The Production, Benefits, and Applications of Monoacylglycerols and Diacylglycerols of Nutritional Interest

Molecular docking simulation reveals the lipase-substrate binding mechanism in the enzymatic synthesis of diacylglycerol-enriched vegetable oils

Diacylglycerol (DAG) is a functional lipid that is naturally present in vegetable oils in limited concentrations (1 %-5 %). This study proposed an enzymatic method to afford high-content-DAG vegetable oils via a reaction catalyzed by an immobilized lipase, PS@OMS-C8, using high-speed homogenization and molecular distillation. Results indicated that 48.6 % DAG was initially obtained through the enzymatic glycerolysis of rapeseed oil with glycerol, of which 90.2 % was sn-1,3-DAG. PS@OMS-C8 maintained 35.5 % DAG content after 10 reuse cycles, confirming its catalytic stability; this was attributed to lipase immobilization on the ordered mesoporous silica that significantly improve the secondary protein structures, including α-helix and β-sheet, thereby strengthening the rigidity of PS@OMS-C8. In addition to producing DAG-enriched rapeseed oil, other edible oils with 39.4 %-50.2 % DAG content were obtained, as revealed via molecular docking simulation. This study offers new strategies for the sustainable synthesis of vegetable oils with a high content of functional lipids high-content functional lipids.

Biocatalytic Preparation of High-Purity DHA-Enriched Partial Glycerides through Semirational Design and Modification of Lipase Lip1897

High-purity docosahexaenoic acid (DHA) partial glycerides (PG) supplements have promising market prospects. In this study, a novel lipolytic enzyme family I lipase Lip1897, derived from Streptomyces thermodiastaticus, was identified and modified to be applied to the enzymatic synthesis of high-purity docosahexaenoic acid partial glycerides (DHA-PG). Lip1897 displayed optimal activity and good stability at 55 °C and pH 5.0. Further study found that Lip1897 could catalyze the hydrolysis of DHA triglycerides (TG) and DHA ethyl esters (EE), the esterification of DHA, and the glycerolysis of docosahexaenoic acid ethyl esters (DHA-EE), which had good prospects for industrial application. To enhance the catalytic selectivity of Lip1897, semirational design and modification based on structural analysis were carried out, and the mutant Lip1897-H106W showed a 1.86-fold increase in glycerolysis activity. The molecular docking results indicated that the mutant bound to the substrate DHA-EE at lower energy and with a more stable conformation. Under the solvent-free system, Lip1897-H106W was employed to catalyze the glycerolysis of DHA-EE for the synthesis of DHA-PG, achieving a promising DHA-EE conversion rate of 95.02% and a high DHA-PG yield of 70.85%. The efficient glycerolysis for preparing high-purity DHA-PG was realized. This research provides a reference for enhancing the efficiency of specific configurational functional lipid biosynthesis through enzyme discovery and modification.

Interfacial modulation of hierarchically porous UIO-66 for the immobilization of Rhizomucor miehei lipase towards the efficient synthesis of 1,3-dioleic acid glycerol

Herein, UiO-66 was selected as the immobilization carrier of Rhizomucor miehei lipase (RML). After etching and hydrophobic modification, the functionalized UIO-66 (H-UIO-66-OPA) was utilized for RML immobilization and the obtained RML@H-UIO-66-OPA showed about 70 % relative activity after incubation at 60 °C, which was much better than RML (20 %). RML@H-UIO-66-OPA was used in the synthesis of 1,3-dioleic acid glycerol (1,3-DAG) and the effects of reaction conditions (temperature, enzyme addition, substrate molar ratio, and time) on 1,3-DAG yield were investigated. Under the optimal conditions (temperature of 65 °C, enzyme addition of 2 wt%, substrate molar ratio of 2:1, and reaction time of 4 h), 1,3-DAG yield reached 77 %. Finally, Box-Behnken experimental design method was utilized to optimize the process parameters for the preparation of 1,3-DAG, and the final 1,3-DAG content was 79.80 %, which demonstrated that the model could predict the relationship between the factors and be suitable for the process optimization in 1,3-DAG preparation.

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.

