Diglyceride Content Research Articles

Effects of pre‐deacidification on 3‐MCPDE and GE contents of high‐acid oils during refining

SummaryCrude fats and oils may have high free fatty acid (FFA) content depending on raw material quality and processing conditions. Their refining is always a challenge due to refining loss and the formation of some process contaminants such as 3‐monochloropropane‐1,2‐diol esters (3‐MCPDE), and glycidyl esters (GE). In this study, crude hazelnut oil having 12.10% FFA was degummed, bleached, and pre‐deacidified by a molecular distillation (MD) unit before neutralisation and deodorisation. Changes in FFA, diglyceride(DG), 3‐MCPDE, GE, and tocopherol contents were monitored. Almost no changes were detected in FFA and DG contents during degumming and bleaching while the latter resulted in the 3‐MCPDE formation and GE reduction. Some tocopherol losses were also observed after these steps. On the other hand, a huge amount of FFA was distilled (from 12.10% to 1.71%) by the MD process performed at 200 °C, 0.25 mbar, as well as with a 53.6% loss of tocopherol. The samples were then subjected to deodorisation before (MD‐PHY) and after neutralisation (MD‐CHE) at 230 °C under 2 mbar absolute pressure for 2, 4, and 8 h. While some 3‐MCPDE and GE formations were detected during MD‐CHE, there were almost no formations in these contaminants after MD‐PHY. When the bleached oil having 12.10% FFA was also directly deodorised at given conditions, no formations but some reductions in 3‐MCPDE and GE contents of the oils were determined, possibly because of esterification of FFA with DGs that are an important precursor of these contaminants.

Pickering emulsion stabilized by quercetin-β-cyclodextrin-diglyceride particles: Effect of diglyceride content on interfacial behavior and emulsifying property of complex particles

This research develops diacylglycerol (DAG) based Pickering emulsions with enhanced oxidative stability stabilized by self-assembled quercetin/DAG/β-cyclodextrin (β-CD) complexes (QDCCs) using a one-step agitation method. Influence of DAG content (5%, 15%, 40%, and 80%, w/w) on the self-assembly behavior, interfacial properties, and emulsifying ability of complex particles was investigated. SEM, XRD and ATR-FTIR studies confirmed the formation of ternary composite particles. QDCCs in 80% DAG oil had the highest quercetin encapsulation efficiency (6.09 ± 0.01%), highest DPPH radical scavenging rate and ferric reducing antioxidant property (FRAP). β-CD and quercetin adsorption rates in emulsion with 80% DAG oil were 88.4 ± 2.53% and 98.34 ± 0.15%, respectively. Pickering emulsions with 80% DAG had the smallest droplet size (8.90 ± 1.87 μm) and excellent oxidation stability. This research develops a novel approach to regulate the physicochemical stability of DAG-based emulsions by anchoring natural antioxidants at the oil-water interface through a one-pot self-assembly method.

On-Line Monitoring of Enzymatic Degumming of Soybean Oil Using Near-Infrared Spectroscopy.

Degumming is an oil refinement process in which the naturally occurring phospholipids in crude vegetable oils are removed. Enzymatic degumming results in higher oil yield and more cost-efficient processing compared to traditional degumming processes using only water or acid. Phospholipase C hydrolyses phospholipids into diglycerides and phosphate groups during degumming. The diglyceride content can therefore be considered a good indicator of the state of the enzymatic reaction. This study investigates the use of near-infrared (NIR) spectroscopy and chemometrics to monitor the degumming process by quantifying diglycerides in soybean oil in both off-line and on-line settings. Fifteen enzymatic degumming lab scale batches originating from a definitive screening design (with varying water, acid, and enzyme dosages) were investigated with the aim to develop a NIR spectroscopy prediction method. By applying tailored preprocessing and variable selection methods, the diglyceride content can be predicted with a root mean square error of prediction of 0.06% (w/w) for the off-line set-up and 0.07% (w/w) for the on-line set-up. The results show that the diglyceride content is a good indicator of the enzyme performance and that NIR spectroscopy is a suitable analytical technique for robust real-time diglyceride quantification.

