Monoacylglycerol Research Articles

Enzymatic synthesis of ω-3 fatty acids-based structured phospholipids: A novel solvent-free preparation approach and its catalytic mechanism

ω-3 fatty acids-based phospholipids (ω-3-PLs) exhibit higher bioavailability within organisms and stability compared to polyunsaturated fatty acids in their neutral forms. In this study, ω-3 fatty acids enriched partial acylglycerols (ω-3-AGs) were produced from hydrolysis of algal oil firstly. The effects of hydrolysis processing parameters such as enzyme type, enzyme loading, oil-water ratio, reaction temperature, and time were evaluated. Subsequently, ω-3-PLs were prepared via interesterification of ω-3-AGs with PLs catalyzed by PLA1. When monoacylglycerols (MAGs) reached 60% in partial acylglycerols, the interesterification reaction showed a marked improvement, leading to the achievement of the optimal final ω-3-PLs content of 38.93%. Using molecular docking techniques to speculate on the catalytic mechanism, the results indicate that MAGs exhibit an affinity of up to −6.33 kcal/mol with PLA1, verifying their critical role in the interesterification process.

Modulating the behavior of ethyl cellulose-based oleogels: The impact food-grade amphiphilic small molecules on structural, mechanical, and rheological properties

This work evaluates the ability of various lipid-based amphiphilic small molecules (ASMs) to modulate the mechanical and rheological properties of oleogels principally structured by ethyl cellulose (EC). Six ASMs varying in the chemical structure of their polar headgroups were used to produce EC-ASM oleogels. Stearic acid (StAc), monoacylglycerol (MAG), sodium stearoyl lactylate (SSL), and citric acid esters of monoglycerides (CITREM) all provided a dramatic enhancement in gel strength, while lactic acid (LACTEM) and acetic acid (ACETEM) esters produced only a marginal increase. Those additives which crystallized above 20 °C displayed pronounced changes in their network organization and crystal morphology in the presence of EC. Differences in the solid/liquid phase change behavior were also observed in select samples using differential scanning calorimetry. Both the small and large amplitude oscillatory shear responses were dependent on the ASM which was dependent on the chemistry of the headgroup, crystal network organization, and ability to plasticize the polymer network. The extent of thixotropic recovery was largely dependent on the polarity of functional groups in the ASMs, but was also influenced by the formation of a secondary crystal network. In general, ASMs which formed larger, system-spanning crystal networks (MAG, StAc) produced more brittle gels, while the highly hydrophilic, charged headgroup of SSL promoted a homogeneous distribution of small crystals, resulting in a tougher material. In the absence of a crystal network, stronger polar species in the ASM headgroup produced higher gel strength and increased elasticity. Thus, both ASM chemical structure and crystallization properties strongly contribute to the functionality of the resulting combined oleogelator systems.

Influence of oil base and gelling agent on the performance of oil gels

Abstract Oil gels, as a novel delivery system, have broad prospects in carrying nutrients and active substances. It has been found that the properties of oil gels are closely related to the types of oil bases and gelling agents used. In this study, soybean oil, sesame oil, and coconut oil were used as oil bases, while ethyl cellulose (EC), monoglycerides (MG), herbal extracts (HE), and hydroxypropyl methylcellulose-xanthan gum (HPMC-XG) were used as gelling agents to prepare different oil gels. The performance of the oil gels was evaluated based on appearance, microstructure, viscosity, oil-holding capacity, and drug-loading capability.

Enhanced Glycerolysis of Fatty Acid Methyl Ester by Static Mixer Reactor.

