Glyceride Molecules Research Articles

Lipidomics reveals lipid changes in the intramuscular fat of geese at different growth stages

The quality (color, tenderness, juiciness, protein content, and fat content) of poultry meat is closely linked to age, with older birds typically exhibiting increased intramuscular fat (IMF) deposition. However, specific lipid metabolic pathways involved in IMF deposition remain unknown. To elucidate the mechanisms underlying lipid changes, we conducted a study using meat geese at 2 distinct growth stages (70 and 300 d). Our findings regarding the approximate composition of the meat revealed that as the geese aged 300 d, their meat acquired a chewier texture and displayed higher levels of IMF. Liquid chromatography-mass spectrometry (LC-MS) was employed for lipid profiling of the IMF. Using a lipid database, we identified 849 lipids in the pectoralis muscle of geese. Principal component analysis and orthogonal partial least squares discriminant analysis were used to distinguish between the 2 age groups and identify differential lipid metabolites. As expected, we observed significant changes in 107 lipids, including triglycerides, diglycerides, phosphatidylethanolamine, alkyl-glycerophosphoethanolamine, alkenyl-glycerophosphoethanolamine, phosphatidylcholine, phosphatidylinositol, lysophosphatidylserine, ceramide-AP, ceramide-AS, free fatty acids, cholesterol lipids, and N-acyl-lysophosphatidylethanolamine. Among these, the glyceride molecules exhibited the most pronounced changes and played a pivotal role in IMF deposition. Additionally, increased concentration of phospholipid molecules was observed in breast muscle at 70 d. Unsaturated fatty acids attached to lipid side chain sites enrich the nutritional value of goose meat. Notably, C16:0 and C18:0 were particularly abundant in the 70-day-old goose meat. Pathway analysis demonstrated that glycerophospholipid and glyceride metabolism were the pathways most significantly associated with lipid changes during goose growth, underscoring their crucial role in lipid metabolism in goose meat. In conclusion, this work provides an up-to-date study on the lipid composition and metabolic pathways of goose meat and may provide a theoretical basis for elucidating the nutritional value of goose meat at different growth stages.

Dimethyl carbonate mediated production of biodiesel at different reaction temperatures

Methanol was replaced by dimethyl carbonate for biodiesel production. In the process, fatty acid methyl ester (FAME) was produced through transesterification of soybean oil with dimethyl carbonate (DMC) using potassium methoxide as a catalyst. This method produced a more attractive by-product, glycerol carbonate (GC). Factors affecting the reaction such as vegetable oil to DMC molar ratio, catalyst concentration, reaction time and reaction temperature were optimized. Triglyceride conversion of 95.8% was obtained at the optimized condition. This process provided an insight into the reactivity of DMC at different temperature. Co-production of FAME and glycerol carbonate (GC) proceeded through carboxymethylation reaction because methoxyl group and carbonyl group are generated which subsequently attacked the carbonyl moiety in glyceride molecules to form the required products.

Maleinization of Soybean Oil Glycerides Obtained from Biodiesel‐Derived Crude Glycerol

AbstractGlycerides obtained from the glycerolysis of soybean oil with crude glycerol were acylated with maleic anhydride at 80–100 °C. Both uncatalyzed and catalyzed reactions with 2‐methylimidazole (2‐MI) were evaluated. Formation of maleated glycerides was confirmed by 1H‐NMR and FTIR analyses. Consumption of maleic anhydride as a function of time was followed by acid value titration. High conversion (ca. 95 %) of hydroxyl groups was obtained at 90 °C in 60 min without catalyst. Under these conditions, a product with 1.9 maleate moieties per glyceride molecule was obtained. Catalyzed reactions afforded lower conversions of hydroxyl groups and lower maleate yields compared to uncatalyzed reactions.

Synthesis of maleated-castor oil glycerides from biodiesel-derived crude glycerol

Castor oil glycerides were obtained from the glycerolysis of castor oil or its methyl esters with alkaline-crude glycerol. High monoglyceride yields were obtained between 20–30min and 180–200̊C with both substrates. The glycerolysis of castor oil afforded highest yield of products at 180̊C and 30min (50.4 of monoglycerides and 35% of diglycerides). However, the glycerolysis of methyl esters was more selective toward the formation of monoglycerides. Castor oil glycerides were further esterified with maleic anhydride without catalyst. Reaction was followed by acid value and 1H NMR. ca. 87% conversion of hydroxyl groups was obtained at 90̊C. The final product contained 2.6 maleate groups per glyceride molecule.

