Hydrocarbons and other weakly polar unsaponifiables in some vegetable oils

The hydrocarbon fractions obtained from sunflower, olive, soybean, rapeseed and pumpkin seed oils by fractionation of unsaponifiable matter were composed of n-paraffins, isoprenoidal polyolefins, squalene, diterpene and triterpene hydrocarbons and compounds with oxygen. Iso-, anteiso- and other branched hydrocarbons were not identified in any of investigated oils. Possible compounds with oxygen are aliphatic and alicyclic ketones, conjugated steroid ketones, esters and lactones. The differences in the hydrocarbon fractions of investigated oils suggest they may be used for characterization.     

Characterization of triterpene alcohols of seed oils from some species of theaceae,phytolaccaceae and sapotaceae

Triterpene alcohol constituents of the unsaponifiable lipids separated from tea seed oil fromThea sinensis L. (Theaceae), camellia seed oil fromCamellia japonica L. (Theaceae), pokeweed seed oil fromPhytolacca americana L. (Phytolaccaceae) and shea butter from the seed kernels ofButyrospermum parkii (Sapotaceae) were studied. Among a number of triterpene alcohols present in these oils, 19 components were identified as cycloartenol, 24-methylenecycloartanol, parkeol, 24-methylene-24-dihydroparkeol, lanosterol, euphol, butyrospermol, tirucallol, tirucalla-7,24-dienol, dammaradienol, 24-methylenedammarenol, α-amyrin, β-amyrin, lupeol, germanicol, taraxasterol, ψ-taraxasterol, taraxerol and myricadiol. Tirucalla-7,24-dienol and butyrospermol are the predominant components of the 2 Theaceae and pokeweed seed oils. Shea butter, on the other hand, contains α-amyrin followed by butyrospermol and lupeol as the major triterpene constituents. Presented at the AOCS Annual Meeting, San Francisco, April/May 1979.     

Triterpene alcohols and sterols of vegetable oils

Triterpene alcohols and sterols were separated by thin-layer chromatography and gas-liquid chromatography from the unsaponifiable fractions of the following 18 vegetable oils: linseed, peanut, olive, rice bran, palm kernel, corn, sesame, oiticica, palm, coconut, rapeseed, grape seed, sunflower, poppy seed, castor, tea seed, cocoa butter and soybean. Two triterpene alcohols, cycloartenol and 24-methylene cycloartanol, were found in all of the oils except soybean oil, which contained only cycloartenol. Triterpene alcohols such as α- and β-amyrin, euphorbol, butyrospermol and cyclolaudenol also were encountered occasionally. Three sterols, β-sitosterol, stigmasterol and campesterol were present in all of the oils. In addition a fourth sterol, not yet idenfified, was found in oils of palm, palm kernel and sunflower in varying amounts. This unknown sterol and brassicasterol were found in rapeseed oil in addition to the three sterols that were common to all of the oils studied. Experiment Station for Fats and Oils, National Center for Lipochemistry of National Research Council, Milan, Italy.     

Acyclic and incompletely cyclized triterpene alcohols in the seed oils of theaceae and Gramineae

The triterpene alcohol constituents of the non-saponifiable lipids of two Theaceae seed oils, sasanqua and camellia oils, and two Gramineae seed oils, wheat germ and rice bran oils, were investigated. This led to the isolation and characterization of one acyclic and eight incompletely cyclized triterpene alcohols. They are camelliol A, camelliol B, camelliol C, achilleol A, helianol, isohelianol, sasanquol, graminol A [(13R, 14R)-3,4-seco-25(10→9)abeo-8α,9β,10α-podioda-4,17,21-trien-3-ol], and (2Z,6Z,10Z,14E,18E)-farnesylfarnesol. Two other compounds isolated were characterized as (2Z,6Z,10E,14E)-geranylfarnesol, a sesterterpene alcohol, and phytol, a diterpene alcohol. Graminol A and (2Z,6Z,10E,14E)-geranylfarnesol are considered to be new natural products. Based on a paper presented at the symposium, “Chemistry, Biochemistry, and Function of Sterols,” AOCS Annual Meeting & Expo, Orlando, FL, May 1999.     

