bluuebunny/crossref_metadata_2025 huggingface dataset:
Oxidation of acylglycerols and phosphoglycerides by soybean lipoxygenase
Authors: Piazza George J. , Nuñez Alberto
Published: June 2007

Lipoxygenase (EC 1.13.11.12) catalyzes the incorporation of oxygen into polyunsaturated fatty acids, resulting in the formation of their corresponding hydroperoxides. The ability of a commercial preparation of soybean (Glycine max L. Merr.) lipoxygenase to catalyze the oxidation of acylglycerols and phosphoglycerides was investigated. The oxidation rate of trilinolein increased nearly 100% when 5 mM deoxycholate was added to the reaction medium. With further increases in the concentration of deoxycholate, the oxidation rate decreased slightly. The pH profile of trilinolein oxidation was bell‐shaped. The rate of oxidation was maximal at pH 8, and it decreased to near zero at pH 5 and pH 11. Even under optimal conditions, the rate of trilinolein oxidation was only 3% of that of linoleic acid, and analysis of time course data showed that, at most, 15% of available linoleate was oxidized. In contrast to the slow rate of trilinolein oxidation, tested phosphoglycerides and diacylglycerols were oxidized at moderate rates. The rate of phosphoglyceride oxidation depended upon the structure of the polar head group and varied between 7–28% of the rate of linoleic acid oxidation. Diacylglycerols reacted at a rate that was 40% of that of linoleic acid. Analysis of the time course of 1,3‐dilinolein oxidation showed that as much as 67% of the available linoleate could be converted to the corresponding hydroperoxide. Analyses by high‐performance liquid chromatography revealed that more than 20% of the 1,3‐dilinolein was converted to unidentified products that are not hydroperoxides.
Influence of avocado oil processing on the nature of some unsaponifiable constituents
Authors: Farines M. , Soulier J. , Rancurel A. , Montaudoin M. G. , Leborgne L.
Published: June 2007

The unsaponifiable part of avocado pear oil, after heating during extraction and processing, contains an abundant fraction that has never been found in the unsaponifiable part of usual vegetable oils nor in cold‐pressed avocado oil. Nine components were detected. Eight of them could be identified through chromatographic fractionations and spectroscopic analysis, mainly by mass spectrometry and proton nuclear magnetic resonance. These products are characterized by a homogeneous structure. A furyl nucleus is substituted in position 2 by an aliphatic, mono‐ or polyunsaturated chain. The chainlength varies from 13 to 17 carbon atoms. The carbon number is always odd. The significance of these components in the biological effects of avocado oil unsaponifiables is still being studied.
High‐performance liquid chromatography analysis of peanut phospholipids. II. Effect of postharvest stress on phospholipid composition
Authors: Singleton J. A. , Stikeleather L. F.
Published: June 2007

Peanuts are harvested in late September, and sometimes the harvest season can extend through most of October. When weather patterns delay harvest, the result may cause an immature crop, curing problems, rain damage, and freeze damage. All of the above stress situations can affect oil quality and flavor of the peanuts by altering phospholipid composition. Such changes are related to refining problems as well as flavor problems. A new high‐performance liquid chromatography (HPLC) method was used for the analysis of phospholipids from postharvest stressed peanuts. The concentrations of phosphatidic acid (PA), phosphatidylethanolamine (PE), and phosphatidylcholine (PC) were higher in immature seed when compared to mature seed. A slight increase in concentration was observed for phosphatidylglycerol (PG), and a decrease in phosphatidylinositol occurred in immature peanuts. All phospholipids increased in concentration except PG when peanuts were cured at a high temperature (40°C). When peanut seeds were frozen at −16°C (before curing), a significant increase in concentration was observed for PA and PG, whereas the concentrations of PC and PE decreased to very low levels when compared to the control. Where concentration permitted, molecular species were separated on a reverse‐phase column by HPLC.
Sterol composition inCoincya (Brassicaceae)
Authors: Vioque Javier , Pastor Julio , Vioque Eduardo
Published: June 2007

Sterol composition was determined for seed oils and leaf waxes in eleven taxa belonging to the genusCoincya (Brassicaceae) on the Iberian Peninsula (Spain and Portugal). Seed sterols ranged from 1.2 to 6.7%. The major components were sitosterol (42.6–54.6%), campesterol (20.4–33.2%), and brassicasterol (10.8–23.5%). In leaf waxes, the major free sterols were sitosterol (40.9–74.2%), campesterol (9.6–17.0%), and cholesterol (4.6–17.0%). In leaf wax esters, the major sterols were sitosterol (22.2–56.5%), cholesterol (7.3–32.8%), and campesterol (5.8–25.6%). An apparent substitution of brassicasterol in free sterols from the seeds by cholesterol in free sterols from the leaves was observed. There was an increase of cholesterol in sterols from leaf wax esters with respect to free sterols from leaves and seeds. InC. monensis subsp.nevadensis, the composition in sterols from leaf waxes may be an adaptation to low temperatures.
9H‐xanthene‐2,7‐diols as antioxidants for autoxidation of linoleic acid
Authors: Yamamura Tatsuo , Arashima Masaki , Nakatani Kazumi , Ishida Takafumi , Yamada Fukiko , Nishiyama Tomihiro
Published: June 2007

