The composition of orange roughy (Hoplostethus atlanticus) roe lipids

Lipid analysis was carried out on orange roughy (Hoplostethus atlanticus) roe oil. Various chromatographic analytical techniques were compared and it was shown, although total orange roughy oil was rich in wax esters, that roe oil contained triacylglycerol and phospholipids as the principal components. The fatty acid content of the individual lipids (except wax esters) had 16:0, 18:1, 20:1, 20:5 and 22:6 as their major constituents.     

Clinical application of C18 and C20 chain length polyunsaturated fatty acids and their biotechnological production in plants

A potential revolution in FA therapies is on the horizon. In recent years, the full magnitude of various FA treatments and their overall importance to health has become increasingly apparent. Fetal and infant nutrition studies have clearly shown that FA status at birth can have life-long health implications affecting eye and brain function, insulin resistance, and blood pressure control. As well, nutrition studies have identified dietary imbalances and deficiencies that have the potential to alter the health of future generations severely and to promote progression of age-related degenerative disorders. Mixtures of naturally occurring FA have shown promise as therapeutic agents for a diverse range of health conditions including atopic eczema, rheumatoid arthritis, cardiovascular disease, and neurological problems. Through the 1990s, the creation of technologies to concentrate and formulate pharmacologically active individual FA components as well as tailored combinations propelled development of this new drug category. However, high production costs and government regulatory encumbrance limited the expansion of this emerging pharmaceutical sector. Fortunately, many countries are now creating regulatory frameworks that are better suited for product evaluation and control of the manufacturing FA products than historical drug models, and hence expansion in this area is now anticipated.     

Triglyceride deposition in tissues of germinating coconut (Cocos nucifera linn)

Coconut is the largest oilseed. In the present investigation, various lipid classes, such as triacylglycerol, free fatty acid, diacylglycerol, and their fatty acid compositions were determined from three regions of germinating coconut at three stages of germination. In this process, triacylglycerol was hydrolyzed and resynthesized in the haustorium tissue. Cooperative participation of various tissues, such as endosperm, haustorium, and embryo, was therefore involved in the process of germination of coconut.     

Autoxidation of synthetic isomers of triacylglycerol containing eicosapentaenoic acid

Several triacylglycerols (TAG) that contained eicosapentaenoic acid (EPA) were chemically synthesized and stored at 25°C to assess the influence of TAG structure on oxidative stability and formation of oxidation products. Oxidative stability was evaluated by oxygen consumption during storage of the TAG. Autoxidation products of TAG were analyzed by high-performance liquid chromatography (HPLC) and liquid chromatography-mass spectrometry (LC-MS). Results showed that a 2:1 (mole/mole) mixture of trieicosapentaenoylglycerol (EEE) and tripalmitoylglycerol (PPP) was most susceptible to autoxidation. The oxidative stability of TAG that contained EPA and palmitic acid was negatively correlated with the moles of EPA in a single TAG molecule. When TAG with one EPA and two other fatty acids were oxidized, chainlength of constituent fatty acids hardly affected the oxidative stability of EPA-containing TAG molecules, except for stearic acid. HPLC and LC-MS analyses showed that monohydroperoxides were major oxidation products regardless of type of TAG. Bis- and tris-hydroperoxides were formed during autoxidation of EEE and dieicos-apentaenoylpalmitoylglycerol. Monohydroperoxy epidioxides were found in all autoxidized TAG. These observations suggested that TAG structure affected the oxidation of TAG with highly unsaturated fatty acids.     