This study investigates the synthesis of monoglycerides (MGs) and diglycerides (DGs) from glycerol (G) and fatty acid methyl ester (FAME) using a static mixer reactor (SMR), which combines a static mixer (SM) with a reactor tank. The SMR integrates Kenics static mixers (KSM) and low-pressure drop static mixers (LPDSM) with varying length-to-diameter ratios (L/D = 1.0 and 1.5). Keys glycerolysis parameters, including the G:FAME molar ratio of 2:1-3:1, 2-3 wt % potassium hydroxide (KOH), and reaction time of 30-90 min at 150 °C were systematically explored. The SMR design allows precise control over the reaction time without altering the feed flow rate or tube length and avoiding agitator leakage. The optimal operating conditions, determined through a face-centered central composite design, resulted in 71.35% MGs and 14.20% DGs at a 3:1 molar ratio of G to FAME, 3 wt % KOH, 60 min, and 150 °C using an LPDSM with an L/D of 1.5. In comparison, an LPDSM with an L/D of 1 achieved 79.28% MGs and 10.17% DGs under the same conditions. When applied to purified crude glycerol, these conditions yielded 61.09% MGs and 23.44% DGs. The study found that a lower L/D ratio improved the mixing efficiency but increased the pressure drop. The SMR demonstrated superior performance in glycerolysis compared with conventional stirred tank reactors and ultrasonic probe reactors, indicating its potential for enhanced industrial application.

Application of Box-Behnken design in monoglycerides production via glycerolysis of palm oil using homogenizer reactor

The glycerolysis of triglycerides (TG) to produce monoglycerides (MG) is an important pathway for glycerol valorization. However, mass transfer resistance has significantly hindered the process efficiency because the reaction is a two-phase liquid-liquid reaction. In this study, a homogenizer was used as a high shear mixing reactor (HSM) to address such issue of mass transfer resistance, and was compared to a conventional mechanically stirred reactor (MS). The effects of the rotational speed, catalyst amount, molar ratio of Gly-to-TG, reaction temperature and reaction time on MG yield were investigated using NaOH as a homogeneous catalyst. Three reaction variables were investigated by statistical analysis using the Box-Behnken (BBK) experimental design, including Gly-to-TG molar ratio (2:1–4:1), catalyst loading (0.1–0.3 wt% TG), and reaction time (15–45 min). The results indicated that the predicted maximum MG yield of 63.4 % was achieved at a reaction time of 29 min, a Gly-to-TG molar ratio of 2.7:1, and a catalyst loading of 0.274 wt% of TG, which agreed with the experimental results. The yield efficiency of HSM was 1.27×10−4 g/J, which was 9.14-fold higher than that of MS at 1.39×10−5 g/J.

Natural deep eutectic solvents as green and homogeneous catalysts for the glycerolysis of stearic acid: Catalytic activity and kinetic studies

Emulsifier as the mixture of monoglycerides (MG) and diglycerides (DG) is widely used in the food industry such as bakery products, margarines, dairy products, and confectionary. This emulsifier can be produced by glycerolysis of fatty acids using acid catalyst. In this work, natural deep eutectic solvent (NADES) was chosen as a catalyst in the glycerolysis of stearic acid due to greener and sustainable catalyst with advantages such as low vapor pressure, non-toxic, biodegradable, and easy to reuse. The catalytic activity of the NADES, kinetic constants and activation energies for the reaction were investigated. The reaction was carried out at agitation speed (300 rpm), catalyst concentration (5 wt%), reaction temperatures (120 °C, 150 °C and 180 °C) and reactant mole ratios (1:2, 1:4 and 1:6). Choline chloride-sorbitol NADES has highest catalytic activity on the glycerolysis of stearic acid. The kinetic calculation results using choline chloride-sorbitol NADES as a catalyst validated that the reaction was pseudo second order with an activation energy of 64.04 kJ∙mol−1, and a collision factor of 196,696 L∙mol−1∙min−1. This kinetics data will be useful for reactor design in industrial applications.

Two monoacyl glycerols isolated from B. mycoides, B. weihenstephanensis and B. toyonensis and their antifungal activity against Lasiodiplodia theobromae, pathogen of cacao

In this work two known monoacyl glycerols, glycerol 1-monopalmitate and glycerol 1-monostearate, were isolated for the first time from B. mycoides, B. weihenstephanensis and B. toyonensis. These monoacyl glycerol compounds showed good antifungal activity specially, against Lasiodiplodia theobromae, which is the fungus affecting cacao. A study of the cell damage done by these monoacyl glycerols was performed in three phytopathogens, resulting in severe damage of reproductive structures, indicating for the first time the potent antifungal activity of these compounds. It could be a promising result to apply in agriculture crops. This work contributes with the research about Bacillus species secreting metabolites, since this is the first time that is reported about the mono acyl glycerols as compounds secreted by Bacillus species. Furthermore, this work explores the role that Bacillus genus can play in controlling important fungi in agriculturally important crops such as cacao.