Structured Lipids Engineering for Health: Novel Formulations Enriched in n-3 Long-Chain Polyunsaturated Fatty Acids with Potential Nutritional Benefits

Structured lipids (SLs) offer a promising avenue for designing novel formulations enriched in n-3 long-chain polyunsaturated fatty acids (LCPUFAs) with potential health benefits. Triacylglycerols (TAGs), the most common fats in the human diet, are both non-toxic and chemically stable. The metabolic efficiency and digestibility of TAGs are significantly influenced by the position of fatty acids (FAs) within the glycerol backbone, with FAs at the sn-2 position being readily absorbed. Over the past two decades, advancements in SL research have led to the development of modified TAGs, achieved either through chemical or enzymatic processes, resulting in SLs. The ideal structure of SLs involves medium-chain FAs at the sn-1,3 positions and long-chain n-3 LCPUFAs at the sn-2 position of the glycerol backbone, conferring specific physicochemical and nutritional attributes. These tailored SL formulations find wide-ranging applications in the food and nutraceutical industries, showing promise for dietary support in promoting health and mitigating various diseases. In particular, SLs can be harnessed as functional oils to augment TAG metabolism, thereby impeding the development of fatty liver, countering the onset of obesity, and preventing atherosclerosis and age-related chronic diseases. In scrutinising prevailing research trajectories, this review endeavours to provide an in-depth analysis of the multifaceted advantages and repercussions associated with the synthesis of SLs. It elucidates their burgeoning potential in enhancing health and well-being across a range of demographic cohorts. Specifically, the implications of SL utilisation are discussed in the context of healthcare environments and early childhood developmental support.

Acyl migration of 2-monoacylglycerols rich in DHA: Effect of temperature and solvent medium

Acyl migration of 2-monoacylglycerols (2-MAGs) rich in DHA is a universal reaction occurring during storage and structural lipid synthesis, and affects their nutritional value. In this study, their acyl migration was investigated under different systems and temperatures. The enhanced temperature promoted acyl migration, leading to a 5.6-fold increase from 20 °C to 50 °C. The kinetic study indicated rate constants followed the order: hexane > solvent-free > dichloromethane > ethanol ≈ acetone ≈ acetonitrile > t-butanol, and positively correlated with log P of solvent. During acyl migration in ethanol, acetone, acetonitrile and t-butanol at 40 °C, DHA content in 2-MAGs was higher than in 1-MAGs, indicating slow acyl migration of DHA; while at 50 °C, the difference of DHA distribution was small, due to increasing acyl migration rate. The results suggest that acyl migration of different fatty acids can be regulated by changing conditions to enrich DHA at sn-2 position.

Solid Lipid Nanoparticles: Review of the Current Research on Encapsulation and Delivery Systems for Active and Antioxidant Compounds

Various active compounds are easily damaged, so they need protection and must be easily absorbed and targeted. This problem can be overcome by encapsulating in the form of solid lipid nanoparticles (SLNs). Initially, SLNs were widely used to encapsulate hydrophobic (non-polar) active compounds because of their matched affinity and interactions. Currently, SLNs are being widely used for the encapsulation of hydrophilic (polar) and semipolar active compounds, but there are challenges, including increasing their entrapment efficiency. This review provides information on current research on SLNs for encapsulation and delivery systems for active and antioxidant compounds, which includes various synthesis methods and applications of SLNs in various fields of utilization. SLNs can be developed starting from the selection of solid lipid matrices, emulsifiers/surfactants, types of active compounds or antioxidants, synthesis methods, and their applications or utilization. The type of lipid used determines crystal formation, control of active compound release, and encapsulation efficiency. Various methods can be used in the SLN fabrication of active compounds and hydrophilic/hydrophobic antioxidants, which have advantages and disadvantages. Fabrication design, which includes the selection of lipid matrices, surfactants, and fabrication methods, determines the characteristics of SLNs. High-shear homogenization combined with ultrasonication is the recommended method and has been widely used because of the ease of preparation and good results. Appropriate fabrication design can produce SLNs with stable active compounds and antioxidants that become suitable encapsulation systems for various applications or uses.

Future of Structured Lipids: Enzymatic Synthesis and Their New Applications in Food Systems

Structured lipids (SLs) refer to a new type of functional lipid obtained by modifying natural triacylglycerol (TAG) through the restructuring of fatty acids, thereby altering the composition, structure, and distribution of fatty acids attached to the glycerol backbones. Due to the unique functional characteristics of SLs (easy to absorb, low in calories, reduced serum TAG, etc.), there is increasing interest in the research and application of SLs. SLs were initially prepared using chemical methods. With the wide application of enzymes in industries and the advantages of enzymatic synthesis (mild reaction conditions, high catalytic efficiency, environmental friendliness, etc.), synthesis of SLs using lipase has aroused great interest. This review summarizes the reaction system of SL production and introduces the enzymatic synthesis and application of some of the latest SLs discussed/developed in recent years, including medium- to long-chain triacylglycerol (MLCT), diacylglycerol (DAG), EPA- and DHA-enriched TAG, human milk fat substitutes, and esterified propoxylated glycerol (EPG). Lastly, several new ways of applying SLs (powdered oil, DAG plastic fat, inert gas spray oil, and emulsion) in the future food industry are also highlighted.