The lipidomic and inflammatory profiles of visceral and subcutaneous adipose tissues are distinctly regulated by the SGLT2 inhibitor empagliflozin in Zucker diabetic fatty rats

The pharmacological inhibition of sodium-glucose cotransporter 2 (SGLT2) has emerged as a treatment for patients with type 2 diabetes mellitus (T2DM), cardiovascular disease and/or other metabolic disturbances, although some of the mechanisms implicated in their beneficial effects are unknown. The SGLT2 inhibitor (SGLT2i) empagliflozin has been suggested as a regulator of adiposity, energy metabolism, and systemic inflammation in adipose tissue. The aim of our study was to evaluate the impact of a 6-week-empagliflozin treatment on the lipidome of visceral (VAT) and subcutaneous adipose tissue (SAT) from diabetic obese Zucker Diabetic Fatty (ZDF) rats using an untargeted metabolomics approach. We found that empagliflozin increases the content of diglycerides and oxidized fatty acids (FA) in VAT, while in SAT, it decreases the levels of several lysophospholipids and increases 2 phosphatidylcholines. Empagliflozin also reduces the expression of the cytokines interleukin-1 beta (IL-1β), IL-6, tumor necrosis factor-alpha (TNFα), monocyte-chemotactic protein-1 (MCP-1) and IL-10, and of Cd86 and Cd163 M1 and M2 macrophage markers in VAT, with no changes in SAT, except for a decrease in IL-1β. Empagliflozin treatment also shows an effect on lipolysis increasing the expression of hormone-sensitive lipase (HSL) in SAT and VAT and of adipose triglyceride lipase (ATGL) in VAT, together with a decrease in the adipose content of the FA transporter cluster of differentiation 36 (CD36). In conclusion, our data highlighted differences in the VAT and SAT lipidomes, inflammatory profiles and lipolytic function, which suggest a distinct metabolism of these two white adipose tissue depots after the empagliflozin treatment.

Feasibility of total polar compound and its five components to evaluate the deterioration of heated and fried oil: Aspect of regulations of various countries

This work discussed the feasibility of total polar compounds (TPC) and its five components to evaluate the deterioration of heated and fried oil from correlation, characteristic composition, and regulation aspects. Results showed that the TPC, oxidized triglyceride oligomer and dimer (TGO + TGD), and monomer (oxTGM) could be individually used to evaluate the deterioration of heated oil (P < 0.01), while the quality control of fried oil required both TPC and oxTGM. The TPC index, currently regulated by most countries, has not achieved the supervision of oxTGM in fried oil (P > 0.05). But at discarding points of TPC 24%, 25%, and 25%, oxTGM content in fried oil was as low as 3.5–3.6 g/100g, while diglyceride (DG) content (hydrolysis products or possibly broken oxTGM) reached 9.0–11.0 g/100g. The effectiveness of relevant regulation settings in different countries was also re-evaluated. The health effect caused by oxTGM and DG may be a problem that raised worldwide concern.

UHPLC-Q-Exactive Orbitrap MS/MS-based untargeted lipidomics reveals molecular mechanisms and metabolic pathways of lipid changes during golden pomfret (Trachinotus ovatus) fermentation

Fermented golden pomfret (a popular marine fish product) is prepared via spontaneous fermentation. However, no comprehensive analysis has been reported on its lipid composition and metabolism. Herein, UHPLC-MS/MS-based untargeted lipidomic analysis identified 998 lipids (six classes; 29 subclasses) in fermented golden pomfret, including glycerolipids (47.70%) and glycerophospholipids (32.06%). As fermentation proceeded, triglyceride and diglyceride contents increased and subsequently decreased, while that of poly-unsaturated fatty acid-containing lipids increased (including those with docosahexaenoic acid, eicosapentaenoic acid, and docosapentaenoic acid). Pathway enrichment analysis identified seven lipid-related metabolic pathways, with the glycerophospholipid pathway found to be the most pertinent. Moreover, the decreased abundance of phosphatidylethanolamines and phosphatidylcholines during fermentation results from their high unsaturated fatty acid (FA) content. Indeed, essential FA contents increase following fermentation, due to their occurrence as glycerolipid side chains. Collectively, the results of this study provide a theoretical reference for optimizing the quality of fermented fish products.

