High Molecular Weight Triglycerides Research Articles

Production of omega 3-rich oils from underutilized chia seeds. Comparison between supercritical fluid and pressurized liquid extraction methods

Chia seeds constitute a promising source of α-linolenic acid (ALA). In the present work, an underutilized and cheaper set of chia seeds, which were discarded after the harvest according to quality criteria - named in this work as low oil content seeds (LOCS) - have been evaluated as a potential source for obtaining PUFA-enriched oils against the commonly studied high-quality chia seeds denoted as high oil content seeds (HOCS) in this study. Two efficient and environmental friendly techniques, supercritical fluid extraction (SFE) and pressurized liquid extraction (PLE), were evaluated to optimize the extraction process of chia oil. At 60 °C, by using pressurized food-grade ethanol, recoveries close to 100% were achieved from both sets of seeds in a short extraction time (10 min). By using SFE, the greatest oil extraction yield (>95%) was attained at the highest pressure and temperature conditions (45 MPa and 60 °C) after 240 min. At the early stage of SFE extraction, both LOCS and HOCS exhibited a similar kinetic behavior, reaching oil extraction rates of 0.59 g oil/min and 0.64 g oil/min, respectively. No differences were found between the fatty acid profile of the oils extracted from LOCS and HOCS both by PLE and SFE. ALA and linoleic acid (LA) concentrations ranged between 65‐68% and 17–23% respectively, and a predominance of high molecular weight triglycerides (≥ CN50), was found in all extracted oils. In conclusion, LOCS might constitute a new suitable raw material for the production of ALA-enriched oils. Concerning the extraction methods assayed, the oil was almost entirely recovered by both PLE and SFE at the used conditions.

Determination of pesticides in fatty matrices using gel permeation clean-up followed by GC-MS/MS and LC-MS/MS analysis: A comparison of low- and high-pressure gel permeation columns

Two low-pressure columns (Bio-Beads SX-3) and three high-pressure GPC columns were compared for clean-up of a wide range of pesticides in fatty matrices of vegetable or animal origin. The GPC fractions were analyzed by GC-MS/MS and LC-MS/MS without additional clean-up. The performance of the GPC clean-up on the five column types was compared in terms of solvent consumption, lipid removal, pesticide recovery and repeatability.It was found that for fatty matrices, mainly consisting of high molecular weight triglycerides i.e. most vegetable oils and animal fats, good fractionation is obtained for the majority of the pesticides. On the other hand, for fats and oils containing relatively high amounts of low molecular weight triglycerides, i.e. butter fat and palm kernel oil, none of the columns provided sufficient clean-up and cause interferences and system contamination, especially in the case of GC-MS/MS analysis. For the latter case, best results in terms of lipid removal and pesticide recovery were obtained on a set (2×300mmlength) of narrow bore (7.5mm ID) columns packed with 5µm PL Gel material. Column loadability is, however, much lower on that set of columns compared the other evaluated GPC columns, impairing overall method sensitivity.

Specialty Fats Enriched with Behenic and Medium Chain Fatty Acids from Palm Stearin by Lipase Acidolysis

AbstractStructured lipids containing behenic and medium chain (MC) fatty acids were prepared from palm stearin using 1,3‐specific lipase‐catalyzed acidolysis. Incorporation of MC and behenic acids was affected by proportion of substrate, type of fatty acids, reaction time, addition of water and quantity of lipase. It was found that incorporation of caproic acid was less compared to other longer chain fatty acids. Caprylic, capric and behenic acids shared similar incorporation (up to 32 %), which increased with the amount of fatty acids added and the time of reaction. The incorporation of these acids increased with addition of 1 % moisture and the increasing amount of enzyme from 5 to 10 % at the beginning of the reaction. Incorporating behenic and MC fatty acids, reduced palmitic and oleic acids considerably from palm stearin, the extent being the same as those incorporated. However, the reduction of linoleic acid was marginal. The solid fats content of the modified palm stearin containing MC and behenic acids were reduced at all temperatures due to a reduction in higher molecular weight triglycerides and an increasing proportion of lower chain triglycerides. The modified products of palm stearin with added capric and behenic acids were similar to commercial bakery shortenings and those with added capric acid were like salad or cooking oils or butter in melting characteristics.