Insights into the difference between diglyceride-oil based and triglyceride-oil based oleogels: Physical property, crystal structure and stability

This paper investigated the differences in the structure and properties of diglyceride (DAG) oleogels (DAG as the oil phase) and triglyceride (TAG) oleogels (TAG as the oil phase) with different gelator concentrations of beeswax (BW) and monoacylglycerol (MAG). When BW was used as gelator, compared with TAG oleogels, the mass of β′ crystals in DAG-oil based oleogels increased, the crystal network stability improved, and the G′ increased. In addition, the DAG-oil based oleogels prepared with BW showed hydrogen bonds. When MAG was used as gelator, the G′, the thermal and crystal network stability of DAG-oil based oleogels decreased compared to TAG oleogels, and large number of crystal clusters were formed. In addition, DAG-oil based oleogels showed lower oxidative stability than TAG oleogels. These results contribute to a better understanding the properties of DAG oil based oleogels and facilitate the development of low-fat functional plastic products.

Genome-wide identification and mining elite allele variation of the Monoacylglycerol lipase (MAGL) gene family in upland cotton (Gossypium hirsutum L.)

BackgroundMonoacylglycerol lipase (MAGL) genes belong to the alpha/beta hydrolase superfamily, catalyze the terminal step of triglyceride (TAG) hydrolysis, converting monoacylglycerol (MAG) into free fatty acids and glycerol.ResultsIn this study, 30 MAGL genes in upland cotton have been identified, which have been classified into eight subgroups. The duplication of GhMAGL genes in upland cotton was predominantly influenced by segmental duplication events, as revealed through synteny analysis. Furthermore, all GhMAGL genes were found to contain light-responsive elements. Through comprehensive association and haplotype analyses using resequencing data from 355 cotton accessions, GhMAGL3 and GhMAGL6 were detected as key genes related to lipid hydrolysis processes, suggesting a negative regulatory effect.ConclusionsIn summary, MAGL has never been studied in upland cotton previously. This study provides the genetic mechanism foundation for the discover of new genes involved in lipid metabolism to improve cottonseed oil content, which will provide a strategic avenue for marker-assisted breeding aimed at incorporating desirable traits into cultivated cotton varieties.

Effect of ultrasonication on microstructure, crystallization and rheological properties of mixed Monoglycerides and Tween 20 oleogel networks

The aim of this study was to investigate the impact of ultrasonication on the formation of crystalline network of monoglycerides (MGs) and Tween 20 (Tw20) in a continuous matrix of olive oil. Several analytical methods such as differential scanning calorimetry (DSC), confocal and polarized optical microscopy, rheometry, and infrared spectroscopy (FT-IR) were employed to characterize the ultrasonicated oleogel structures. DSC and FT-IR provided evidence that ultrasonication accelerated the crystallization of the β-polymorph of the monoglycerides. Confocal and optical microscopy revealed that ultrasonication resulted in shorter and thinner β-MGs crystals. The addition of Tw20 to the system led to formation of oil-in-oil emulsion gels with the β-MGs crystals acting as Pickering particles. Rheology showed that ultrasonication induced the formation of stronger but with lower yield stress oleogels. Overall, ultrasonication can modulate the structure of MGs-based crystallized networks, thereby influencing the thermomechanical properties, which could be beneficial for fat substitution in food products.

Expression and characterization of a thermostable monoacylglycerol lipase from thermophilic Geobacillus kaustophilus