The antioxidant activities of 9H‐xanthene‐2,7‐diols and α‐tocopherol were studied during the oxidation of linoleic acid in a homogeneous solution and in an aqueous micelle dispersion. The antioxidant activities of 9H‐xanthene‐2,7‐diols for both systems were 1.0–2.4 times greater relative to α‐tocopherol. In addition, the 1,3,4,5,6,8‐hexamethylxanthene‐2,7‐diol showed less cytotoxicity toward human fibroblasts than did 2,6‐di‐t‐butyl‐4‐methylphenol.
cis‐trans isomerization of unsaturated fatty acids withp‐toluenesulfinic acid
Authors: Snyder J. M. , Scholfield C. R.
Published: June 2007

Elaidination of unsaturated fatty acids usingp‐toluenesulfinic acid yielded 77–80% totaltrans unsaturation in the products. Results from reactions with monoene, diene, and triene isomers indicated that only geometric isomerization takes place. Each double bond isomerized randomly and independently in the polyunsaturated fatty acids. Reactions proceeded quickly, and the method proved convenient and reliable.
Adsorption of β‐carotene: II. On cation exchanged bleaching clays
Authors: Liew K. Y. , Tan S. H. , Morsingh F. , Khoo L. E.
Published: June 2007

X‐ray diffraction patterns of a number of commercial bleaching earths indicate that they consist mainly of montmorillonite mixed with smaller amount of kaolinites as well as mica, quartz and cristobalite. The active sites in these earths for the adsorption of β‐carotene are identified through ion exchange and found to be the protonic sites and some metallic ions. The efficiencies of the various cations in imparting activities to the earths are found to be in the order Mg2+ > Fe3+ > H+ > Ca2+ > Na+. For Fe3+ and H+ exchanged clays, the activity was found to be linear function of the concentration of these ions. The high activities of Mg2+ and Ca2+ exchanged clays are discussed.
A simple method for estimating carbonyl content in peroxide‐containing oils
Authors: Chiba Toshiyuki , Takazawa Makiko , Fujimoto Kenshiro
Published: June 2007

A simple method is described for the estimation of carbonyl content in peroxide‐containing oils. In this method, peroxides, which interfere with carbonyl determination, are reduced with triphenyl phosphine prior to carbonyl determination. Carbonyl content is measured by a colorimetric 2,4‐dinitrophenyl hydrazone procedure. Neither triphenyl phosphine nor triphenyl phosphine oxide, oxidation products of triphenyl phosphine by reaction with peroxides, interfere with the measurement of carbonyl content. The method is applicable to several kinds of oxidized oils in any oxidation stage.
Heats of combustion of fatty esters and triglycerides
Authors: Freedman B. , Bagby M. O.
Published: June 2007

Gross heats of combustion (HG) have been measured for three classes of fatty esters and two classes of triglycerides (TGs). The esters included saturated methyl esters, Me 6:0–22:0; saturated ethyl esters, Et 8:0–22:0; and unsaturated methyl esters, Me 12:1–22:1, Me 18:2 and Me 18:3. The TGs included the saturated TGs, C 8:0–22:0, and unsaturated TGs, C 11:1, C 16:1, C 18:1, C 18:2, C 18:3, C 20:1 and C 22:1. HG were measured in a Parr adiabatic calorimeter according to a modification of ASTM D240 and D2015. Linear regression analysis (LINREG) yielded equations that related HG to carbon number (CN) or chain length, electron number (EN) or number of valence electrons and molecular weight (MW). Calculated HG values from CN, EN, or MW were nearly identical. Thus, any one of these three variables can be used to predict HG satisfactorily. R squared values for all equations were 0.99. Equations for correlating HG of saturated or unsaturated TGs with molecular characteristics of these molecules have not been reported. With LINREG, we developed equations that permitted predictions of HG from structures of the saturated and unsaturated TGs. Equations for predicting HG of methyl and ethyl esters were compared to those in the literature and were found to be more accurate and precise.
Polymorphism of POP and SOS III. Solvent crystallization of β2 and β1 polymorphs
Authors: Arishima T. , Sato K.
Published: June 2007

Single crystals of β1 and polycrystals of β2 of POP and SOS were obtained from acetonitrile solution. The crystallization behavior of the two polymorphs was almost the same in POP and SOS; rapid cooling of the solution preferentially crystallized the metastable β2 form, and the most stable β1 form crystallized in a very low solute concentration at the expense of β2, via solution‐mediated transformation. The single crystal of β2 revealed needle‐like irregular shape, whereas well‐defined slender rhombic shape was observed in β1. The solubilities of the β1 forms of POP and SOS in tetradecane solution were precisely measured in a temperature range of 10∼20°C. This study showed that the solvent crystallization was the single way to grow the β1 crystal, since melt‐cooling and melt‐mediated transformation did not crystallize β1 both in POP and SOS.
Fatty acid composition of oil from soybean seeds grown at extreme temperatures
Authors: Rennie B. D. , Tanner J. W.
Published: June 2007