Efficacy and durability of bovine virus diarrhea (BVD) virus killed vaccine adjuvanted with monolaurin

The bovine virus diarrhea virus (BVDV) causes reproductive, enteric, and respiratory diseases. Vaccination is essential in increasing herd resistance to BVDV spread. The selection of an adjuvant is an important factor in the success of the vaccination process. Monolaurin or glycerol monolaurate is a safe compound with an immunomodulatory effect. This study aimed to evaluate the efficacy of monolaurin as a novel adjuvant. This was examined through the preparation of an inactivated BVDV (NADL strain) vaccine adjuvanted with different concentrations of monolaurin and compared with the registered available locally prepared polyvalent vaccine (Pneumo-4) containing BVD (NADL strain), BoHV-1 (Abou Hammad strain), BPI3 (strain 45), and BRSV (strain 375L), and adjuvanted with aluminum hydroxide gel. The inactivated BVDV vaccine was prepared using three concentrations, 0.5%, 1%, and 2%, from monolaurin as adjuvants. A potency test was performed on five groups of animals. The first group, which did not receive vaccination, served as a control group while three other groups were vaccinated using the prepared vaccines. The fifth group received the Pneumo-4 vaccine. Vaccination response was monitored by measuring viral neutralizing antibodies using enzyme-linked immunosorbent assay (ELISA). It was found that the BVD inactivated vaccine with 1% and 2% monolaurin elicited higher neutralizing antibodies that have longer-lasting effects (nine months) with no reaction at the injection site in comparison to the commercial vaccine adjuvanted by aluminum hydroxide gel.

Sodium Silicate Catalyst for Synthesis Monoacylglycerol and Diacylglycerol-Rich Structured Lipids: Product Characteristic and Glycerolysis–Interesterification Kinetics

Sodium silicate as heterogeneous base catalysts is more environmentally friendly and easily separated by filtration. The objective of this research was to evaluate the activated sodium silicate as catalyst for synthesis of monoacylglycerol (MAG) and diacylglycerol (DAG)-rich structured lipids (SLs) from a palm olein-stearin blend. Sodium silicate was activated and functional group was characterized. Reaction was performed using 5% catalyst (w/w) at various reaction temperature (70–120 °C) for 3 h in a batch stirred tank reactor. Physical properties of SLs, such as melting point, slip melting point, and hardness of SLs were determined. Reaction kinetics were also evaluated. The results show that Si−O bending was reduced and shifted to a Si−O−Na and Si−O−Si functional groups after sodium silicate activation. Temperature had a significant effect on SLs composition at higher than 90 °C. An increase in temperature produced more MAG, resulting in better product physical properties. The best reaction condition was at 110 °C. Rate constants and the Arrhenius equation were also obtained for each reaction step. In summary, the activated sodium silicate catalyzed glycerolysis-interesterification reaction, which produced MAG and DAG at temperature higher than 90 °C. Therefore, the physical properties of SLs were improved. Copyright © 2022 by Authors, Published by BCREC Group. This is an open access article under the CC BY-SA License (https://creativecommons.org/licenses/by-sa/4.0). 

Biomolecular characterisation of marine microalga in comparison to fishmeal and soymeal as an alternative feed ingredient

INTRODUCTION

Marine microalgae protein has better solubility and digestibility than other protein-based feeds. Apart from protein, high-value biomolecules have an immense potential to enhance the quality of feed, but knowledge about them is scarce.

OBJECTIVE

Marine microalga Picochlorum sp. biomass molecular characterisation along with commonly used protein feed such as fishmeal and soymeal for potential feed ingredients.

METHODOLOGY

Liquid chromatography coupled with mass spectrometry (LC-MS) was used for biomolecular characterisation. The correlation of biomolecules sets was evaluated using principal component analysis (PCA) and heatmap clustering.