Furan formation in some vegetable oils during heat treatments

Furan formations were monitored in commercially refined sunflower, soybean and olive oils during heat treatments at 170, 180 and 190 °C for 0, 2, 4, 6 and 8 h. The lowest furan concentrations were detected in sunflower oil at all temperatures, while soybean oil generated the highest furan concentration at 190 °C at the end of 8th hour. Furan contents were higher in olive oil at 170 and 180 °C, which might be due to its high diglyceride content. Furan formation linearly increased with time. Zero-order kinetic equations were used to determine kinetic parameters. Temperature was found effective on the furan formation because increases in reaction rate constants were observed by increasing the temperature. Using Arrhenius equation, activation energies of sunflower, soybean and olive oils were calculated as 45.08, 100.24 and 22.41 J/mol, respectively.

Quality detection of tea oil by 19F NMR and 1H NMR

The nuclear magnetic resonance (NMR) technique was applied to monitor the quality of tea oil herein. The adulteration of virgin tea oil was monitored by 19F NMR and 1H NMR. The 19F NMR technique was used as a new method to detect the changes in quality and hydroperoxide value of tea oil. The research demonstrates that 19F NMR and 1H NMR can quickly detect adulteration in tea oil. High temperature caused a decrease in the ratio D and increase in the total diglyceride content. Some new peaks belonging to the derivatives of hydroperoxides appeared at δ-108.21 and δ-109.05 ppm on the 19F NMR spectrum when the oil was autoxidized and became larger when the hydroperoxide value increased. These results have great significance in monitoring the moisture content, freshness and oxidation status of oils and in detecting adulteration in high priced edible oils by mixing with cheap oils.

Cocoa olein glycerolysis with lipase &lt;em&gt;Candida antarctica&lt;/em&gt; in a solvent free system

In this paper we present the valorization of cocoa olein obtained from the acid fat-splitting of soapstocks. The aim is to develop a solvent free process (enzymatically catalyzed) to maximize the production of a final product with high content of monoglycerides (MAG) and diglycerides (DAG). The effect of the enzyme dose, glycerol content, reaction times as well as the modification of the raw material and pressure were studied. The yield of the reaction increased up to 90-95% when using a vacuum of 2-3 mbar at 65 °C, enough to evaporate the water which is generated as a by-product, an enzyme dose of 1% and molar ratio oil:glycerol of 1:2. The highest yield in terms of MAG and DAG production was obtained by starting from a raw material which was rich in free acidity (FFA), rendering oil with 33.4 and 44.2% MAG and DAG, respectively. Short reaction times (6-8 h) were observed compared to previously reported results (24 h).

The Serine Carboxypeptidase-Like Gene SCPL41 Negatively Regulates Membrane Lipid Metabolism in Arabidopsis thaliana.

The Arabidopsis has 51 proteins annotated as serine carboxypeptidase-like (SCPL) enzymes. Although biochemical and cellular characterization indicates SCPLs involved in protein turnover or processing, little is known about their roles in plant metabolism. In this study, we identified an Arabidopsis mutant, bis4 (1-butanol insensitive 4), that was insensitive to the inhibitory effect of 1-butanol on seed germination. We cloned the gene that was defective in bis4 and found that it encoded an SCPL41 protein. Transgenic Arabidopsis plants constitutively expressing SCPL41 were generated, oil body staining and lipidomic assays indicated that SCPL41-overexpressing plants showed a decrease in membrane lipid content, especially digalactosyl diglyceride (DGDG) and monogalactosyl diglyceride (MGDG) contents, while the loss of SCPL41 increased the membrane lipid levels compared with those in wild-type plants. These findings suggested that SCPL41 had acquired novel functions in membrane lipid metabolism.