Effect of molecular weight of triglycerides on the formation and rheological behavior of cubic and hexagonal phase based gel emulsions

The effect of triglyceride molecular weight on the formation and rheology of cubic (O/I 1) and hexagonal (O/H 1) phase based gel emulsions has been studied in water/C 12EO 8 systems. It was found that the addition of TDG (1,2,3-tridecanoyl glycerol) in the micellar solution leads to the formation of the I 1 phase, which can solubilize some added oil. From SAXS data, it is revealed that the interlayer spacing ( d) and the length of hydrophobic part ( r I) increase with increasing TDG concentration in the I 1 phase, whereas the effective cross-sectional area ( a s) decreases. After the oil solubilization limit, the d value remains nearly constant, indicating the I 1+O phase appears. The high viscosity of the I 1 phase facilitates the formation of the O/I 1 gel emulsion. It has been observed that the formation and stability of the O/I 1 and O/H 1 gel emulsion is highly dependent on the molecular weight of triglycerides, namely, the high molecular weight triglycerides show better performance (formation and stability) compared to the low molecular weight triglycerides. The rheological behavior of the I 1 phase was found to change from viscoelastic to elastic nature with TDG content. The values of the complex viscosity, ∣ η *∣ show different trends at different fixed frequencies within the I 1 phase, whereas it decrease monotonically in the O/I 1 gel emulsions. The increasing values of the ∣ η *∣ (at lower frequency) could be due to the neighboring micellar interaction and decreasing values of the ∣ η *∣ in the O/I 1 gel emulsion could relate to the volume fraction of the I 1 phase in the system. It is also figured out that the rheological parameters (elastic modulus, viscous modulus, and ∣ η *∣) of the O/I 1 the gel emulsion do not depend on the oil nature, whereas the O/H 1 gel emulsion shows oil nature dependency.

Modification of goat milk fat triglycerides by immobilized lipase

The lipid fraction of goat milk was subjected to transesterification using a commercially available immobilized lipase to decrease the amount of short- and medium-chain fatty acids (C 4 -C 14 ) by enrichment of the reaction mixture with long-chain (C 18:1 and C 18:2 ) fatty acids. Aliquots were taken during transesterification at different reaction times and analyzed for triglycerides and their fatty acid components. The gas chromatographic analyses of triglycerides (previously isolated by thin-layer chromatography) showed that at 6 h reaction under the experimental conditions led to the greatest reduction of the low molecular weight triglycerides (C 22 -C 38 ) and concomitantly to the greatest increase in the higher molecular weight triglycerides (C 48 -C 54 ). These changes correlated with the variations observed in the fatty acids of the triglyceride fraction.

Lipase-catalyzed hydrolysis of Crambe oil in AOT-isooctane reversed micelles

The hydrolysis by 1,3-specific lipases (Humicola lanuginosa, Mucor miehei, Rhizopus delemar andRhizopus javanicus) of the highly symmetric, high molecular weight triglycerides fromCrambe abyssinica (Crambe) seed oil is studied in an AOT-stabilized microemulsion system. Enzyme kinetic data shows that, of the lipases studied,Rhizopus javanicus lipases exerts the highest hydrolytic activity towards this new seed oil.

Relationship between triglyceride structure and softening point of milk fat

SummaryEight samples of milk fat were selected for softening point (SP) range. They were separated into high, medium and low molecular weight triglyceride fractions by silicic acid-column chromatography to enable further separation into triglyceride classes by silver ion adsorption thin-layer chromatography. Correlation between triglyceride class content and SP was low. The molecular species composition of the triglyceride classes was determined and correlated with SP. The best correlations were between SP and some low and some high molecular weight triglycerides of the total fat and the trisaturated (SSS) triglyceride class. Correlation coefficients were determined between SP and mole percentage of individual fatty acids and groups of acids. The highest correlations were between SP and individual short chain-length fatty acids (C4–C10) and groupings of short chain-length acids (C4–C10) and groupings of long chain-length acids (C16–C20). The triglyceride class composition of a sample of milk fat was determined before and after interesterification. Interesterification increased the SP from 31·6 to 36·3 °C and produced increased amounts of both low and high and decreased amounts of medium molecular weight triglyceride molecular species in all triglyceride classes. The increases in the amounts of high molecular weight triglycerides were several times greater than the increase in the amounts of low molecular weight triglycerides.

Relationship between trisaturated glyceride composition and the softening point of milk fat

SummaryNo relationship was found between the trisaturated glyceride content and the softening point (SP) of milk fat. Inter-esterification of milk fat increased its SP, but did not change the trisaturated glyceride content or the fatty acid composition of the trisaturated glyceride fraction. Inter-esterification increased the amount of both low and high and decreased the amount of medium molecular weight triglyceride species in the trisaturated glyceride fraction. The increase in the amount of high molecular weight triglyceride species was up to 3 times greater than the increase in the amount of low molecular weight triglycerides.The triglyceride species composition of the trisaturated glyceride fraction of milk fat was found to vary seasonally. Excellent correlation was found between SP and groups of low molecular weight triglycerides, groups of high molecular weight triglycerides and some individual triglyceride species. Correlation coefficients were higher than those previously reported between groups of fatty acids and SP.