Thermophilic Geobacillus kaustophilus HTA426 genome possesses a monoacylglycerol lipase (MAGL) gene. MAGLs can synthesize emulsifiers for use in the food and pharmaceutical industries from fatty acids and glycerol. They can also be used to analyze monoacylglycerol (MAG) levels in serum and food. The MAGL gene from strain HTA426 was artificially synthesized and heterologously expressed in Escherichia coli BL21(DE3). The recombinant His-tag fused MAGL (GkMAGL) was purified using a Ni2+-affinity column. The purified enzyme showed a temperature optimum at 65 °C and was stable up to 75 °C after 30 min incubation. In addition, the enzyme exhibited a pH optimum of 7.5 and was stable from pH 5.0 to 11.0. The enzyme hydrolyzed monoacylglycerols and showed the highest activity toward 1-monolauroylglycerol. The enzyme was stable in the presence of various organic solvents and detergents. The addition of Triton X-100 significantly increased GkMAGL activity. The thermal stability of the enzyme was higher than that of thermostable MAGL from Geobacillus sp. 12AMOR1 (12AMOR1_MAGL). Circular dichroism spectral analysis showed that the conformational stability of the GkMAGL was higher than that of 12AMOR1_MAGL at higher temperatures. These results indicate that the GkMAGL has useful features that can be used for various biotechnological applications.

Ex vivo lipidomics reveal monoacylglycerols as substrates for a fatty acid amide hydrolase in the legume Medicago truncatula.

Fatty acid amide hydrolase (FAAH) is a conserved hydrolase in eukaryotes with promiscuous activity toward a range of acylamide substrates. The native substrate repertoire for FAAH has just begun to be explored in plant systemsoutside the model Arabidopsis thaliana. Here, we used ex vivo lipidomics to identify potential endogenous substrates for Medicago truncatula FAAH1 (MtFAAH1). We incubated recombinant MtFAAH1 with lipid mixtures extracted from M. truncatula and resolved their profiles via gas chromatography-mass spectrometry (GC-MS). Data revealed that besides N-acylethanolamines (NAEs), sn-1 or sn-2 isomers of monoacylglycerols (MAGs) were substrates for MtFAAH1. Combined with in vitro and computational approaches, our data support both amidase and esterase activities for MtFAAH1. MAG-mediated hydrolysis via MtFAAH1 may be linked to biological roles that are yet to be discovered.

Distribution and Level of Bioactive Monoacylglycerols in 12 Marine Microalgal Species.

Microalgae are currently considered an attractive source of highly valuable metabolites potentially exploitable as anticancer agents, nutraceuticals and cosmeceuticals and for bioenergy purposes. Their ease of culturing and their high growth rates further promote their use as raw material for the production of specialty products. In the present paper, we focused our attention on specific glycerol-based lipid compounds, monoacylglycerols (MAGs), which displayed in our previous studies a selective cytotoxic activity against the haematological U-937 and the colon HCT-116 cancer cell lines. Here, we performed a quali/quantitative analysis of MAGs and total fatty acids (FAs) along with a profiling of the main lipid classes in a panel of 12 microalgal species, including diatoms and dinoflagellates. Our results highlight an inter- and intraspecific variability of MAG profile in the selected strains. Among them, Skeletonema marinoi (strain FE7) has emerged as the most promising source for possible biotechnological production of MAGs.

Rapeseed oleogels based on monoacylglycerols and methylcellulose hybrid oleogelators: Physicochemical and rheological properties

In this study, we investigated the combined impact of monoacylglycerol (MAGs) and methylcellulose (MC) on the production of hybrid oleogels. Since cellulose derivatives are inherently hydrophilic substances, they require dissolution in oil through an emulsion-coating method. Therefore, we developed a hybrid oleogel utilizing MAGs and MC. Initially, a hybrid oleogelator was created by blending an aqueous MC solution into fully melted MAGs to form MC in water-in-MAGs emulsions with varying MC/MAG ratios, followed by drying. Subsequently, the resulting oleogelator was mixed with rapeseed oil to produce oleogels, and their properties were compared with oleogels produced solely with MAG oleogelator. The findings indicated that the obtained oleogelator did not significantly impact the oxidation of the oleogels. Additionally, there was no notable difference observed in the induction period of crystallization and the crystallization rate of the oleogels. Microscopic images revealed that the hybrid oleogel structured with a 30:70 ratio of MAGs and MC contained the lowest liquid phase percentage. In terms of rheological assessment, the hybrid oleogels exhibited solid-like behavior, consistent with polarized light microscopy (PLM) images. Furthermore, based on the three-interval thixotropic test (3-ITT), the hybrid oleogels displayed higher recovery compared to the control sample.