Effects of Long-Chain Fatty Acyl-CoA Synthetase 1 on Diglyceride Synthesis and Arachidonic Acid Metabolism in Sheep Adipocytes.

Long-chain fatty acyl-CoA synthetase (ACSLs) is an essential enzyme for the synthesis of fatty acyl-CoA. ACSL1 plays a key role in the synthesis of triglycerides, phospholipids, and cholesterol esters. Background: In the current study, triglyceride content did not increase after overexpression of the ACSL1 gene. Methods: RNA-seq and lipid metabolome profiling were performed to determine why triglyceride levels did not change with ACSL1 overexpression. Results: Fatty acyl-CoA produced by ACSL1 was determined to be involved in the diglyceride synthesis pathway, and diglyceride content significantly increased when ACSL1 was overexpressed. Moreover, the arachidonic acid (AA) content in sheep adipocytes significantly increased, and the level of cyclooxygenase 2 (COX2) expression, the downstream metabolic gene, was significantly downregulated. Knocking down the ACSL1 gene was associated with an increase in COX2 mRNA expression, as well as an increase in prostaglandin content, which is the downstream metabolite of AA. Conclusions: The overexpression of the ACSL1 gene promotes the production of AA via downregulation of COX2 gene expression.

Perilipin 5 Deletion in Hepatocytes Remodels Lipid Metabolism and Causes Hepatic Insulin Resistance in Mice.

Defects in hepatic lipid metabolism cause nonalcoholic fatty liver disease and insulin resistance, and these pathologies are closely linked. Regulation of lipid droplet metabolism is central to the control of intracellular fatty acid fluxes, and perilipin 5 (PLIN5) is important in this process. We examined the role of PLIN5 on hepatic lipid metabolism and systemic glycemic control using liver-specific Plin5-deficient mice (Plin5LKO ). Hepatocytes isolated from Plin5LKO mice exhibited marked changes in lipid metabolism characterized by decreased fatty acid uptake and storage, decreased fatty acid oxidation that was associated with reduced contact between lipid droplets and mitochondria, and reduced triglyceride secretion. With consumption of a high-fat diet, Plin5LKO mice accumulated intrahepatic triglyceride, without significant changes in inflammation, ceramide or diglyceride contents, endoplasmic reticulum stress, or autophagy. Instead, livers of Plin5LKO mice exhibited activation of c-Jun N-terminal kinase, impaired insulin signal transduction, and insulin resistance, which impaired systemic insulin action and glycemic control. Re-expression of Plin5 in the livers of Plin5LKO mice reversed these effects. Together, we show that Plin5 is an important modulator of intrahepatic lipid metabolism and suggest that the increased Plin5 expression that occurs with overnutrition may play an important role in preventing hepatic insulin resistance.

Cellular toxicity of dietary trans fatty acids and its correlation with ceramide and diglyceride accumulation

High fatty acid (FA) levels are deleterious to pancreatic β-cells, largely due to the accumulation of biosynthetic lipid intermediates, such as ceramides and diglycerides, which induce ER stress and apoptosis. Toxicity of palmitate (16:0) and oleate (18:1 cis-Δ9) has been widely investigated, while very little data is available on the cell damages caused by elaidate (18:1 trans-Δ9) and vaccenate (18:1 trans-Δ11), although the potential health effects of these dietary trans fatty acids (TFAs) received great publicity. We compared the effects of these four FAs on cell viability, apoptosis, ER stress, JNK phosphorylation and autophagy as well as on ceramide and diglyceride contents in RINm5F insulinoma cells. Similarly to oleate and unlike palmitate, TFAs reduced cell viability only at higher concentration, and they had mild effects on ER stress, apoptosis and autophagy. Palmitate increased ceramide and diglyceride levels far more than any of the unsaturated fatty acids; however, incorporation of TFAs in ceramides and diglycerides was strikingly more pronounced than that of oleate. This indicates a correlation between the accumulation of lipid intermediates and the severity of cell damage. Our findings reveal important metabolic characteristics of TFAs that might underlie a long term toxicity and hence deserve further investigation.

