Showing papers in "Journal of the American Oil Chemists' Society in 1955"
TL;DR: In this article, it was found that during the hydrogenation of octadecenoic acids, migration of the double bonds takes place equally in each direction, and the positional isomers that are formed are composed of the 1∶2 equilibrium mixture ofcis andtrans.
Abstract: It was found that during the hydrogenation of octadecenoic acids, migration of the double bonds takes place equally in each direction. The positional isomers that are formed are composed of the 1∶2 equilibrium mixture ofcis andtrans. A partial hydrogenation-dehydrogenation theory may be applied to explain the simultaneous formation of both positional and geometrical isomers.
116 citations
TL;DR: In this paper, a method for the determination of oil on long series of oilseed is presented, which is a gravimetric method which reduces the hand labor to a minimum, and the difference between averages for the new method and averages of extraction analyses made with continuous extractors did not exceed 0.28% of oil.
Abstract: A new method for the determination of oil on long series of oilseed is presented. It is a gravimetric method which reduces the hand labor to a minimum. Testing this method on a series of pure samples of oilseed, which were analyzed for five days with two analyses on each sample every day, the standard deviation for a single analysis lay within 0.30% and for the average of two duplicates within 0.27% of oil. The difference between averages for the new method and averages of extraction analyses made with continuous extractors did not exceed 0.28% of oil.
81 citations
72 citations
TL;DR: Physical characterizations of the ethyl esters of the naturally occurring C6−C18 saturated fat acids and the ethanoate esters corresponding to the above acids have been made in this paper, where refractive indices at 20°, 25°, 30°, 35° and 40°C, densities and viscosities at 35°, 50°, 65°, 80°, and 95° C, and boiling points at several pressures.
Abstract: Physical characterizations of (1) the ethyl esters of the naturally occurring C6−C18 saturated fat acids and (2) the ethanoate esters of the saturated alcohols corresponding to the above acids have been made. They are a) refractive indices at 20°, 25°, 30°, 35°, and 40°C., b) densities and viscosities at 35°, 50°, 65°, 80°, and 95° C., and c) boiling points at several pressures. The physical characteristics exhibited by the two series of esters are quite similar. However the actual values obtained for the ethanoate esters are slightly higher than those obtained for the corresponding ethyl esters.
67 citations
67 citations
TL;DR: In this paper, a method is described by which unsaturated fatty acid esters can be separated and identified by reversed-phase paper chromatography, based upon the formation of the mercuric acetate addition compounds of the esters and the detection of the compounds on the chromatograms, using the sensitive color reaction with diphenyl carbazone.
Abstract: A method is described by which unsaturated fatty acid esters can be separated and identified by reversed-phase paper chromatography. The procedure is based upon the formation of the mercuric acetate addition compounds of the esters and the detection of the compounds on the chromatograms, using the sensitive color reaction with diphenylcarbazone. The application of this technique to the analysis of the component unsaturated acids of natural fats has been examined, and tetradecenoic acid in olive oil and hexadecenoic acid in linseed oil both formerly unidentified have been detected as the minor component acids by means of the method. The preliminary investigation on the absorption spectra of diphenylcarbazone complexes derived from the addition compounds has been made to bring the method into quantitative use.
59 citations
TL;DR: In this article, a steam-distillation of dry whole milk was found to be an effective means of separating the products of fat oxidation preparatory to reacting them with 2-thiobarbituric acid (TBA).
Abstract: Steam-distillation of dry whole milk was found to be an effective means of separating the products of fat oxidation preparatory to reacting them with 2-thiobarbituric acid (TBA). The milk powder samples were reconstituted and acidified prior to steam distillation. A fraction of the distillate was reacted with the reagent to produce the red-colored product, which was then estimated spectrophotometrically at 530 mμ. Factors which influence the sensitivity and reliability of the method were investigated. The method is rapid and reproducible, and the test solutions are free of turbidity. The reaction is a measure of the oxidation of dry whole milk, and when it was applied to samples from storage, the results had validity in terms of flavor.
56 citations
TL;DR: The thiobarbituric acid (TBA) reaction for fatty acid oxidation has been compared with Lundberg and Chipault's method for peroxides, the Kreis test for aldehydes, and with the degree of conjugation, using fatty acid esters exposed to ultraviolet light for various periods.
Abstract: The thiobarbituric acid (TBA) reaction for fatty acid oxidation has been compared with Lundberg and Chipault's method for peroxides, the Kreis test for aldehydes, and with the degree of conjugation, using fatty acid esters exposed to ultraviolet light for various periods. The TBA test paralleled the other methods for methyl linolenate and methyl linoleate but was essentially negative for methyl oleate oxidation.
56 citations
TL;DR: The sesamol content of all the oils subjected to the accelerated ageing procedure increased, but the increase was greatest in the rancid oils, and the ultraviolet spectrum of the oil was much altered.