Temperature during seed development is known to influence the level of the various fatty acids in soybean [Glycine max (L.) Merr.] oil. In order to determine the range of values that can be obtained for each fatty acid, five lines (A5, C1640, N78‐2245, PI 123440 and PI 361088B) known to possess low linolenic acid (18:3) levels, one line (A6) known to possess a high stearic acid (18:0) level, and two cultivars (Century and Maple Arrow) were grown at 40/30, 28/22, and 15/12°C day/night. At 40/30°C, high oleic acid (18:1), low linoleic acid (18:2), and low linolenic acid levels were obtained that were beyond the range of levels reported for the soybean germplasm. The linolenic acid levels for A5, C1640 and N78‐2245 grown at 40/30°C were below 2.0%, and are the lowest values reported for soybean oil. A6 displayed a high level of stearic acid at 28/22 and 40/30°C but displayed a relatively low level at 15/12°C. This indicates that temperature may affect the expression of thefasa allele, which is responsible for high stearic acid levels in A6. The linolenic acid levels of PI 361088B and C1640, both possessing thefan allele, were the lowest for all lines grown at 15/12°C. Therefore, thefan allele is an appropriate source for the development of low linolenic acid lines adapted to cool areas.
Effect of alkyl carbon chain length and ethylene oxide content on the performance of linear alcohol ether sulfates
Authors: Cox Michael F.
Published: June 2007

A series of linear alcohol ether sulfates varying in alkyl carbon chain length and ethylene oxide content was evaluated with respect to surface activity, viscosity, foaming, and detergency. Performance data agree well with surface property data. A low level of EO is best in terms of effectiveness and efficiency in lowering surface tension, which is why a low‐mole ether sulfate salt‐thickens better, produces foam which is more tolerant of soil, and gives good detergency performance. A lauryl‐range alkyl carbon chain length is best for foaming and salt‐thickening, but a higher carbon chain length appears to be better for detergency performance.
Composition of a liquid crystalline phase formed between aqueous surfactant solutions and oily substances
Authors: Yatagal M. , Komakl M. , Nakajima T. , Hashimoto T.
Published: June 2007

Differential scanning calorimetry (DSC) was applied to determine the composition of a liquid crystalline (LC) phase formed between an aqueous solution of sodium dodecyl sulfate (SDS) and octanol under various conditions. The concentrations of three components, SDS, water, and octanol, contained in the LC phase were determined approximately from the DSC melting peak areas.

The composition of the LC phase varied with time within the LC region in the phase diagram reported in the literature. The change of the octanol concentration in the LC phase was correlated to the process in which octanol is gradually incorporated into the LC phase and then released into the exterior aqueous SDS solution. Increasing temperature facilitated such a process.
The calcium binding capacity of polycarboxylates
Authors: Richter Fellx H. , Winkler Ekhard W. , Baur Richard H.
Published: June 2007

It can be shown both theoretically and experimentally that calcium carbonate forms during the titration of polycarboxylates by calcium with carbonate as the indicator, and that the calcium carbonate is dispersed by the polycarboxylate. If the dispersing capacity of the polymer exceeds the level of calcium carbonate present, the precipitation of the calcium salt of the polymer is observed as the end point. If the quantity of carbonate is increased to a level greater than that of the dispersing capacity of the polymer, the precipitation of calcium carbonate is observed as the end point, and we term the result of this titration the “calcium carbonate dispersing capacity.”
Oxidative cyclization of 1‐octadecanol and hydroxy fatty esters with lead tetraacetate
Authors: Hashmi M. , Khan M. , Ahmad M. S. , Ahmad F. , Osman S. M.
Published: June 2007

Oxidative cyclization of methyl 2‐hydroxyoctadecanoate, methyl 10‐hydroxyundecanoate and 1‐octadecanol produced a good yield of the corresponding tetrahydrofuran (THF) derivatives characterized successively as methyl 2,5‐epoxyoctadecanoate, methyl 7,10‐epoxyundecanoate and 1,4‐epoxyoctadecane. The structure of these cyclic derivatives have been established by elemental analyses and spectral studies.
Addition of aromatic compounds to oleic acid catalyzed by heterogeneous acid catalysts
Authors: Kohashi Hitoshi , Foglia Thomas A.
Published: June 2007

The addition of aromatic compounds to the double bond of oleic acid was studied using solid acid catalysts. For example, in the presence of an acid clay catalyst (bentonite), phenol reacted with oleic acid to yield 96% of an alkylphenol addition product. When toluene was used as the aromatic reactant, however, the yield of alkylbenzene addition product was less than 2%. In this instance, the major reactions observed were elaidinization and migration of the double bond of oleic acid. The addition of phenol to oleic acid in greater than 95% yield also was accomplished with the use of a sulfonic acid ion‐exchange resin catalyst. This same catalyst also catalyzed the addition of toluene and benzene to oleic acid to yield 82% and 22%, respectively, of alkylbenzene‐type addition products. In the latter instances, the major side product formed was γ‐stearolactone. Capillary gas chromatographic (GC) analyses of the alkylbenzene addition products obtained showed them to be mixtures of positional isomers. The isomer distributions were subsequently determined by GC‐mass spectrometry (MS).
Phytate Removal from soybean proteins
Authors: Brooks J. R. , Morr C. V.
Published: June 2007