Blood Plasma Phospholipids and Cholesterol during Hibernation of the Long-Tailed Ground Squirrel

Seasonal changes in the levels of phospholipids, diglycerides, cholesterol, and total protein in the blood plasma were investigated during hibernation of the long-tailed ground squirrel Spermophilus undulatus. During the winter period, the levels of phosphatidylcholine, phosphatidylinositol, phosphatidylethanolamine, lysophosphatidylcholine, and sphingomyelin phospholipids (per 1 mg of plasma protein) were increased in both torpid and active ground squirrels by 70–80, 50, 600–700, 70, and 150–200%, respectively; the level of phosphatidylserine did not change in comparison to the summer period. The plasma phospholipid composition differed between hibernating and active summer animals: in winter, the phosphatidylcholine mol % decreased by 20%, phosphatidylinositol and phosphatidylethanolamine increased by 3–4 times, and the phosphatidylserine mol % decreased by 50%, while sphingomyelin and lysophosphatidylcholine did not change in comparison to summer animals. In hibernating ground squirrels, the plasma cholesterol levels increased by two times, the diglyceride content diminished by 60%, and the level of protein (in milligrams per 1 mL plasma) increased by 20%. The simultaneous increase in the levels of cholesterol and total phospholipids, as well as the pronounced specific changes in the levels of individual phospholipids in the blood plasma of hibernating ground squirrels, indicate the involvement of plasma lipoprotein lipids in the molecular mechanisms of adaptation to natural hypobiosis in mammals and a possible role of these mechanisms in systemic reactions to damaging factors.

Fatty acids and cholesterol in the liver cell nuclei of hibernating Yakutian ground squirrels.

The content of neutral lipids in tissue homogenates and liver cell nuclei of hibernating Yakutian ground squirrels was studied. In homogenates, hibernation increases the content of fatty acids and reduces the content of glycerides and cholesterol. When studying the liver cell nuclei of torpid winter ground squirrels, we detected a twofold increase in the content of fatty acids, cholesterol, and monoglycerides as compared to the "summer" ground squirrels. In the active "winter" ground squirrels, as compared to the torpid winter ones, the content of cholesterol did not change, whereas the content of fatty acids, monoglycerides, and diglycerides decreased but remained higher than in the "summer" ground squirrels.

Quantitative and qualitative analysis of bioactive components present in virgin coconut oil

AbstractThe hot and cold extracted virgin coconut oil (VCO) has been subjected to the various quality parameters. There was a no significant difference in iodine value, saponification value, refractive index, fatty acid profile, specific gravity, and moisture content of hot extracted virgin coconut oil (HEVCO), cold extracted virgin coconut oil (CEVCO), and copra oil (CCO) samples. The phenolic components of the HEVCO, CEVCO, and CCO were found to be 650.35 ± 25.11 μg/g, 401.23 ± 20.11 μg/g, and 182.82 ± 15.24 μg/g, respectively. The antioxidant activity ranged from 80 to 87% in HEVCO, 65 to 70% in CEVCO, and 35 to 45% in CCO. The results showed that VCO obtained from hot extraction process contained more total polyphenol, antioxidant activity, tocopherol, phytosterol, monoglycerides, and diglyceride content in comparison to CEVCO and CCO samples.

Lipase-catalyzed glycerolysis of olive oil in organic solvent medium: Optimization using response surface methodology

Enzymatic glycerolysis of olive oil for mono- (MG) and diglycerides (DG) synthesis was investigated. Several pure organic solvents and co-solvent mixtures were screened in a batch reaction system. The yields of MG and DG in co-solvent mixtures exceeded those of the corresponding pure organic solvents. Batch reaction conditions of the glycerolysis reaction, the lipase amount, the glycerol to oil molar ratio, the reaction time, and temperature, were studied. In these systems, the high content of reaction products, especially MG (55.8 wt%) and DG (16.4wt%) was achieved at 40 °C temperature and 0.025 g of lipase with relatively low glycerol to oil molar ratio (2: 1) within 4 h of reaction time in isopropanol/tert-butanol (1: 3) solvent mixture. Glycerolysis reaction was optimized with the assistance of response surface methodology (RSM). Optimal condition for reaction conversion was recommended as lipase amount 0.025 g, glycerol to oil molar ratio 2: 1, reaction time 4 h and temperature 40 °C.