Multiple-stage silica-assisted liquid-liquid extraction: A promising extraction method for fractionation Mono-diacylglycerols(MDAGs) based Palm Stearin

Palm stearin-based mono-diacylglycerols (MDAGs) are food emulsifiers that have not yet been widely developed. Monoacylglycerol (MAG) and diacylglycerol (DAG) are the predominant components of MDAGs. Fractionation of MDAGs into MAG and DAG was currently performed by molecular distillation, chromatography, crystallisation or supercritical CO2. In order to reduce production costs and increase production efficiency, a simpler technique for MDAG fractionation is required. A ternary diagram was used to determine the optimum solvent composition for the extraction of MDAGs. Three different extraction methods, i.e. solid-liquid extraction, liquid-liquid extraction and multiple-stage silica-assisted liquid-liquid extraction, were used to fractionate MDAGs. The multiple-stage silica-assisted liquid-liquid extraction provides better separation performance than solid-liquid and liquid-liquid extraction. The extraction method with hexane solvent composition was able to produce DAG-rich fractions with a purity of 81.05% DAG and 16.47% MAG, while the binary solvent composition of hexane:ethanol (8:2) was able to produce MAG-rich fractions with a purity of 13.33% DAG and 83.45% MAG. This extraction method combines two separation mechanisms, i.e. adsorption on silica and solubility in the corresponding solvent. The latter method has the potential for production MAG-rich fraction and DAG-rich fraction. According to their respective functions, each of these fractions can be further developed.

Faecal lipid profile as a new marker of fat maldigestion, malabsorption and microbiota.

Fat malabsorption in children with cystic fibrosis (CF) leads to poor nutritional status and altered colonic microbiota. This study aimed at establishing the faecal lipid profile in children with CF, and exploring associations between the faecal lipidome and microbiota. Cross-sectional observational study with children with CF and an age-matched control group. Faecal lipidome was analysed by UHLC-HRMS and microbiota profiling by 16S rRNA amplicon sequencing. Among 234 identified lipid species, five lipidome clusters (LC) were obtained with significant differences in triacylglycerols (TG), diacylglycerols (DG), monoacylglycerols (MG) and fatty-acids (FA): LC1 subjects with good digestion and absorption: low TG and low MG and FA; LC2 good digestion and poor absorption: low TG and high MG and FA; LC3 Mild digestion and poor absorption: intermediate TG and high MG and FA; LC4 poor digestion and absorption: high TG and high MG and FA; LC5 outliers. Bacteroidota and Verrucomicrobiota decreased over LC1-LC4, while Proteobacteria increased. Nutritional status indicators were significantly higher in LC1 and decreased over LC2-LC4. Assessing faecal lipidome may be relevant to determine how dietary lipids are digested and absorbed. This new evidence might be a method to support targeted nutritional interventions towards reverting fat maldigestion or malabsorption. Lipidomic analysis enabled the identification of the lipid species related to maldigestion (triglycerides) or malabsorption (monoglycerides and fatty acids). Children with cystic fibrosis can be grouped depending on the faecal lipidome profile related to dietary fat maldigestion or malabsorption. The lipidome profile in faeces is related to the composition of microbiota and nutritional status indicators.

Thermoreversible oleogelation of fatty acid monoglyceride-containing sunflower oil from a rheological approach

Nowadays, there is a growing concern among consumers about the impact of diet on health. In this regard, oleogelation has been proposed as a promising strategy to replace unhealthy fats, as well as to encapsulate water-insoluble bioactive compounds in food matrices. Consequently, the development of thermoreversible oleogels may play an important role in the bioavailability and biostability of functional foods and the beneficial effects associated with them. The aim of this work was to evaluate the viscoelastic behavior of oleogels using a commercial food additive (E471) composed of fatty acid monoglycerides (MG). Furthermore, the study of sol-gel transitions of these thermoreversible oleogels allowed to obtain the optimum concentration of gelling agent required. Refined sunflower oil containing 2–5 wt% of E471 were characterized by means of SAOS tests, as a function of temperature. All these systems were liquids above 48 °C, forming stable oleogels below 20 °C. An improvement of the elastic component of them was observed as gelling agent concentration was higher. Oleogels containing 4 and 5 wt% MG showed very similar viscoelastic properties and high stability at body temperature (ca. 37 °C). Conversely, systems containing 2% or 3% led to the formation of weaker gels exhibiting thermo-reversibility but only the latter was stable at body temperature. Therefore, sunflower oleogels containing MG above 3 wt% could be regarded as potential carrier food matrices for lipid-soluble active ingredients. To this end, the modulation of the oleogel network consistency should play a key role in maintaining the integrity of the active principle during gastrointestinal transit.