Molecular distillation of some Indian vegetable oils

Summary 1. Karanja, malkanguni, undi, and sesame oils were molecularly distilled, and the fractions obtained were characterized for their physical and chemical constants. 2. Generally, the first few fractions were found to be rich in odor, free fatty acids, and unsaponifiable matter. 3. Sesamin could be isolated from the first fraction of molecularly distilled sesame oil by crystallization. 4. Karanjin and pongamol were similarly separated from the first fraction of molecularly distilled karanja oil. 5. With malkanguni oil there was some fractionation of the glycerides. 6. Elimination curves of karanja, malkanguni, undi, and sesame oils are given.     

4-demethyl-,4-monomethyl-and 4,4-dimethylsterols in some vegetable oils

The content of 4-demethyl-, 4-monomethyl- and 4,4-dimethylsterols in 13 vegetable oils was found to vary between 0.10–1.4%, 0.01–0.08% and 0.02–0.29%, respectively. The largest amount of demethylsterols was found in maize and wheat germ oils, whereas the largest amounts of the dimethylsterols were found in olive and linseed oils. The predominating demethylsterols were sitosterol, campesterol, stigmasterol and Δ⁵-avenasterol. Among the 4-monomethylsterols, obtusifoliol, gramisterol, cycloeucalenol and citrostadienol predominated, but usually more than 10 components were found in this fraction. The composition of the 4,4-dimethylsterol fraction was also rather complex, with the 9,19-cyclopropanesterols together with α- and β-amyrin predominating. In most of the oils, characteristically high or low percentages of some sterols were found, and a few specific sterols were also noted. A scheme useful for characterization is presented.     

Pancreatic lipolysis of some brominated vegetable oils

Pancreatic lipolysis of several commercially used brominated vegetable oils has shown that although hydrolysis proceeds more slowly, these oils are degraded in a similar way to the common vegetable oils.     

Ultrasonic velocity measurements in some liquid triglycerides and vegetable oils

A pulse echo technique was used to measure the ultrasonic velocity of nine vegetable oils (5–70 C, 1.25 MHz) and a number of liquid triglycerides and triglyceride/sunflower oil mixtures (70 C, 1.25 MHz). The velocities of the vegetable oils at 70 C were related to the velocities of their constituent components using two empirical equations; the first related the velocity of a triglyceride to its molecular formula, and the second related the velocity of an oil to the velocities of its triglyceride components.     

Pro-oxidant effect of some carbonyl compounds in vegetable oils

Certain carbonyl compounds comparable in structure to those which might be produced in browning degradations of sugars were found to act as pro-oxidants in vegetable oils. Action of these compounds as pro-oxidants was apparent in oils held at 57C in open beakers, but not in oils at 99C in the AOM test. Presented at the AOCS Meeting in Minneapolis, 1963. General Mills Central Research Journal Series, Paper No. 353.     

Sterols,methyl sterols,triterpene alcohols and fatty acids of the kernel fat of different malagasy mango(Mangifera indica) varieties

The kernel fat content of 16 different mango varieties collected from the Northwestern part of Madagascar island were examined. The fat content (22–54%) was determined by chloroform/methanol extraction. Investigation by gas liquid chromatography (GLC) revealed 15 fatty acids, mainly palmitic (7–12%), stearic (22–40%), oleic (41–48%) and linoleic (7–17%). Significant correlations were observed among the main fatty acids. Testing for the sterol fraction in 15 mango varieties allowed us to separate and quantitatively analyze 7 sterols by GLC. The main sterols wereβ-sitosterol (47–76%), stigmasterol (12–23%) and campesterol (7–12%). The stigmasterol/campesterol ratio (1.2:2.3) was lower in mango kernel fat than in cocoa butter. Among the 4-methyl sterol fractions, gramisterol, lophenol, obtusifoliol and citrostadienol were tentatively identified by GLC. Lupeol, cycloartenol,α- andβ-amyrins and friedelinol were tentatively identified by GLC in the triterpene alcohols fractions.     