Abstract: The effect of strain and location grown on the sesmin, sesamolin, and sesamol content of oils from sesame seed chosen to represent a wide variety of genetic material is reported. Only differences in sesamin content due to strain were significant.
53 citations
TL;DR: In this paper, the solubilities of cottonseed, peanut, sesame, and soybean oils in aqueous alcoholic solutions at various temperatures were determined directly and the curves for the four oils were presented.
Abstract: Solubilities of cottonseed, peanut, sesame, and soybean oils in aqueous alcoholic solutions at various temperatures were determined directly. Solubility curves for the four oils in aqueous alcoholic solutions are presented.
52 citations
TL;DR: In this article, the infrared spectra from 2 to 12 microns of chloroform solutions of several glycerides have been measured and studied with a view to possible analytical applications.
Abstract: The infrared spectra from 2 to 12 microns of chloroform ( solutions of several glycerides have been measured and studied with a view to possible analytical applications. These spectra are presented, and conclusions which can be obtained from their examination are reported in this paper.
TL;DR: In this article, a study of binary systems involving SSS with PPP, PSP, LLL, SOS, or OOO, also SOS with OOO shows that agreement of liquidus position with the Hildebrand solubility law is possible for these triglycerides.
Abstract: A study of binary systems involving SSS with PPP, PSP, LLL, SOS, or OOO, also SOS with OOO shows, for these triglycerides, agreement of liquidus position with the Hildebrand solubility law. Solid solution is essentially absent in LLL-SSS and OOO-SSS and OOO-SOS but definitely occurs with PPP-SSS, PSP-SOS, and SOS-SSS, where it is clearly shown by x-ray and dilatometric evidence. Solid solutions are particularly evident with metastable forms. Possibility of wide departure from equilibrium behavior is shown for “stabilized” samples in the SOS-SSS case; low melting components melted out of solid solution below the system's complete melting point are able to reenter the solid solution phase only to a limited extent.
TL;DR: The significance of cyclic fatty acids in industrial processes is discussed in this article, where a technique has been devised for a) aromatization of the resultant cyclohexadiene, b) oxidation to orthophthalic acid and c) characterization of the acid as the anhydride and the imide.
Abstract: 1.
Methyl eleostearate has been thermally cyclized in good yields, and a concentrate of the cyclic product has been prepared.
2.
Using small amounts, a technique has been devised for a) aromatization of the resultant cyclohexadiene, b) oxidation to orthophthalic acid, and c) characterization of the acid as the anhydride and the imide.
3.
The significance of cyclic fatty acids in industrial processes is discussed.
TL;DR: In this article, a number of highly purified fatty acids have been prepared and their solubilities determined in six common organic solvents within the temperature range from 10° to −70°.
Abstract: A number of highly purified fatty acids have been prepared and their solubilities determined in six common organic solvents within the temperature range from 10° to −70°. The acids studied were palmitic, stearic, oleic, elaidic, petroselinic, petroselaidic, linoleic, stearolic, arachidic, eicosenoic, behenic, erucic, and brassidic. The solvents used were methanol, ethyl acetate, diethyl ether, acetone, toluene, and n-heptane, representing six different solvent types. A limited study was also made with a series of hydrocarbon solvents in order to note any effects of solvent structure on fatty acid solubility. Data are discussed with respect to their application in separating various fatty acid mixtures by low temperature crystallization.
TL;DR: In this article, the authors describe the high pressure homogenization equipment used and the actual procedure followed in the preparation of fat emulsions suitable for intravenous nutrition, which contain 10-15% oil (w/v) dispersed in particles less than one micron in diameter.
Abstract: Descriptions are given of the high pressure homogenization equipment used and of the actual procedure followed in the preparation of fat emulsions suitable for intravenous nutrition. Such emulsions contain 10–15% oil (w/v) dispersed in particles less than one micron in diameter. They are made under nitrogen and subsequently autoclaved to ensure sterility.
TL;DR: Disodium 2-sulfoethyl α -sulfopalmitate, disodium 1-methyl-2-sulcoethyl α-Sulfonated acid with sodium isethionate was made from sodium 2-hydroxypropanesulfonate.
Abstract: Disodium 2-sulfoethyl α-sulfopalmitate, disodium 2-sulfoethyl α-sulfostearate, and disodium 2-sulfoethyl α-sulfobehenate were prepared by esterification of the corresponding α-sulfonated acid with sodium isethionate. Disodium 1-methyl-2-sulfoethyl α-sulfostearate was made from sodium 2-hydroxypropanesulfonate. The esters were found to be readily soluble surface-active agents and detergents, very responsive to building with inorganic phosphates and sulfates.