Effect of monoglyceride on crystallization behavior and physical properties of cottonseed oil stearin

Slow crystallization-rate, low SFC and nonuniform mushy texture at ambient temperature hinder the application of cottonseed oil stearin (COS) in plastic fat products. Adding emulsifiers is usually used to overcome these drawbacks by modifying the crystallization of COS. In this study, different levels of commercial monoglycerides (MGs) were added to the COS, and the crystallization behavior, crystal microstructure and physical properties of the COS/MG were investigated. The addition of MGs promoted the crystallization of the COS significantly, modified the crystal subcell structure of COS and contributed to the development of the co-crystalliaztion of MG and the high melting point TGs of COS. A new crystal cluster (sphere-shaped and compact crystal clusters) was observed in COS/MG blends, which might have a relation with the co-crystallization of MG and high melting triglycerides (TGs) of COS. With the increase of MG level in the COSs, the crystalline network become denser. Further, the SFC and the rheological properties (including the viscoelasticity, the resistance to heat and shear force) of COS/MG blends improved by adding MG. The possible crystallization mechanisms were proposed to understand the effects of MG on the crystallization microstructure and rheological properties of COS.

The relationship between nonlinear viscoelasticity and baking performance in low-saturated puff pastry margarine

The oil phase obtained by blending and oleogel methods has potential for the production of non‑hydrogenated and low-saturated puff pastry margarine, thereby reducing intakes of both types of dietary fat. The crystal form, microstructure, rheology, and baking applications of puff pastry margarines prepared with anhydrous milk fat (AMF)/palm stearin (POs), POs/palm oil (PO), beef tallow (BT)/PO, or AMF/POs/diacetyl tartaric acid ester of mono(di)glycerides (DATEM) oleogels were investigated using X-ray scattering, polarized light microscope, and rheometer, respectively. All margarines exhibited β’-form crystal and strongly viscoelastic at low strain. With the addition of DATEM oleogel, their crystal microstructure became more uniform and finer, and the croissants were less hard (1690) and chewiness (160). The chewiness of croissants produced using the margarines was significantly improved with POs content. The theoretical basis for preparation and application in non‑hydrogenated and low-saturated puff pastry margarine was provided in the present study.

Structuring PUFA-rich oils with monoglycerides: Physicochemical and nutritional properties of fat substitutes with high-lipid quality

Driven by the demand for semisolid lipid materials with low saturated fatty acid (SFA) content and high-nutritional profiles, monoglyceride (MG) oleogels were produced using oils rich in polyunsaturated fatty acids (PUFA), i.e. fatty acids that are themselves bioactive compounds. The effects of the MG concentration (6% and 10%, w/w) and oil type—sunflower, chia, flaxseed, soybean, and sesame—on nutritional and structural, rheological, mechanical, and thermal properties of oleogels were investigated. Overall, all oleogels were structurally stable gels with textural characteristics that can mimic the functionality of spreadable margarines. In addition, by changing the oil type and MG concentration, the properties studied could be tailored. Particularly, chia and flaxseed oleogels, exhibiting superior nutritional quality based on their low atherogenic and thrombogenic indexes and higher PUFA/SFA ratios, showed the highest hardness (up to 48% higher) and oil binding capacity (OBC). This enhanced functionality was attributed to their microstructural characteristics, featuring smaller crystals, and the unrefined nature of these oils. Notably, flaxseed oleogels with 6% MG yielded OBC values of 99.5%, similar to all samples containing 10% MG. Furthermore, results from a low-temperature Rancimat test suggested that MG crystalline structure may protect chia oil against oxidation. Our findings indicate that PUFA-rich oils have potential for developing health-conscious ingredients with acceptable technological characteristics.