Positional distribution of fatty acids in the triglycerides of bovine milk fat with elevated levels of linoleid acid.

AbstractA stereospecific distribution of fatty acids in bovine milk fat containing 15.5% linoleic acid has been compared with the distribution in bovine milk fat containing a normal level (1.8%) of linoleic acid. The positional distribution was obtained by the separate analysis of milk fat triglycerides of high, medium, and low molecular weight. The order of preference for linoleic acid in the high molecular weight triglycerides was position 3>position 2 >position 1. There was an accompanying altered distribution of myristic acid and palmitic acid in favor of position 1 at the expense of position 3. However, the proportions of myristic acid and palmitic acid in position 2, relative to positions 1 and 3 were identifical in the high molecular weight fractions of the two milk fats. The distribution of linoleic acid in the medium molecular weight triglycrides of linoleic‐rich milk fat was position 1=position 2>position 3. This resulted in a change in the distribution of 18 carbon monounsaturated fatty acids in favor of position 2 at the expense of position 1, but the distribution of myristic acid and palmitic acid was virtually unaltered. The distribution of linoleic acid in the low molecular weight triglycerides was position 2>position 1>position 3. The amounts of myristic acid and palmitic acid in position 2 and of palmitic acid in position 1 decreased in the low molecular weight triglycerides of the milk fat containing elevated levels of linoleic acid. Changes in the distribution of fatty acids which were observed in the separate analysis of the high, medium, and low molecular weight triglycerides were not apparent when comparing the distribution in the total milk fats. For example, the distribution of myristic acid and palmitic acid appeared to be unchanged, while the distribution of 18 carbon monounsaturated fatty acids was slightly altered in favor of positions 2 and 3. Moreover, linoleic acid showed an almost equal preference for the three positions of the glycerol moiety in milk fat containing elevated levels of this fatty acid with some concentration at position 2.

Stearic Acid Metabolism by Mammary Cells

Dispersed cells, from lactating bovine and rat mammary glands, and bovine mammary tissue slices avidly absorbed and metabolized substrate 1-14C-stearic acid. Absorbed stearic acid was extensively desaturated to oleic acid by ruminant cells. Freshly dispersed cells from the cow surpassed all other preparations in absorption and desaturation of stearic acid.The preponderance of radioactive substrate was esterifled into glycerides, mainly triglycerides (>70%); the remainder (15 to 20%) was incorporated into phospholipids and 1 to 2% into cholesterol esters. Measurable labeled triglycerides were secreted into the culture media from functional bovine and rat cells. In bovine and rat mammary cells, radioactive stearic and oleic acids were esterifled mostly into triglyceride molecules with C40 to C52 aggregate acyl carbons, i.e. high molecular weight triglycerides, resolved by gas chromatography.The preponderance of the radioactivity in the phospholipids was associated with phosphatidylcholine, though all classes including phosphatidic acid contained measurable radioactivity.Distribution of radioactivity between stearic and endogenous oleic acid in various lipid classes and on specific positions of glycerolipids was also examined. Relative concentration of oleic acid was greatest in phospholipids where it was on positions sn1 and sn2 of the glycerol moiety. In triglycerides labeled oleic acid was mostly on the primary positions of the glycerol moiety.These observations are discussed with respect to corresponding data from in vivo studies of milk lipid biosynthesis.

GAS–LIQUID CHROMATOGRAPHIC FRACTIONATION OF NATURAL TRIGLYCERIDE MIXTURES BY CARBON NUMBER

Synthetic and naturally occurring triglyceride mixtures have been successfully separated according to their carbon number by gas–liquid chromatography on stainless steel columns (18 in. × 1/8 in. diameter) packed with 60–80 mesh Chromosorb W coated with 2.25% (w/w) SE-30. Complete and apparently quantitative separations of the simple triglycerides from trioctanoin to tristearin were achieved within 40 minutes in the temperature range of 200 to 320 °C. Under the working conditions (temperature programming), the columns had a theoretical plate number of 3500 to 5000 when calculated for tristearin. Although losses of the higher molecular weight triglycerides were occasionally encountered because of incomplete volatilization, there was no evidence of a fragmentation of the triglyceride molecules at the moment of volatilization (325 °C).