosa (formerlyC. cylindracea) was used to catalyze hydrolysis of tallow, coconut oil and olive oil at 26–40 C. A methodology was developed to yield results reproducible within ±10% and to achieve essentially complete hydrolysis. From the hydrolysis data, an empirical relationship was developed that shows that the percentage of free fatty acid formed is almost a linear function of the logarithm of reaction time and the logarithm of enzyme concentration. A 95–98% hydrolysis of the 3 substrates was achieved experimentally in 72 hr, requiring 15 units lipase per milliequivalent (U/meq) of coconut oil or tallow and 6 U/meq of olive oil. The kinetics of lipolysis were determined for all 3 substrates and were found to approximate first order. Lipolysis rate was higher for olive oil than for tallow and coconut oil; no significant differences were observed between the latter 2 substrates. No statistically significant change in overall reaction rate was found when the hydrolysis was run at 26 C, 36 C or 46 C. Although the literature cites calcium or sodium ions and albumin as beneficial adjuvants to enzymatic lipolysis, these additives appeared to have no significant beneficial effect on the reaction. On the other hand, hydrocarbon solvents and nonionic surfactants showed an adverse effect.
TL;DR: In this article, the first allylic hydroperoxides were identified and a better understanding of the routes leading to the first formed allylic hydroxides and an improved appreciation of the structure of further oxidation products were presented.
Abstract: Oxygen reacts readily with unsaturated fatty acids so that every time these compounds are handled there is a danger they will become contaminated with oxidation products. The products formed first are allylic hydroperoxides which are labile molecules that change rapidly to other compounds, some of which are highly flavorous. Sometimes these changes are desirable and may be promoted: frequently they are not and have to be inhibited. Instrumental procedures recently introduced—especially separation by high performance liquid chromatography and identification by1H and13C nuclear magnetic resonance spectroscopy—have led to a renewed interest in this subject. For the nonenzymic processes of autoxidation and photooxygenation we now have a better understanding of the routes leading to the first-formed allylic hydroperoxides and an improved appreciation of the structure of further oxidation products including dihydroperoxides and hydroperoxides which also contain one or more cyclic peroxide units. Direct chemical routes to several of these compounds have also been developed. Oxidation of linoleic acid by plant-derived lipoxygenases gives diene hydroperoxides similar to those produced by autoxidation, except that the former are optically active and the latter racemic. Enzymic oxidation of arachidonic acid and certain related C20 acids in animal systems produces a wide variety of prostaglandins, physiological properties. These compounds have been described as “tomorrow’s drugs”.