Thermal degradation and isomerisation kinetics of triolein studied by infrared spectrometry and GC–MS combined with chemometrics

Triolein, a triglyceride containing oleic acid as the only acid moiety in the glyceride molecules has been isothermally treated at 280, 300, and 325 °C in glass vials under nitrogen atmosphere. The products formed during the thermal treatment at each temperature have been analysed both by infrared spectrometry and GC–MS. The GC–MS analysis was performed after derivatisation of the fatty acids into their methyl esters (FAMEs). Chemometric tools were used in determining the concentrations of the main products namely triolein and trieaidin in the thermally treated mixtures. The concentration profiles of the trielaidin formed during thermal treatment at the above three temperatures were used in determining activation energy for the cis– trans isomerisation of triolein. The combined analysis reveals that the thermal treatment induces not only cis– trans isomerisation but also fission and fusion in the molecules. Furthermore, migration of the double bond in oleic and elaidic acids forming cis and trans isomers of the 18:1 acid was also observed. The heat-induced isomerisation in triolein follows a zeroth order reaction with an activation energy 41 ± 5 kcal/mol.

Molecular dynamics simulations to aid the rational design of organic friction modifiers

Molecular dynamics simulations were performed under conditions of constant volume and temperature and of constant pressure and temperature to elucidate the structure activity relationships of a series of non-ionic surfactant molecules derived from vegetable fat and employed as friction modifiers in commercial engine oils. The simulations show the extent to which intermolecular hydrogen bonding is important in determining the stability of the monolayer formed by the surfactant molecules and show that mono-alkanoyl glyceride molecules are able to pack more efficiently, forming significantly more intermolecular hydrogen bonds and occupying approximately half the volume needed by di-alkanoyl glyceride molecules. Density profiles are presented which show significant mixing of the hydrophobic tail groups and a non-polar solvent. The distribution of torsion angles in the tail groups shows that the conformation is consistent with a liquid at finite temperature rather than a crystal structure. The measured friction coefficients of equimolar solutions of the glycerides show that the efficacy as friction modifiers varies in the order mono-, di- and the tri-oleyl glyceride, which is consistent with the efficacy of film formation predicted by the molecular dynamics calculations.

Synthesis of structured lipids and etherlipids with antioxidants: combination of a selena fatty acid and a selena fatty alcohol with a carotenoic acid in glyceride molecules

Selenium and carotenoids show similar and complementary properties and protect against a variety of pathological processes. Mixtures of both compounds are found in nutritional supplements and are used to prevent several diseases. The synthetic connection of carotenoids with selenium in glycerols may increase the chemopreventive activity of the individual compounds. β-Apo-8′-carotenoic acid and 7-selenacapryloic acid were esterified with glycerol to highly unsaturated stable di- and triglycerides. Intramolecular selenium:carotenoid ratios of 1:1, 2:1 and 1:2 were obtained for 1-(7-selenaoctanoyl)-3-(β-apo-8¢-carotenoyl)-glycerol, 1,3-di-(β-apo-8′-carotenoyl)-2-(7-selenaoctanoyl)-glycerol and 1,2-di-(7-selenaoctanoyl)-3-(β-apo-8′-carotenoyl)-glycerol, respectively. The carotenoic acid was likewise connected to the pharmacologically interesting 11-selenalaurylglycerolether forming an alkyl-acylglyceride: 1-(11-selenadodecyl)-3-(β-apo-8′-carotenoyl)-glycerol.

Polymorphic stability of some shortenings as influenced by the fatty acid and glyceride composition of the solid phase

A number of North American vegetable and animal fat shortenings, which had been analyzed previously for their physical and textural characteristics, were analyzed also for their chemical composition. The fatty acid and triglyceride composition of the solids were calculated by analyzing the composition of the original product and the liquid phase, and by determination of the solid fat content (SFC) of the fat. The solids were also isolated by isopropanol (IP) separation, and the high melting glycerides (HMG) by acetone crystallization at 15°C. There was not much difference in total saturates andtrans content between vegetable and animal fat shortenings. Changing formulations from soy‐palm to soy‐cottonseed does not change the total saturates plustrans content. The solids of the vegetable shortenings in the β form contained about 20% of 16:0, those in the β′ form 30% or more. The animal fat shortenings were mainly in the β form, their solids contained 30% or more of 16:0. C54 triglyceride content of the solids of β vegetable shortenings (calculated and IP‐separated) was >45%, that of all animal fats was <25%. Solids of animal fat shortenings contain high levels of C52. The C54 triglycerides are β‐tending and should be kept low in vegetable shortening. In the HMG the C54 should not exceed 30%. This can only be achieved by incorporation of a β′ hard fat, preferably palm hard fat. Animal fat, especially lard, crystallizes in the β form because the palmitic acid in the glyceride molecule is located in the 2‐position, whereas those of vegetable fats are in the 1‐ and 3‐position.