The ability of Ca++, Ba++ and Zn++ ions to complex with and precipitate phytate ions was investigated as a possible approach for producing phytate‐reduced soy‐protein isolates. The treatments involved adding divalent cation reagents to mildly alkaline soyprotein extracts, or using mildly alkaline solutions of the cation reagent as protein extractant. Treatments used up to 5% (w/v) divalent cation reagent in dilute NaOH at pH 8–9 at room temperature with stirring for 1 hr. The proteins that remained soluble, or that were extracted following the above treatments, were further fractionated by dialysis against distilled water and then adjusted to the isoelectric pH of 4.5 with HCl. All treatments generally precipitated 15–90% of the total extracted proteins. The resulting phytate‐reduced fractions had their total P reduced by ca. 30–74%, but their yields were reduced to only 11–85% of the total extract proteins. On the basis of these findings and on other adverse factors, e.g., toxicity, possible off‐flavor and reduced functionality from residual precipitant ions, the divalent cation‐fractionation method is not recommended for producing phytate‐reduced soy‐protein isolates for food use.
HBr‐Reactive acids ofMalva sylvestris seed oil
Authors: Mukarram Mohammad , Ahmad Ishtiaque , Ahmad Mashood
Published: June 2007

Malva sylvestris seed oil contained 5.6% sterculic, 11.0% malvalic, 1.6% vernolic, 15.6% lauric, 6.6% myristic, 26.6% palmitic, 5.6% palmitoleic, a trace of stearic, 23.0% oleic and 4.0% linoleic acids. The co‐occurrence of malvalic and sterculic acids was established by gas liquid chromatography (GLC) of the silver nitrate‐methanol treated esters usingSterculia foetida esters as the reference standard. Co‐occurrence of epoxy acid (vernolic acid) was confirmed withVernonia anthelmintica as the lipid standard.
A rapid micromethod for the quantitative analysis of jojoba wax and its components
Authors: Tonnet M. L. , Dunstone R. L. , Shani A.
Published: June 2007

A method for the routine determination of jojoba wax ester composition and the ethanolysis products of these esters is described. In the recommended procedure, single or half seeds are crushed onto filter paper disks to provide duplicate 10–20 mg samples of the wax. One paper is extracted with petroleum ether for wax ester analysis and the second sample is transesterified in a sealed bottle using 5% HCl in ethanol at 80 C for 1–2 hr. This preparation is extracted with NaCl and petroleum ether, neutralized with potassium bicarbonate and dried with anhydrous sodium sulfate. The fatty acid ethyl esters and free alcohols are determined by gas chromatography (GC). The method requires only small amounts of seed material, provides duplicate samples of the wax, simplifies the ethanolysis procedures and reduces the time needed for the removal of the acid catalyst.
A flavonoid antioxidant in Spanish peanuts(Arachia hypogoea)
Authors: Pratt D. E. , Miller E. E.
Published: June 2007

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.
Distribution of ammonia‐related aflatoxin reaction products in cottonseed meal
Authors: Park Douglas L. , Lee Louise , Koltun S. A.
Published: June 2007

The fate of aflatoxin during ammoniation of contaminated cottonseed meal was studied under conditions approximating those approved for commercial ammoniation of nonaflatoxin‐contaminated meal. Uniformly ring‐labeled14C‐aflatoxin B1 was added to 27.7 kg meal (14% moisture) that contained ca. 4000 µg naturally incurred aflatoxin B1/kg. Distribution of the radiolabeled compound was used to trace the modification of aflatoxin B1 after treatment with 4% ammonia at 40 psi, 100 C for 30 min. This treatment reduced the chemically detected aflatoxin B1 to less than 4 µg/kg. In control nonammoniated meals, 90% of the radiolabeled material was accounted for in the methylene chloride extract. Duplicate 2‐kg samples of the ammoniated meal were fractionated and the distribution of radioactivity was determined. Ca. 86% of the radioactivity was detected in the meal after initial air‐drying. Ca. 25% of the added radioactivity was extracted from the air‐dried meal with methylene chloride and another ca. 5% was extracted from this residue with methanol. Weak acid released 3% of the added radioactivity from the residue after methanol extraction, bicarbonate released 1% and Pronase digestion, including methylene chloride extraction of the residue, accounted for nearly 19% of the total added radioactivity. Only 37% of the added radioactivity remained in the meal matrix following solvent extractions and chemical and enzymic treatments.
A method for the separation of seed oil steryl esters and free sterols: Application to peanut and corn oils
Authors: Worthington R. E. , Hitchcock H. L.
Published: June 2007