RESULTS

LC-MS identified 116 biomolecules cumulatively among microalga, fishmeal, and soymeal that includes fatty acids, acylglycerols, vitamins, sterols, pigments, nucleotides, unique amino acids, amines, sugars and miscellaneous. These 116 biomolecules were screened based on their functional importance as feed ingredients. Among the different sets of biomolecules, microalga contained a more diverse set of fatty acids, pigments, sterols, and vitamins than acylglycerols, unique amino acids, nucleotides, and sugars. Fishmeal contained a more diverse set of acylglycerols, unique amino acids, nucleotides, and amines, while soymeal contained the highest number of sugars and miscellaneous biomolecules. The PCA confirmed the significance level (P > 95%) and heatmap clustering showed the diversity and relatedness of biomolecules among the microalga, fishmeal, and soymeal.

CONCLUSION

This study showed that the marine microalga Picochlorum sp. biomass has a rich source of biomolecules and could complement fishmeal or soymeal in feed and is also sustainable and economical as compared to fishmeal and soymeal.

Roles of Endocannabinoids and Endocannabinoid-like Molecules in Energy Homeostasis and Metabolic Regulation: A Nutritional Perspective

The endocannabinoid system is involved in signal transduction in mammals. It comprises principally G protein-coupled cannabinoid receptors and their endogenous agonists, called endocannabinoids, as well as the enzymes and transporters responsible for the metabolism of endocannabinoids. Two arachidonic acid-containing lipid molecules, arachidonoylethanolamide (anandamide) and 2-arachidonoylglycerol, function as endocannabinoids. N-acylethanolamines and monoacylglycerols, in which the arachidonic acid chain is replaced with a saturated or monounsaturated fatty acid, are not directly involved in the endocannabinoid system but exhibit agonistic activities for other receptors. These endocannabinoid-like molecules include palmitoylethanolamide, oleoylethanolamide (OEA), and 2-oleoylglycerol. Endocannabinoids stimulate feeding behavior and the anabolism of lipids and glucose, while OEA suppresses appetite. Both central and peripheral systems are included in these nutritional and metabolic contexts. Therefore, they have potential in the treatment and prevention of obesity. We outline the structure, metabolism, and biological activities of endocannabinoids and related molecules, and focus on their involvement in energy homeostasis and metabolic regulation. Expected final online publication date for the Annual Review of Nutrition, Volume 41 is September 2021. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.

Quality of Emulsions Containing Fat Blends Modified by Enzymatic Catalysis

The purpose of this study was to evaluate the effect of the enzymatic modification of muton tallow and hemp seed oil fat blends. An attempt of application of these fat blends as fat phases in emulsion systems with various amount of carboxymethylcellulose was made. Fat blends before and after enzymatic catalysis were assessed in the context of polar and non-polar fractions content, antioxidant activity, oxidative stability and texture. Emulsions were investigated in the terms of their stability, color, microstructure, droplets diameter, and viscosity. The study revealed that emulsions containing as a fat phases modified blends with greater share of mutton tallow showed more favorable properties, and greater stability. The presented emulsions are a model dispersion system, after adjustment of the additives they could be used as chemical, food or cosmetic products.

Green technologies for production of oils rich in n-3 polyunsaturated fatty acids from aquatic sources

Fish and algae are the major sources of n-3 polyunsaturated fatty acids (n-3 PUFAs). Globally, there is a rapid increase in demand for n-3 PUFA-rich oils. Conventional oil production processes use high temperature and chemicals, compromising the oil quality and the environment. Hence, alternative green technologies have been investigated for producing oils from aquatic sources. While most of the studies have focused on the oil extraction and enrichment of n-3 PUFAs, less effort has been directed toward green refining of oils from fish and algae. Enzymatic processing and ultrasound-assisted extraction with environment-friendly solvents are the most promising green technologies for extracting fish oil, whereas pressurized extractions are suitable for extracting microalgae oil. Lipase-catalysed ethanolysis of fish and algae oil is a promising green technology for enriching n-3 PUFAs. Green refining technologies such as phospholipase- and membrane-assisted degumming deserve investigation for application in fish and algal oils. In the current review, we critically examined the currently existing research on technologies applied at each of the steps involved in the production of oils rich in n-3 PUFAs from fish and algae species. Special attention was placed on assessment of green technologies in comparison with conventional processing methods.