TL;DR: The increase in linoleate oxidation catalysis of copper-proteins compared to ionic copper is ascribed to increased ease of formation and increased stability of the intermediate complex of linoleates peroxide-copper-protein.
Abstract: Copper-proteins formed by the binding of copper ions to conalbumin, serum albumin, or caseinate are more effective catalysts for linoleate oxidation than is copper alone. The main product is conjugated diene linoleate hydroperoxide. Hemocyanin shows similar catalytic activity.
TL;DR: In this article, a study of the relation between processing conditions and the chemical characteristics of cottonseed meals and oils produced by prepressing-solvent extraction was made. But the results were limited to 11 mills.
Abstract: A study has been made of the relation between processing conditions and the chemical characteristics of cottonseed meals and oils produced by prepressing-solvent extraction. Twenty-six complete sets of mill samples of known processing history and representative of the production at 11 mills were used in the investigation.
TL;DR: In this paper, a method for quantitative determination of ethylene oxide adducts is described by precipitation in hydrochloric acid solution with a known quantity of ferrocyanic acid, filtration, and titration with zinc sulfate.
Abstract: A method for quantitative determination of ethylene oxide adducts is described. By precipitation in hydrochloric acid solution with a known quantity of ferrocyanic acid, filtration, and titration with zinc sulfate, the consumption of ferrocyanic acid can be determined. From the results a m.d. of less than 8% was calculated, the corresponding figure for adducts containing more than 9 ethylene oxide units does not surpass 5%. The reaction takes place on the ethylene oxide chain in the compound. To precipitate an adduct containing 6 units ethylene oxide approximately one mole of ferrocyanic acid is necessary.
TL;DR: In this article, a simple laboratory testing apparatus and its use have been described, with relatively few pounds of material it is possible to evaluate many preparation and filtration variables and to predict with a fair degree of accuracy the behavior of a continuous horizontal vacuum filter.
Abstract: A simple laboratory testing apparatus and its use have been described. With relatively few pounds of material it is possible to evaluate many preparation and filtration variables and to predict with a fair degree of accuracy the behavior of a continuous horizontal vacuum filter. It is felt that such a unit will be invaluable for use in commercial plants, especially during the start-up operations of a new plant. The bench-scale unit should also find application in connection with other processes employing the unit operations of extraction and filtration.
TL;DR: The most commonly used methods for assessing stability or rancidity of a fa t or f a t y foods are the: active oxygen method, Schaal oven test, thiobarbituric acid test, carbonyl test, and peroxide value as mentioned in this paper.
Abstract: T HE DETECTION of advanced stages of rancidi ty in a fat or fa t ty food has never been a problem for people with normal olfactory senses. The sharp pungent odors mixed with certain stale and musty odors have provided tell-tale evidence of rancidi ty throughout the ages. That this is not always regarded as undesirable is evidenced by the fact that some peoples have deliberately aged fats before using them. The p r e s e n t d a y p r e f e r e n c e s f o r p r o d u c t s w i t h f r e s h bland flavors and odors requ i re t ha t we have ways and means for evaluating keeping quali ty and incipient rancidity. The history of objective tests for rancidi ty and for keeping quali ty begins over 50 years ago with development of the Kreis test (12). Then the oxygen absorpL. R. Dugan Jr. tion methods for determining the resistance of a fat to rancidi ty were developed. The baking indust ry developed the oven test for rancidity, which became commonly known as the "Schaa l Oven Tes t " (10) although there is no published reference by the originator. Great strides forward were made with the development by Lea (14) and later by Wheeler (29) of quanti tat ive methods for peroxide determinatio~J. These were followed by the accelerated method known as the " S w i f t Tes t " or the "Act ive Oxygen Method" by King, Rosehen, and I rwin (11). The rapidi ty and reproducibil i ty of this method coupled with the organoleptic correlation of rancidi ty with developed peroxides made it extremely useful for evaluation of the resistance of a fa t to rancidi ty and especially for the evaluation of the relative effectiveness of antioxidants in fats. Many early workers recognized "the presence of aldehydes and /o r ketones in autoxidized fats and at tempted to develop objective tests based on them. I t was only af ter the development of quantitative colorimetric tests for carbonyl compounds in low concentrations that substantial agreement between carbonyl content and organoleptie evaluation of rancidity was accomplished. The most commonly used methods for assessing stability or rancidi ty of a fa t or f a t t y foods are the: active oxygen method, Schaal oven test, thiobarbituric acid test, carbonyl test, and peroxide value. The Active Oxygen Method. This method is based on the principle that the aging and rancidification of a fat is greatly accelerated by aeration in a tube held at a constant elevated temperature, While an organoleptic evaluation may be used to indicate the rancid point, the results are based on the peroxide content of the fat af ter correlation with organoleptic rancidity. The apparatus consists of a constant temperature bath and an aerat ing t ra in contrived to deliver a continuous flow of air to the sample at a