A method for separating and quantitating seed oil steryl esters and free sterols was developed using a combination of preparative column, thin layer (TLC), and gas liquid chromatography (GLC). Cholesteryl heneicosanoate and cholesterol served as internal standards. The method was applied to corn‐oil samples (Mazola, Kroger) obtained from the local market and peanut‐oil samples prepared in the laboratory from commercial varieties of peanuts (Florunner, Starr). Concentration (mg/100 g oil; mean ± SD) of steryl esters and free sterols in the 4 oils were: Mazola, 1420±40 and 370±8; Kroger, 950±40 and 320±4; Florunner, 74±0.5 and 150±3; and Starr, 51±0.5 and 130±2. Sitosterol was the major sterol in both the free sterol and steryl ester fractions of all oils and together with campesterol, stigmasterol and Δ5‐avenasterol made up 90–95% of all sterols. Steryl esters of peanut oil contained higher proportions of linoleic acid and long‐chain acids (C20–C24) than did whole oil. Corn‐oil steryl esters also contained a higher proportion of linoleic acid than did whole oil. Squalene was the major hydrocarbon of all oils with the remaining hydrocarbon fraction consisting of a mixture of compounds.
The AOCS smalley program
Authors: McEwan J. W.
Published: June 2007

This program is named for Frank N. Smalley, a charter member of AOCS. In 1909, he was chief chemist for the Southern Cotton Oil Company, the same year in which AOCS was formed. Smalley checked the proficiency of his firm's laboratories by distributing weekly meal samples that had been prepared in his Savannah laboratory. Other analytical chemists saw the value of such a program and asked to participate. In 1915, the Uniform Methods Committee, under Dr. Smalley, adopted this program. In 1955, the name was formally shortened to the Smalley Committee. It continues to function largely with the aid of volunteer help. AOCS is greatly indebted to the people and industries who give of their time and talents. In 1981, an ad‐hoc committee reviewed the Smalley Committee and each of the series involved and declared the program was functioning well and carrying out its intended purpose.
Quality control in the use of deep frying oils
Authors: Stevenson S. G. , Vaisey‐Genser M. , Eskin N. A. M.
Published: June 2007

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.
Conditioning of oil‐bearing materials for solvent extraction by extrusion
Authors: Rittner Herman
Published: June 2007

A new procedure, based on extrusion, was developed to prepare soybeans for direct solvent extraction. The procedure eliminates the need of controlled cracking, partial shell remotion, heating and flaking, requiring only an adequate communition to particles passing Sieve USS 14 followed by extrusion in a specially developed extruder. Extruded soybeans were obtained in the form of hard and porous agglomerates, without any dusting tendency, higher extraction, draining and percolation rates, lower solvent hold up and higher apparent density than the best possible flakes. Extruded soybeans were processed by solvent extraction in batch and continuous industrial installations, enabling substantial increases in capacity (up to 100%) and reduction in overall steam consumption (up to 30%) when compared with flakes processing. Extracted oil from extruded soybeans seems to show lower levels of gums and toasted meal at higher soluble protein levels for the same urease activity. Peanut press‐cakes were preconditioned by extrusion before solvent extraction in batch‐type installations, enabling a substantial reduction in residual oil for similar conditions with nonextruded press‐cake. For existing plants, the new procedure allows a substantial increase in plant capacity and lower steam consumption. For new plants, the new procedure allows substantial capital savings in equipment and space. The new procedure enables soybean processing by direct solvent extraction in small batch‐type installation, which may be very convenient for some underdeveloped areas.
Confectionery fat analysis with high performance liquid chromatography
Authors: Kimmey R. L. , Perkins E. G.
Published: June 2007

Natural triglyceride mixtures have been analyzed by a variety of techniques. Earlier methods, such as crystallization, were unsuitable because they were very time‐consuming, required large amounts of material and were not reproducible. Later advances in chromatography gave successful separations of triglycerides but required a combination of techniques to give suitable separations. High performance liquid chromatography (HPLC) with very efficient columns has been successfully applied to triglyceride separations on a routine basis. In the present work, triglycerides of cocoa butter as well as several replacement fats were separated by HPLC. The system consisted of a highly efficient column packed with octadecylbonded spherical silica (5 µ) and a mobile phase composed of acetone and acetonitrile. Peaks corresponding to eluted components were collected and their composition determined by gas chromatography (GC) of the corresponding methyl esters to allow unambiguous assignment of triglyceride structure to the components. A profile of the triglycerides present in such fats can be obtained within 30 min.
Short‐chain phorbol ester constituents of croton oil
Authors: Marshall Gary T. , Kinghorn A. Douglas
Published: June 2007

Five phorbol diesters, three 4‐deoxy‐4α‐phorbol diesters, two phorbol monoesters, and one 4‐deoxy‐4α‐phorbol monoester were isolated from a commercial sample of croton oil and characterized spectroscopically. Their purification was achieved using combinations of droplet countercurrent chromatography, low‐pressure column chromatography over phase‐bonded silica gel, and preparative thin layer chromatography. All of these isolates were shown to possess short‐chain ester functionalities, with 12‐O‐tiglylphorbol‐13‐isobutyrate, 12‐O‐(2‐methyl)butyrylphorbol‐13‐isobutyrate, 12‐O‐(2‐methyl)butyrylphorbol‐13‐acetate, 12‐O‐tiglyl‐4‐deoxy‐4α‐phorbol‐13‐isobutyrate, 12‐O‐tiglyl‐4‐deoxy‐4α‐phorbol‐13‐acetate, 12‐O‐(2‐methyl)butyryl‐4‐deoxy‐4α‐phorbol‐13‐acetate, phorbol‐12‐tiglate and 4‐deoxy‐4α‐phorbol‐13‐acetate being new compounds.
High performance liquid chromatography of the tocols in corn grain
Authors: Weber Evelyn J.
Published: June 2007