Kinetics of catalytic transfer hydrogenation of some vegetable oils

Catalytic transfer hydrogenation of corn, peanut, olive, soybean, and sunflower oils has been studied with aqueous sodium formate solution as hydrogen donor and palladium on carbon as catalyst. Kinetic constants and selectivity have been determined under intensive stirring in the presence of stabilizing agents. Hydrogenation reactions followed first-order kinetics with respect to fatty acids. Besides good selectivity and short reaction time, this method offers safe and easy handling. The presence of linolenic acid retards the migration of double bonds, which explains why soybean oil is the most appropriate for this hydrogenation process.     

Phytosterols,triterpene alcohols,and phospholipids in seed oil from white lupin

This study was conducted to determine effects of genotypes and growing environment on phytosterols, triterpene alcohols, and phospholipids (PL) in lupin (Lupinus albus L.) oil from seven genotypes grown in Maine and Virginia. The unsaponifiable lipid (UNSAP) and phospholipid (PL) fractions ranged from 2.1 to 2.8% and from 2.6 to 2.8% of oil, respectively. UNSAP in lupin oil contained 19.9 to 28.7% sterols and 17.3 to 22.0% triterpene alcohols. Growing location significantly affected contents of total PL, PS, phosphatidylglycerol, β-sitosterol, campesterol, and β-amyrin. Genotypic effects were significant for stigmasterol. PC (32.6 to 46.3% of PL), PE (21.6 to 32% of PL), and PS (11.2 to 17.9% of PL) were the major PL in lupin oil. The concentration of PL classes in lupin oil were in the following descending order: PC>PE>PS>PI>phosphatidic acid > lysophosphatidylcholine > phosphatidylglycerol > diphosphatidylglycerol. In descending order of abundance, the sterols present in lupin oil were: β-sitosterol > campesterol > stigmasterol > Δ⁵-avenasterol > Δ⁷-stigmastenol Lupeol was the most prominent triterpene alcohol in lupin seed oil. In general, growing environment had a much greater influence on lupin oil characteristics than the genotypes.     

Pristane and other hydrocarbons in some freshwater and marine fish oils

Pristane levels in four commercial freshwater fish oils (alewife, tullibee, maria and sheepshead) were found to be markedly lower (0.0001% or less) than those in marine fish oils (herring, sand launce, cod liver and gray cod liver) selected for comparison on the basis of similar types of depot fat storage (0.008–0.107%). Certain normal alkanes were also identified by gas chromatography. Of these, heptadecane was predominant in all of the freshwater fish oils, but octadecane was more prevalent than heptadecane in three of the marine oils.     

Viscosity estimation of triacylglycerols and of some vegetable oils, based on their triacylglycerol composition

The experimentally determined kinematic viscosities of simple triacylglycerols [trilaurin, trimyristin (MMM), tripalmitin (PPP), tristearin (SSS), triolein (OOO), and trilinolein (LiLiLi) were correlated to a modified Andrade-type equation. The constants for the modified equation were derived for each simple triacylglycerol. The method was also used to estimate the viscosity of mixed triacylglycerols [1,2-dimyristoyl-3-palmitoyl (MMP), 1,2-dioleoyl-3-palmitoyl (OOP), 1,2-dimyristoyl-3-oleoyl (MMO), and 1,2-dipalmitoyl-3-oleoyl (PPO)], binary triacylglycerol mixtures (PPO/OOP, PPP/SSS, and OOO/SSS of different portions), and three types of vegetable oils [refined, bleached, and deodorized palm oil; cocoa butter; and canola oil] by applying modified Kay’s rule utilizing the simple triacylglycerol constants derived earlier. In all cases, the estimated values for liquid viscosity were compared with experimental values determined in this work and with previous work from the literature. When applied to vegetable oils, the method requires knowledge of their triacylglycerol composition. Despite its simplicity, the method gives a reasonable estimate. The method may be used to predict the viscosity of different blends of vegetable oils, and the accuracy is expected to increase when more experimental data on simple triacylglycerols become available.     