Effect of cholesterol on structural and dynamic properties of tripalmitoyl glyceride. A high-pressure infrared spectroscopic study

The infrared spectra of tripalmitoyl glyceride confirm the tuning fork configuration previously attributed to trilauroyl glyceride (Small, D. M. 1986. Handbook of Lipid Research. Vol. 4). The acyl chains in solid tripalmitoyl glycerol, either within each molecule or between neighboring molecules, are oriented parallel to each other with the sn-3 acyl chains extended toward the opposite direction of the sn-1 and sn-2 chains. The presence of cholesterol increases the orientational disorder of the tripalmitoyl glyceride molecules in terms of increased reorientational fluctuations and twisting/torsion motions of the acyl chains. In the solid mixture, cholesterol is embedded in the tripalmitoyl glyceride lattice which results in a reorientation of the acyl chains within each molecule from a parallel packing to a nonparallel packing. No evidence was found for hydrogen bond formation between the OH group of cholesterol and any of the three C = O groups of tripalmitoyl glyceride.

Effect of Interesterified Fats and Isolated trans Fatty Acids on Serum Lipid Classes in Cholesterol‐Bile Salt Stressed Rats

AbstractInteresterified plastic fat products based on a) sal fat and groundnut oil (30: 70, w/w;P/S,0.8) (sal‐GNO);b) vanaspati, partially hydrogenated vegetable oil and groundnut oil (40:60; P/S, 1.0; isolated trans fatty acid content 17%) (vanaspati‐GNO);c) cottonseed oil (P/S, 1.5) (CSO) and d) sal fat and safflower oil (50:50, P/S, 1.3) (sal‐saff) were prepared using dry sodium methoxide as the catalyst. The products had slip points of 33−34°C. These products, their original blends, safflower oil (P/S, 8.5) and a blend of vanaspati and safflower oil (50 : 50, P/S, 2.8 and isolated trans fatty acid content 22%) (vanaspati‐saff) were tested for hypolipidaemic effect (serum total cholesterol, total lipids, triglycerides and phospholipids) in cholesterol‐bile salt stressed rats. All the test fats having linoleic acid content varying from 21.9‐76.6% and P/S ratio from 0.8 to 8.5 and fed at 10% level providing 23% calorie were found to be superior to vanaspati (P/S, 0.16, 3% linoleic, 43% isolated trans fatty acids). P/S ratio of 1.5 and linoleic content of 30% in fat were found to be optimum for maximum hypolipidaemic effect at above dietary regimen. Fat and cholesterol contents of liver of animals, fed test lipids were significantly lower than that of animals fed vanaspati. when linoleic acid content of the product was comparatively low (e.g. sal‐GNO, 25%), the process of rearrangement reduced the cholesterol content of liver. With high linoleic acid content (CSO, 48.2% or sal‐saff, 40.4%) interesterification was without any effect. Hypolipidaemic effect of interesterified products was similar to that observed with original materials. Thus, the above quality of a fat having characteristics within the above ranges does not depend upon the distribution of acyl groups in glyceride molecules. Isolated trans fatty acids behaved more or less like a saturated fatty acid in elevating serum lipids. Vanaspati was found to be highly hyperlipidaemic.

Interfacial structure and lipase action. Characterization of taurodeoxycholate-didecanoylglycerol monolayers by physical and kinetic methods.

Surface pressure-area isotherms for 1,3-didecanoyl-glycerol (dicaprin) were determined as a function of the concentration of taurodeoxycholate in the subphase. Analysis of these curves indicates that, from 0.05 to 0.80 mM bile salt, surface structure is dependent only on the surface concentration of the diglyceride. The limiting areas for dicaprin in the presence and absence of bile salt were about 38 A2/molecule. Subjecting the monolayers to hydrolysis by pancreatic lipase yielded kinetic data which, together with the physical studies, support a model for monolayer glyceride molecules undergoing discrete changes of state. In the absence of bile salt, the relatively expanded state exhibits an area of 75 A2/diglyceride molecule and is not a substrate for pancreatic lipase B. The more condensed state exhibits an area of 38 A2/diglyceride molecule and is hydrolyzed at a rate proportional to its concentration in the monolayer. Taurodeoxybholate at 0.05 to 0.60 mM shifts the apparent area of the expanded state to 360 A2/diglyceride molecule.