A sensitive and selective method was developed for analyzing the tocol isomers in corn grain by high performance liquid chromatography (HPLC) with fluorescence detection. The relative proportions and the total amounts of the tocol isomers (α‐tocopherol, α‐tocotrienol, γ‐tocopherol and γ‐tocortrienol) varied greatly among the 15 corn inbreds that were examined. Although γ‐tocopherol has traditionally been considered to be the predominant vitamin E isomer in corn, inbreds with equal or higher levels of α‐tocopherol have been discovered. No tocotrienols were found in corn germ oil, only α‐and γ‐tocopherols. Analysis of the tocopherols of the germ oils of inbreds and their reciprocal crosses indicated that the proportions of the α‐ and γ‐isomers and the total amount of the tocopherols are heritable.
Effects of planting date and irrigation on wax content of sunflower‐seed oil
Authors: Morrison W. H. , Sojka Robert E. , Unger Paul W.
Published: June 2007

Seed from sunflower grown at Bushland, TX, in 1980 and 1981 and at Florence, SC, in 1982 were evaluated for the influence of date of planting and irrigation on wax production. Wax content of the hull and oil was found to be ca. 10% lower in samples from irrigated than from nonirrigated sunflowers; however, none of the sunflower planted on different dates were under severe moisture stress from bloom to harvest. Although the highest positive correlation was found between the linoleic acid content of the oil and the wax content of the hull, those factors that favored high oil percentage also favored low wax content.
Physical refining of edible oil
Authors: Tandy D. C. , Mcpherson W. J.
Published: June 2007

Physical refining of edible oils has received renewed interest since the early 1970s when the process was reintroduced on a large scale to refine palm oil in Malaysia. Subsequent laboratory and field tests have also shown that physical refining can be used as a substitute for caustic or chemical refining, not only for high free fatty acid (FFA) oils such as palm, but also on low FFA oils such as soybean oil. In either case, the physical refining system results in lower oil loss than chemical refining and also eliminates pollution problems associated with soapstock acidulation. In physical refining, however, the oil pretreatment and efficiency of the distillation are two very important factors that must be considered to guarantee continuous production of high quality products. This paper reviews the physical refining system as it is today and how it can be used on two different edible oils. An actual case study showing the effects of the pretreatment in a commercial operation is also presented.
Estimation of cetane index for esters of fatty acids
Authors: Klopfenstein W. E.
Published: June 2007

Cetane indexes have been calculated for the esters of the individual saturated fatty acids in the C8‐C24 range plus palmitoleic, oleic, linoleic, and linolenic acids. Two methods were used for these calculations: ASTM 976 and a method involving simultaneous equations relating the experimentally determined cetane numbers for several transesterified oils and the fatty acid compositions of the oils. Cetane indexes calculated according to ASTM 976 produced values which were too low for ester mixtures high in saturated acids and low in polyunsaturated acids, and were somewhat high for ester mixtures high in polyunsaturated acids. When cetane indexes calculated according to the simultaneous equation method were applied to the fatty acid mixtures, the agreement with those experimentally determined was approximately the error of determination of the cetane number.
Gossypol: High‐performance liquid chromatographic analysis and stability in various solvents
Authors: Nomeir A. A. , Abou‐Donia M. B.
Published: June 2007

An improved high performance liquid chromatography (HPLC) method of gossypol analysis was developed and compared with the current spectrophotometric method. Gossypol was determined in four samples of cottonseeds ofGossypium hirsutum with varying contents of gossypol, as well as in the stems and roots ofG. arboreum andG. thurber. The roots of both species each contained equally high amounts of gossypol, while the stems of each species varied in content. Those ofG. thurber contained slightly higher amounts of gossypol than those ofG. arboreum. Among the seeds studied, the glanded cottonseeds contained the highest concentration of gossypol, followed by low gossypol seeds, then glandless cottonseeds, and finally the roasted glandless cottonseeds. The stability of gossypol was studied in five solvents at six different storage temperatures. Both the type of solvent and the temperature were found to affect the rate of decomposition of gossypol. In all the solvents studied, gossypol was found to be highly unstable at 37 C and at room temperature, while its stability increased as the storage temperature decreased. At all temperatures, depending on the solvent used, the rate of decomposition increased in the following order: acetone < acetonitrile < chloroform < ethanol < methanol. Although the decomposition products of gossypol were not identified, their formation was found to be dependent on the solvent used.
Elimination of air and water pollution by double‐stage scrubber
Authors: Athanassiadis A.
Published: June 2007

This new scrubbing system has been developed to eliminate entirely air pollution caused by water cooling towers during oil or fat deodorization. It also minimizes water effluent. In industrial application for more than one year, this system is based on the action of two scrubbers placed in series. The first scrubber is a conventional one, whereas the second uses concentrated cooled brine circulating in closed circuit as the condensing medium. A thorough purification of water vapors is thus achieved before the volatiles from the deodorizer enter into the high vacuum bosters. As a practical result of this special scrubbing process, the condensing water of the barometric condensers can be entirely recycled and this water is cooled by means of clean water in a surface heat exchanger requiring minimum maintenance for cleaning.
Formulation of nondairy coffee whiteners with cottonseed protein isolates
Authors: Choi Y. R. , Lusas E. W. , Rhee K. C.
Published: June 2007