An insight on acyl migration in solvent-free ethanolysis of model triglycerides using Novozym 435

In this work, the ethanolysis of triglycerides catalyzed by immobilized lipase was studied, focusing on the secondary reaction of acyl migration. The catalytic tests were performed in a solvent-free reaction medium using Novozym 435 as biocatalyst.The selected experimental variables were biocatalyst loading (5–20mg), reaction time (30–90min), and chain length of the fatty acids in triglycerides with and without unsaturation (short (triacetin), medium (tricaprylin) and long (tripalmitin/triolein)).The formation of 2-monoglyceride by ethanolysis of triglycerides was favored by long reaction times and large biocatalyst loading with saturated short- to medium-chain triglycerides. In the case of long-chain triglycerides, the formation of this monoglyceride was widely limited by acyl migration.In turn, acyl migration increased the yield of ethyl esters and minimized the content of monoglycerides and diglycerides. Thus, the enzymatic synthesis of biodiesel was favored by long-chain triglycerides (which favor the acyl migration), long reaction times and large biocatalyst loading.The conversion of acylglycerides made from long-chain fatty acids with unsaturation was relatively low due to limitations in their access to the active site of the lipase.

&lt;sup&gt;19&lt;/sup&gt;F NMR method for the determination of quality of virgin olive oil

This paper reported a potential analytical technique based on NMR spectroscopy for the determination of quality of olive oil. The model compounds with active hydrogen, including free sterols, free aliphatic alcohols, phenolics, and free fatty acids were determined by 19 F NMR upon derivation with 4-fluorobenzoyl chloride. Integration of the appropriate signals of the derivatives of the compounds in the corresponding 19 F NMR spectrum allows for the quantification of these compounds. 37 Samples of commercial olive oil and 5 samples of other plant oils were determined by 19 F NMR. The amount of diglycerides and the ratio of 1,2-diglycerides to the total amount of diglycerides were analyzed to monitor whether extra virgin olive oil was adulterated with low price olive oil and other plant oils or not. The results showed that the total diglyceride content should not be higher than 2.5% and the ratio (D) of 1,2-diglycerides to total diglycerides should be higher than 0.35 for extra virgin olive oil. This method is an easier, simpler, safer, faster and more reliable technique for the determination of the quality of olive oil and can also be extended to monitoring the quality of ordinary edible oils.

Integrin α1-null Mice Exhibit Improved Fatty Liver When Fed a High Fat Diet Despite Severe Hepatic Insulin Resistance

Hepatic insulin resistance is associated with increased collagen. Integrin α1β1 is a collagen-binding receptor expressed on hepatocytes. Here, we show that expression of the α1 subunit is increased in hepatocytes isolated from high fat (HF)-fed mice. To determine whether the integrin α1 subunit protects against impairments in hepatic glucose metabolism, we analyzed glucose tolerance and insulin sensitivity in HF-fed integrin α1-null (itga1(-/-)) and wild-type (itga1(+/+)) littermates. Using the insulin clamp, we found that insulin-stimulated hepatic glucose production was suppressed by ∼50% in HF-fed itga1(+/+) mice. In contrast, it was not suppressed in HF-fed itga1(-/-) mice, indicating severe hepatic insulin resistance. This was associated with decreased hepatic insulin signaling in HF-fed itga1(-/-) mice. Interestingly, hepatic triglyceride and diglyceride contents were normalized to chow-fed levels in HF-fed itga1(-/-) mice. This indicates that hepatic steatosis is dissociated from insulin resistance in HF-fed itga1(-/-) mice. The decrease in hepatic lipid accumulation in HF-fed itga1(-/-) mice was associated with altered free fatty acid metabolism. These studies establish a role for integrin signaling in facilitating hepatic insulin action while promoting lipid accumulation in mice challenged with a HF diet.