The positional and fatty acid selectivity of oat seed lipase in aqueous emulsions

The positional and fatty acid selectivities of oat (Avena sativa L.) seed lipase (triacylglycerol hydrolase EC 3.1.1.3) were examined. Pure triacylglycerols were used as substrates. The products of lipolysis were examined by thin-layer chromatography and gas-liquid chromatography. Only symmetrical triacylglycerols were used as substrates; thus potential complications arising from stereobias were avoided. Controls were carried out with a lipase specific for primary positions. The lipase from oat seeds catalyzed the hydrolysis of both primary and secondary esters. When the lipase was tested upon mixtures of homoacid triacylglycerols (triacylglycerols composed of the same three fatty acids), the lipase acted most rapidly upon those containing oleate, elaidate, linoleate and linolenate. Strong intermolecular selectivity against homoacid triacylglycerols containing palmitate, petroselinate and stearate was observed. Comparison of assays performed at 26°C with those performed at 45°C showed that selectivity was temperature-independent. When mixed-acid triacylglycerols containing both oleate and stearate were treated with lipase, intramolecular selectivity was observed, with oleate hydrolysis predominating. From this work and earlier work, it can be concluded that the selectivity exhibited by the oat seed lipase is similar to that of the lipase fromGeotrichum candidum, except that the oat seed lipase attacks elaidate, a fatty acyl group with atrans double bond, whereas theG. candidum lipase strongly discriminates against elaidate.     

Determination of triacylglycerols in food by high-performance liquid chromatography

Food contamination is a major global issue and the challenges are increasing. Alternative methodology using lipids in detecting contaminants and determining food ingredients is needed to supplement or replace current methodology. The core–shell column is considered to be a breakthrough for high-performance liquid chromatography. In this study, lipid profiling was performed using a C18 core–shell column to separate and identify triacylglycerols in oil and food. The chromatographic profiles were compared at various flow rates to determine their efficiency. The evaluation was done based on chromatographic resolution, resolving power, and separation efficiency. In addition, the height equivalent to a theoretical plate of the column was determined and a comparison was made at the same linear velocity along with the peak capacity. The most efficient flow rate was 400?µL/min, and by applying the methodology, triacylglycerols from edible oil and food were extensively profiled. The results show that triacylglycerol profiles may be utilized as a biomarker for food quality. This alternative methodology provided a comprehensive profile of triacylglycerols in oil and food that allowed the identification of unique triacylglycerol biomarkers for practical analysis.     

Effect of chemical interesterification on triacylglycerol and solid fat contents of palm stearin,sunflower oil and palm kernel olein blends

Palm stearin (POs) with an iodine value of 41.4, sunflower oil (SFO) and palm kernel olein (PKOo) were blended in various ratios according to a three‐component mixture design and subjected to chemical interesterification (CIE). Triacylglycerol (TAG) and solid fat content (SFC) profiles of the chemically interesterified (CIEed) blends were analyzed and compared with those of the corresponding non‐CIEed blends. Upon CIE, extensive rearrangement of fatty acids (FA) among TAG was evident. The concentrations of several TAG were increased, some decreased and several new TAG might also have been formed. The changes in the TAG profiles were reflected in the SFC profiles of the blends. The SFC of the CIEed blends, except the binary blends of POs/PKOo which experienced an increase in SFC following CIE, revealed that they were softer than their respective starting blends. Randomization of FA distribution within and among TAG molecules of POs and PKOo led to a modification in TAG composition of the POs/PKOo blends and improved miscibility between the two fats, and consequently diminished the eutectic interaction that occurred between POs and PKOo.     

α-Melt-mediated crystallization of 1-palmitoyl-2-oleoyl-3-stearoyl-sn-glycerol

The α-melt-mediated crystallization of 1-palmitoyl-2-oleoyl-3-stearoyl-sn-glycerol (POS) has been investigated by differential scanning calorimetry (DSC), combined with polarized-light microscopy. Starting from a completely liquid state, the melt was first cooled down and maintained at a temperature, T ₁, during a time, t ₁, where the α-phase formed. Then it was heated to a temperature, T ₂, above the melting point of α for isothermal solidification into a solid phase, which was identified as δ. Based upon DSC solidification peaks, the time-temperature-transformation (TTT) diagram of POS was constructed for these solidification conditions and was compared with the TTT diagram of direct crystallization from the melt. The α-melt-mediated solidification showed accelerated kinetics of the δ-phase. The effects of T ₁ and t ₁ were also studied: at short t ₁, crystallization was faster with a decreasing value of T ₁, whereas the opposite trend was observed for a longer plateau at T ₁. These tendencies were interpreted in terms of three competing phenomena: the density of δ-nuclei that can form during the plateau at T ₁, α-δ solid-state transformation, and memory effects of molecule arrangements in the α-remelted phase.     