Nondairy coffee whiteners were prepared on a pilot scale using four different glandless cottonseed protein isolates prepared by different processes. Bulk density, whitening capacity, cream separation and oil retention capacity of the whiteners were compared to those formulated with sodium caseinate and a commercial whitener. Glandless cottonseed protein isolates, prepared by conventional and aqueous extraction processes, are poor ingredients for coffee whitener production, showing poor whitening capacity, separation of proteins through sedimentation and separation of fat as a cream layer in a mixture with aqueous coffee. Succinylated cottonseed proteins showed many markedly improved characteristics as coffee whiteners. Ca. 50% replacement of sodium caseinate with succinylated cottonseed protein isolate did not affect the quality of whiteners compared to that of 100% sodium caseinate‐based whitener.
Fluorocarbon‐hydrocarbon interactions in interfacial and micellar systems
Authors: Mukerjee P.
Published: June 2007

The interactions of fluorocarbons and hydrocarbons in liquid mixtures are known to be highly nonideal. Recent research has indicated that the unusual characteristics of such interactions have a significant influence on the behavior of many interfacial and micellar systems in which such interactions occur. Results from several different studies are presented. These involve (a) properties of partially fluorinated surfactants and lipids, including comments on the use of fluorine substituted groups as spectroscopic probes; (b) surface tensions of nonideal mixtures of liquid fluorocarbons and hydrocarbons and their interfacial tensions against water; (c) adsorptions of fluorocarbon and hydrocarbon surfactants to air/water, hexane/water, and perfluorohexane/water interfaces and a comparison of relative affinities; (d) formation of mixed micelles of fluorocarbon and hydrocarbon surfactants and evidence of partial miscibility of micelles; (e) comparison of adsorption of fluorocarbon and hydrocarbon surfactants to graphon; and (f) comparison of wetting of hydrocarbon‐like solids by aqueous solutions of fluorocarbon and hydrocarbon surfactants.
Action of chlorophylls on the stability of virgin olive oil
Authors: Gutiérrez‐Rosales Francisca , Garrido‐Fernández Juan , Gallardo‐Guerrero Lourdes , Gandul‐Rojas Beatriz , Minguez‐Mosquera M. Isabel
Published: June 2007

Virgin olive oil was used as substrate to study the influence of chlorophylls on its oxidative stability in light and in darkness. Chlorophylls a and b were added to this substrate, after which oils were stored at 36 ± 2°C for three months under artificial light (1340 lux) or in darkness. The effect of light was greater than that of the additives. The prooxidant action of chlorophylls in the presence of other pigments of the oil was not observed in this assay. During early storage, the rate of peroxide formation was lower in the samples with added chlorophylls, but later it equalled that of the control. In darkness, stability was greater in the samples containing chlorophylls, indicating a slight antioxidant effect, which was more marked for chlorophyll a.
Dielectric properties for monitoring the quality of heated oils
Authors: El‐Shami S. M. , Selim I. Zaki , El‐Anwar I. M. , El‐Mallah M. Hassan
Published: June 2007

Dielectric properties (dielectric constant ε′ and dielectric loss ε″) were compared to conventional methods of analysis (viscosity, refractive index, iodine value, peroxide value and free fatty acids) for evaluating the frying quality of a blend of cottonseed and sunflower oils. The apparent relaxation time, τ, the activation energy H and the entropy change S for dielectric relaxation of the heated oil samples were calculated. Results indicate that dielectric constant and dielectric loss are useful tools for predicting deterioration occurring during heating of the oil.
A new twin‐screw press design for oil extraction of dehulled sunflower seeds
Authors: Isobe S. , Zuber F. , Uemura K. , Noguchi A.
Published: June 2007

Transport of material in a single‐screw press depends mainly on friction between the material and the barrel’s inner surface and the screw surface during screw rotation. Thus, a solid core component, like seed hulls, is often necessary to produce the fraction. This sometimes causes excess frictional heat, large energy consumption and oil deterioration. Furthermore, if single‐screw presses are not configured with breaker bars or other special equipment, they provide inadequate crushing and mixing.

A twin‐screw oil press can be expected to solve these problems because of the higher transportation force, similar to a gear pump, and better mixing and crushing at the twin‐screw interface. A twin‐screw press (screw diameter=136 mm, length/diameter=6.5, screw speed 15–100 rpm, feed rate=50–150 kg/h) was designed with partially intermeshing and counter‐rotating screws and was tested on dehulled sunflower seed. The results were compared to a single‐screw lab‐scale press. Dehulled sun‐flower seed (wt, 6.0%; oil, 58.6%) without pretreatments (crushing or cooking) gave 93.6% oil recovery with the twin‐screw press, in contrast to 20% oil recovery with the single‐screw press. The oil expressed with a twin‐screw press had less foreign material than the oil from the single‐screw press. Other properties of the oil were also good. Energy consumption of the twin‐screw press was more efficient. All results suggested that oil production from dehulled sunflower seed with a twin‐screw press is highly efficient.
Removal of cellulose from sunflower meal by fractionation
Authors: Lević Jovanka , Delić I. , Ivić Mellta , Rac M. , Stefanović Sofija
Published: June 2007