constant rate. hl i t ial ly the heat was supplied by an oil bath surrounded by a hot water jacket maintained at a constantly boiling temperature. Recent refinements use an oil bath with a st irrer and a thermoregulator for precise temperature control. The aerating t ra in has a bottle with water through which air is passed into another bottle containing 2% potassium dichromate with 1% sulfuric acid. These bottles serve as scrubbers to pu r i fy the air before it is led into the manifolds, to which the sample tubes are connected. A tube leads from the scrubber to two cylinders connected in series and each filled with water to the height necessary to provide a suitable pressure head for forcing air through each tube leading into the sample tubes. The rate of air flow was established at 2.33 ec. per second through each sample. This flow rate is controlled by the pressure head and by inserting a piece of capillary tubing in the line leading from the manifold into the sample tube. The capillary tube is cut to length according to the size of the capillary to permit the established rate of air flow, The determinat ion may be made by measuring 20 cc. of liquid fat into three 8-in. by 1-in. tubes. One tube is heated to tempera ture in an external water or steam bath and then placed in the oil bath; and the air tube is connected to the tube which projects through the sample to near the bottom of the sample tube. The time of the beginning of air flow is recorded. At suitable time intervals of 1 or more hours, the remaining tubes progressively may be started. When the effluent air f rom the first tube has the characteristic rancid odors, a sample may be taken from each tube for a peroxide determination. By a proper choice of s tart ing intervals for the tubes containing a given sample, it is possible to bracket the end point of 20 milliequivalents of peroxide per 1,000 g. of fa t (animal fats) and then by periodic sampling from the remaining tubes accurately to determine the time for development of the necessary peroxide content. Variations of this method are practiced. A eommonly used variat ion is that reported by Riemenschneider et al. (23), which uses only one tube and periodic sampling of 0.2-g. samples for determination of the peroxide value. These workers introduced the all-glass aeration tubes in place of the rubber-stoppered test tubes and added a water condenser and extra air dist r ibut ing bottle to prevent entrained moisture in the air-distr ibuting system from clogging the capillary orifices. A major contribution to application of the A.O.M. to control work was made by Mehlenbacher (16), who found that the time for rancidification could be shortened by a factor of 2.5 by elevating the incubation temperature to 110~ ~t is obvious from this that temperature control is critical for reproducibi l i ty of results since only a small change in temperature may introduce a wide variat ion in end-point. There are numerous factors which can influence the rate of rancidification of a fat, and the temperature effect cited is one. Other factors are light, availabili ty of oxygen, surface factors, the presence of natural or synthetic antioxidants, the nature of the fat, and trace metal or metal contact catalysis. For reproduei-
TL;DR: The rates of polymerization of alpha and beta eleostearates agree with second order kinetics, as would be expected for a bimolecular Diels-Alder addition, and it is suggested that conjugation is the slow rate determining monomolecular reaction, as has been proposed for the non-conjugated linoleate isomers.
Abstract: The rates of polymerization of alpha and beta eleostearates agree with second order kinetics, as would be expected for a bimolecular Diels-Alder addition. The all-trans, beta isomer reacts faster than thecis, trans, trans alpha isomer, in agreement with knowncis, trans effects on diene activity.
TL;DR: In this paper, relative values for the carotene-stabilizing effects in mineral oil solutions of a number of bisphenol derivatives were determined, and certain relationships between molecular structure and antioxidant activity were observed.
Abstract: Relative values for the carotene-stabilizing effects in mineral oil solutions of a number of bisphenol derivatives were determined. Certain relationships between molecular structure and antioxidant activity were observed. Alkyl substitutions in the reactiveortho andpara positions were shown to improve the stabilizing efficiency of the compounds studied. High activities were obtained with bisphenols linked by methylene or sulfur. Several of the most effective antioxidants were found to be also effective for stabilizing carotene in alfalfa meal.
TL;DR: In two series of experiments, marine-animal-oil fatty acids were fractionated with urea using methanol as solvent as discussed by the authors, and the results showed that urea was a better solvent than water.
Abstract: In two series of experiments, marine-animal-oil fatty acids were fractionated with urea using methanol as solvent.
TL;DR: In this article, the glyceride composition was altered considerably and showed close agreement with values calculated for random distribution, accompanied by significant changes in physical character as shown by consistency numbers, dilatometric and micropenetration measurements, and cooling curves.
Abstract: Treatment of lard with sodium methylate did not affect fatty acid composition nor the usual chemical constants and melting points. The glyceride composition however was altered considerably and showed close agreement with values calculated for random distribution. This change in glyceride composition was accompanied by significant changes in physical character as shown by consistency numbers, dilatometric and micropenetration measurements, and cooling curves.