Enzymatic reactions on thin-layer chromatographic plates : I. Lipolysis of triglycerides and separation of products on a single plate

A novel method for the lipase deacylation of triglycerides is described in which 0.1–0.2 ml of the enzyme solution in 1 M tris buffer (pH 8.2) containing 2–4 mg of protein is applied as a band on a 0.5-mm thick silica gel thin-layer chromatographic plate. Over this band, 1–4 mg of triglyceride in n-hexane is applied evenly and the plate is incubated at 40° for 1–2 min. The reaction is stopped by exposure to hydrogen-chloride vapour and the products are removed from the reaction zone by three consecutive developments in diethyl ether up to 2 cm from the line of application. These are resolved by re-developing the plate in n-hexane—diethyl ether—acetic acid (80:20:1.5) up to 14 cm. The sn-2-monoglyceride and sn-1,2(2,3)-diglyceride bands located by iodine vapour are extracted and the fatty acid compositions evaluated by gas-liquid chromatography for the determination of fatty acid distribution in the glyceride molecule. The method, when applied to groundnut oil, goat depot fat, body fat of shol fish ( Channa striatus) and yeast ( Rhodotorula glutinis) fat, produced representative sn-1,2(2,3)-diglycerides which can be used for the stereospecific analysis of triglyceride.

The position of cyclopropenoid acids in a glyceride molecule

The position of cyclopropenoid acids in a glyceride molecule

Studies in Acidolysis

AbstractAcidolysis of a natural triglyceride oil with free fatty acids of different chain length has been studied to find out the degree of interchange of fatty acids, the mode of distribution of the free acids incorporated in the triglyceride molecules and the glyceride composition of the oil after acidolysis. The results as determined by gas‐liquid chromatography and pancreatic lipase hydrolysis indicate that the degree of interchange of fatty acids depends on the chain length of the free acids, and the incorporation of the free acids in the glyceride molecules occurs in a purely random manner. Glyceride compositions of the oils are also randomly rearranged after acidolysis reaction.

Studies on the Hydrogenation of Edible Oils. I.

In a continuation of the studies of this series, two hydrogenation runs of a cottonseed oil (I.V. 109.8) were conducted with a commercial nickel catalyst under different conditions, one under selective (0.2% catalyst, 180°C, 1.0kg/cm2, 200rpm) and the other under non-selective (0.1% catalyst, 150°C, 3.0kg/cm2, 500rpm) conditions. The hydrogenation was continued until the iodine value has fallen into 50 approx. Five samples of hydrogenated oils were taken at different stages of hydrogenation, the iodine values of the corresponding samples being approximately same for both runs. Each sample was analyzed with respect to softening point, S.F.I., trans-isomer (%) and fatty acid composition. Each of hydrogenated samples and the original cottonseed oil was separated by argentation-TLC into 5 to 8 fractions. From the yield and fatty acid composition of each fraction, the proportions of ten glyceride types, i.e., G-000, G-001, G-011, G-002, G-111, G-012, G-112, G-022, G-122 and G-222 were calculated. Further, each sample was subjected to permanganate-periodate oxidation, and the resulting azelao-glycerides, as their methyl esters, were analyzed by GLC.Results of the experiments indicate that monoene-rich glycerides are predominantly formed in the selective hydrogenation, whereas relatively large amounts of fully saturated glycerides are formed in the non-selective hydrogenation. The slope of S.F.I.-curves for non-selectively hydrogenated samples is generally more gentle than that for selectively hydrogenated samples. The GLC-chart of the methyl esters of azelao-glycerides from the original cottonseed oil is well defined, but the charts from hydrogenated samples, especially those from selectively hydrogenated samples, show many unknown peaks besides those corresponding to known azelao-glyceride esters, presumably due to double bond migration during hydrogenation. As in the case with olive oil reported in the preceding paper of this series, it is postulated also in the case of cottonseed oil that in the selective hydrogenation the more unsaturated glyceride molecules are hydrogenated in preference to the less unsaturated glyceride molecules, whereas in the non-selective hydrogenation the double bonds remaining in the glyceride molecules once adsorbed on the calalyst surface are likely to be hydrogenated in some preference to the unsaturated fatty acid groups of other glyceride molecules.

Gas-liquid chromatographic fractionation of natural diglycerides on organosilicone-polyester liquid phases.