The dependence of sunflower meal fractionation on the following factors was investigated: quality of original meals, 37.5%, 40.0% and 42.5% crude protein; screen hole size, 1.5 mm, 2.0 mm, 2.5 mm and 3.0 mm; and single‐phase and two‐phase fractionation. The following conclusions were drawn. The increased protein levels in original meals (from 37.5% to 42.5% crude protein) had considerably greater effects on the quality than on the yield of the protein fractions. Increased screen hole size (from 1.5 mm to 2.5 mm) increased the yield of the protein fractions by 16.4–22.3%, but reduced the protein level in these fractions by 2.3–2.8%. Two‐phase fractionation of the original meals with 40.0% and 42.5% crude protein increased the protein yield in the resulting protein fractions by 15.5–22.8%. The most efficient fractionation procedures rendered high yields of attractive protein fractions that contained 44.0–47.5% crude protein. The protein fractions were analyzed for physico‐functional constants and amino acid composition. The most efficient and applicable fractionation procedures, those that may be successfully used in oil refineries, were selected.
Adsorptive capacity of active filter aids for used cooking oil
Authors: Yates R. A. , Caldwell J. D.
Published: June 2007

Many materials are purported to adsorb polar compounds that are the result of degradation of oils used for deep‐fat frying. In the present study, the capacity of several of these adsorbents in terms of the amount of polar oil degradation compounds adsorbed by a given weight of material was determined. A significant difference in the adsorptive characteristics and capacity of the materials tested was demonstrated. Adsorptive capacity varied from 0 to over 150 mg of total polar compounds per gram of adsorbent. Some of the materials demonstrated selective adsorption characteristics. For these materials, only one class of polar compounds was adsorbed.
An overview of the phenolics of canola and rapeseed: Chemical, sensory and nutritional significance
Authors: Shahidi Fereidoon , Naczk Marian
Published: June 2007

Utilization of rapeseed meal in human foods has been thwarted by the presence of antinutritional factors such as glucosinolates, phenolics, phytates and hulls. The content of phenolics in rapeseed flour is nearly 30 times higher than that of soybean. Phenolic compounds contribute to the dark color, bitter taste and astringency of rapeseed meals. They may also interact with amino acids, enzymes and other food components, thus influencing the nutritional value of rapeseed meal and its products. Therefore, phenolic compounds are important factors when considering rapeseed meal as a protein source in food formulations. Available literature data on phenolic compounds and tannins of rapeseed/canola are fragmentary and diverse. Furthermore, developing a standardized method for analysis and quantitation of these compounds is warranted. Interaction of rapeseed phenolics/tannins with proteins and their effects on enzymes and other food components remain to be studied.
Digestibility of fatty acid monomers, dimers and polymers in the rat
Authors: Márquez‐Ruiz G. , Pérez‐Camino M. C. , Dobarganes M. C.
Published: June 2007

This study was designed to determine digestibilities of fatty acid monomers, dimers and polymers as components of diets containing thermally oxidized oils. Male Wistar rats were fed semipurified diets supplemented with unheated, heated and a 1:1 mixture of unheated/heated olive oils at 6, 12 and 20% w/w of diet. In a 14‐d experimental period, fecal lipids were extracted and analyzed by a combination of adsorption and high‐performance size‐exclusion chromatographies. Thus, it was possible to separate and quantitate five groups of fatty acids—nonpolar monomers, oxidized monomers, nonpolar dimers, oxidized dimers and polymers. Nonpolar fatty acid monomers showed high digestibilities, although significantly influenced by the alteration level of the dietary oil. The apparent absorption of oxidized fatty acid monomers averaged 76.6%. Among polymeric fatty acids, the lowest digestibilities were found for nonpolar dimers (10.9% on average), whereas oxidized dimers and polymers possessed higher apparent absorbability than expected, ranging from 22.7% to 49.6%. Chemical modifications prior to absorption, leading to less complex products, may have contributed to enhanced digestibility of polymers.
Chlorophyll adsorption on acid‐activated clay
Authors: Güler Çetin , Tunç Fatma
Published: June 2007

An acid‐activated clay (Çanakkale montmorillonite from Turkey) was used to adsorb chlorophyll from hexane solutions. The phenomenon seems to be mainly driven by the interaction of chlorophyll with acid sites. The adsorption of chlorophyll on Brönsted acid sites was indicated by a characteristic infrared band for the ‐OH group at 3671 cm−1. The variations in the structure of clay mineral and chlorophyll during adsorption have been examined by differential thermal analysis, thermogravimetry and infrared spectroscopy of the activated clay before and after adsorption of chlorophyll. Oxidation of adsorbed chlorophyll was completed at quite a high temperature.
Measurement of oxidation in dried milk products with thiobarbituric acid
Authors: Sidwell C. G. , Salwin Harold , Mitchell J. H.
Published: June 2007

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.