The specific and latent heats of fusion of some vegetable fats and oils

Summary The specific heats of several vegetable oils have been determined by a more exact procedure than those which seem to have been used heretofore. Values slightly higher than the literature figures were obtained, that is, an average value of 0.53 was determined as compared to reported results of 0.50. The specific heat of cottonseed oil with respect to temperature increases slightly with elevating temperatures. The specific heats at different temperatures were not determined on the other oils, but likewise, these probably show no significant variation in specific heat with respect to temperature in the range 21° to 100°C. The specific heats of completely solid vegetable fats are believed to be reported for the first time. These values are about the same for such different stocks as completely hardened palm and sunflower oils, and their values are approximately one-half that of the liquid, that is, 0.28 as compared to 0.53. The latent heats of fusion of a number of fats have also been determined by what is thought to be a satisfactory procedure. Theoretical aspects and empirical results are given to show that the latent heat of fusion varies with the temperature when two phases are present, and that for this reason, any references to the latent heat of fusion should be accompanied by temperature limitations. This is not so important, however, when the specimen is completely solid at the temperature in question. The data and graphs presented show the general variation in latent heat of hardened cottonseed oil at one temperature with respect to iodine value.     

Studies on phytosterol oxides. II: Content in some vegetable oils and in French fries prepared in these oils

Hydrogenated rapeseed oil/palm oil blend, sunflower oil and high-oleic sunflower oil, and French fries fried in these oils were assessed for contents of sterol oxidation products. Different oxidation products of phytosterols (7α- and 7β-hydroxy-sito-and campesterol, 7-ketosito- and 7-ketocampesterol, 5α,6α-epoxy-sito- and campesterol, 5β,6β-epoxy-sito-and campesterol, dihydroxysitosterol and dihydroxycampesterol) were identified and quantiated by gas chromatography (GC) and GC-mass spectroscopy. Rapeseed oil/palm oil blend contained 41 ppm total sterol oxides before frying operations. After two days of frying, this level was increased to 60 ppm. Sunflower oil and high-oleic sunflower oil had 40 and 46 ppm sterol oxides, respectively, before frying operations. After two days of frying operations, these levels increased to 57 and 56 ppm, respectively. In addition to campesterol and sitosterol oxidation products, small amounts of 7α- and 7β-hydroxystigmasterol were detected in the oil samples. Total sterol oxides in the lipids of French fries fried at 200°C in rapeseed oil/palm oil blend, sunflower oil, and high-oleic sunflower oil were 32, 37, and 54 ppm, respectively. The levels of total oxidized sterols, calculated per g sample, ranged from 2.4 to 4.0 ppm. In addition to the content of phytosterol oxides, full scan mass spectra of several oxidation products of stigmasterol are reported for the first time. Part of these results were presented at the 86th Annual Meeting of the AOCS, May 7–11, 1995, San Antonio, TX.     

Free primary alcohols in oils and waxes from germs,kernels and other components of nuts,seeds, fruits and cereals

The composition of free primary alcohols in oils and waxes obtained from the germ, kernel, seed coat, shell and skin (peel) of various nuts, seeds, fruits and cereals and from the chrysalis of silkworm was examined. These alcohols are usually present in small amounts, along with large quantities of hydrocarbons, esters and glycerides in oils and waxes. Thus, it is necessary to remove hydrocarbons, esters and glycerides to analyze the alcohols. We found that preparative reverse-phase thin-layer chromatography (TLC) was the best way to isolate alcohols from oils and waxes. Gas liquid chromatography (GLC) then detected hexacosanol, octacosanol and triacontanol in the oils and waxes. Octacosanol usually was the predominant alcohol. Relationships between the organs from nuts, seeds, fruits and cereals and the contents of octacosanol are suggested. For example, degermed kernels contained two times more octacosanol than the germ, and the skin coat and shell contained one-half and one-fortieth the octacosanol of the germ, respectively.