Synthetic and naturally occurring diglyceride mixtures were successfully resolved according to their carbon number and degree of unsaturation by gas chromatography on organosilicone-polyester (EGSS-X, ECNSS-M) packings containing low loads of liquid phase. The diglycerides were chromatographed as the trimethylsilyl ethers and acetates. Complete separations and apparently quantitative recoveries were achieved with both types of derivatives within 20–60 min isothermally at 250–270 °C for most diglycerides of the common fatty acids containing 0–6 double bonds per glyceride molecule. The retention times of the acetates were longer than those of the corresponding trimethylsilyl ethers by a period of time equivalent to about four methylene units. The 1,2(2,3)-diglycerides were eluted ahead of the 1,3-diglycerides of comparable molecular weight, unsaturation, and positional distribution of fatty acids.

Hypocholesterolaemic effect of animal and plant fats in rats

Triglvcerides, containing approximately the same amounts of essential fatty acids (EFA) but differing in the positions of esterified EFA, were preparedfrom soy bean oil and lard, and were administered to male rats. After 6 weeks of feeding, weanling rats on either 1 or 5% (w/w) of lard fat had a higher plasma cholesterol level than animals on the corresponding levels of fat from soy bean oil. Similar results were obtained when cholesterol (1%) and cholic acid (0.25%) were included together in the diets. The plasma cholesterol level in rats fed 5% fat of soya source was lower than that in EFA deficiency. Hepatic cholesterol was strikingly elevated after the rats had been fed lard fat and cholesterol plus cholic acid compared with fat from soy bean oil and cholesterol plus cholic acid. When these fats were fed at the 10% level to mature rats for 2 weeks, the plasma cholesterol level in animals fed lard fat with cholesterol plus cholic acid was slightly higher than that in rats given the vegetable fat. The results suggest that differences in the positional distribution of EFA in the glyceride molecule may be responsible for the different concentrations of cholesterol induced by the two fats tested. Thus, EFA at the 1 and 3 positions in triglycerides may have less hypocholesterolaemic action than EFA at the 2 position.

Enzymatic Alkylenation of Phospholipid Fatty Acid Chains by Extracts of Mycobacterium phlei

Abstract The enzymatic synthesis of tuberculostearic acid (10-methylstearic acid) was catalyzed by extracts of Mycobacterium phlei. This process involved two reactions of the olefinic fatty acid chain of phospholipids. The chain was first alkylenated at the 10-carbon to give a methylene group, which was subsequently reduced to a methyl group. The first reaction could be measured by using S-adenosylmethionine-methyl-14C. The enzyme was found in the supernatant fraction when extracts of cells broken by sonic oscillation were subjected to centrifugation at 100,000 x g. S-Adenosyl-l-methionine was the only effective donor of the 1-carbon unit. Phosphatidylglycerol, phosphatidylinositol, and phosphatidylethanolamine were substrates for the reaction, and both 16- and 18-carbon chains were alkylenated although only the Δ9-olefinic chains appeared to be converted. The enzyme acted upon chains at either position 1 or 2 of the glyceride molecule. Several detergents had little effect on the rate of the reaction.

The digestibility of fats differing in glyceride structure and their effects on growth performance and carcass composition of bacon pigs

SUMMARYThe digestibility of fats differing in glyceride structure has been investigated, the fats used being natural lard, interesterified lard and beef tallow. Natural lard was found to be better digested than interesterified lard which in turn was better digested than beef tallow, the differences being the result of differences in the digestibility of the saturated fatty acids. The digestibility of palmitic acid was found to be dependent upon its positioning within the glyceride molecule, absorption being greatest when it was esterified in the β-position. The positional distribution of stearic acid was thought not to be the factor limiting the extent of its absorption in the given circumstances. The fats did not differ in their effects upon growth performance or carcass composition and differences in the digestibility of the fats were not reflected in the quality of the carcass backfat. It was demonstrated that increasing the nutrient density of diets through the addition of fat, together with careful regulation of nutrient intake, resulted in improved growth performance and carcass composition.

Studies on some chemical aspects of kusum oil

AbstractChemical methods, chromatography and infrared spectroscopy have been applied to ascertain the location and nature of the cyanogenic compounds in kusum oil. Observations indicate the cyanogenic compounds to be a part of glyceride molecules in which one of the hydroxyl groups of the latter is bonded to the cyanogenic compound through an ether linkage. Chromatographic behavior of the isolated cyanogenic compounds further indicates that at least two glyceride molecules are involved. These glycerides are predominantly esterified with saturated fatty acids.