The enzymatic hydrolysis of triglyceride-phospholipid mixtures in an organic solvent

The abilities of four commercially available lipolytic enzymes [three immobilized lipases—Lipozyme IM-20, SP-435 (Novo Biolabs, Danbury, CT), and AY-30/Celite (Amano Enzyme Co., Ltd., Troy, VA)—and a nonimmobilized Amano phospholipase B preparation] to hydrolyze mixtures of triacylglycerols (TG) and phospholipids (PL) were determined. All of the lipases hydrolyzed both types of substrates in water, with maximum rates of TG hydrolysis exceeding those of PL hydrolysis by between 20- and 200-fold. The phospholipase B preparation was inactive against both TG and PL in water. All the enzymes showed some activity against lipids in hexane. The amount of activity was sharply dependent on the amount of water added to the reaction. Lipozyme IM-20 and AY-30/Celite hydrolyzed both TG and PL in hexane. Their estimated initial activities were between 10- and 100-fold lower than those in water. Complete hydrolysis of the TG (measured as the hydrolysis of at least one ester bond in each molecule) was achieved, whereas only 40–60% of the phosphatidylcholine (PC) and phosphatidylethanolamine (PE) were hydrolyzed. Lipase SP-435 was inactive against TG in hexane but hydrolyzed PC at a rate comparable to that seen in water, and it achieved complete hydrolysis of this substrate. Amano phospholipase B was inactive against TG in hexane but completely hydrolyzed the PC. The abilities of the enzymes to hydrolyze the TG, PC, and PE components of soybean soapstock, a by-product of edible oil production, were also examined. Lipozyme IM-20 hydrolyzed all the TG and a fraction of the PL in soapstock. SP-435 and AY-30/Celite were active only on soapstock that had been acidified prior to being dissolved in hexane. SP-435 displayed significant activity only toward PE under these conditions, whereas AY-30/Celite was active only toward TG. Phospholipase B was inactive against soapstock in hexane. The identity of the acid used in the acidification of soapstock affected the degree of hydrolysis by AY-30/Celite, with nitric and hydrochloric acids giving the best activity.     

Impact of Lipoprotein Lipase Gene Polymorphism,S447X,on Postprandial Triacylglycerol and Glucose Response to Sequential Meal Ingestion

Lipoprotein lipase (LPL) is a key rate-limiting enzyme for the hydrolysis of triacylglycerol (TAG) in chylomicrons and very low-density lipoprotein. Given that postprandial assessment of lipoprotein metabolism may provide a more physiological perspective of disturbances in lipoprotein homeostasis compared to assessment in the fasting state, we have investigated the influence of two commonly studied LPL polymorphisms (rs320, HindIII; rs328, S447X) on postprandial lipaemia, in 261 participants using a standard sequential meal challenge. S447 homozygotes had lower fasting HDL-C (p = 0.015) and a trend for higher fasting TAG (p = 0.057) concentrations relative to the 447X allele carriers. In the postprandial state, there was an association of the S447X polymorphism with postprandial TAG and glucose, where S447 homozygotes had 12% higher TAG area under the curve (AUC) (p = 0.037), 8.4% higher glucose-AUC (p = 0.006) and 22% higher glucose-incremental area under the curve (IAUC) (p = 0.042). A significant gene–gender interaction was observed for fasting TAG (p = 0.004), TAG-AUC (P_interaction = 0.004) and TAG-IAUC (P_interaction = 0.016), where associations were only evident in men. In conclusion, our study provides novel findings of an effect of LPL S447X polymorphism on the postprandial glucose and gender-specific impact of the polymorphism on fasting and postprandial TAG concentrations in response to sequential meal challenge in healthy participants.