Investigation of enhanced oxidation stability of microencapsulated enzymatically produced tuna oil concentrates using complex coacervation

Tuna oil was selectively hydrolysed using Thermomyces lanuginosus lipase for 6 h to prepare omega-3 acylglycerol concentrate with the DHA content significantly increased from 24.9% in tuna oil to 36.3% in the acylglycerol concentrate. The acylglycerol concentrate was subsequently encapsulated into the "multi-core" microcapsules using gelatin-sodium hexametaphosphate complex coacervates as the shell material. Rancimat, Oxipres and thermogravimetric analyses all showed that the microencapsulated acylglycerol concentrate had unexpectedly improved oxidation stability, compared to those produced using tuna oil, even though the concentrated oils themselves were significantly less stable than tuna oil. The incorporation of enzymatic tuna oil acylglycerol concentrate also significantly improved the oxidation stability of microencapsulated standard refined unconcentrated tuna oil. A wide range of characteristics including lipid and fatty acid composition, oil-in-water (O/W) emulsion properties, morphology, nanomechanical strength and physicochemical stability of acylglycerol, acylglycerol oil-in-water (O/W) emulsion and final microcapsules were investigated throughout the preparation. The result suggests that high levels of monoacylglycerol (about 35%) and diacylglycerol (about 8.5%) were produced in the acylglycerol. The acylglycerol O/W emulsion exhibited significantly smaller droplet size, lower zeta-potential and higher surface hydrophobicity, which contributed to the formation of the microcapsule with a significantly smoother surface and more compact structure, finally leading to improved oxidative stability compared to those prepared from native tuna oil.

Rhizopus oryzae Lipase, a Promising Industrial Enzyme: Biochemical Characteristics, Production and Biocatalytic Applications

Lipases are biocatalysts with a significant potential to enable a shift from current pollutant manufacturing processes to environmentally sustainable approaches. The main reason of this prospect is their catalytic versatility as they carry out several industrially relevant reactions as hydrolysis of fats in water/lipid interface and synthesis reactions in solvent-free or non-aqueous media such as transesterification, interesterification and esterification. Because of the outstanding traits of Rhizopus oryzae lipase (ROL), 1,3-specificity, high enantioselectivity and stability in organic media, its application in energy, food and pharmaceutical industrial sector has been widely studied. Significant advances have been made in the biochemical characterisation of ROL particularly in how its activity and stability are affected by the presence of its prosequence. In addition, native and heterologous production of ROL, the latter in cell factories like Escherichia coli, Saccharomyces cerevisiae and Komagataella phaffii (Pichia pastoris), have been thoroughly described. Therefore, in this review, we summarise the current knowledge about R. oryzae lipase (i) biochemical characteristics, (ii) production strategies and (iii) potential industrial applications.

Continuous Flow Upgrading of Selected C2-C6 Platform Chemicals Derived from Biomass

The ever increasing industrial production of commodity and specialty chemicals inexorably depletes the finite primary fossil resources available on Earth. The forecast of population growth over the next 3 decades is a very strong incentive for the identification of alternative primary resources other than petro-based ones. In contrast with fossil resources, renewable biomass is a virtually inexhaustible reservoir of chemical building blocks. Shifting the current industrial paradigm from almost exclusively petro-based resources to alternative bio-based raw materials requires more than vibrant political messages; it requires a profound revision of the concepts and technologies on which industrial chemical processes rely. Only a small fraction of molecules extracted from biomass bears significant chemical and commercial potentials to be considered as ubiquitous chemical platforms upon which a new, bio-based industry can thrive. Owing to its inherent assets in terms of unique process experience, scalability, and reduced environmental footprint, flow chemistry arguably has a major role to play in this context. This review covers a selection of C₂ to C₆ bio-based chemical platforms with existing commercial markets including polyols (ethylene glycol, 1,2-propanediol, 1,3-propanediol, glycerol, 1,4-butanediol, xylitol, and sorbitol), furanoids (furfural and 5-hydroxymethylfurfural) and carboxylic acids (lactic acid, succinic acid, fumaric acid, malic acid, itaconic acid, and levulinic acid). The aim of this review is to illustrate the various aspects of upgrading bio-based platform molecules toward commodity or specialty chemicals using new process concepts that fall under the umbrella of continuous flow technology and that could change the future perspectives of biorefineries.

Immobilization of lipase Eversa Transform 2.0 on poly(urea-urethane) nanoparticles obtained using a biopolyol from enzymatic glycerolysis

In this work, the free lipase Eversa^® Transform 2.0 was used as a catalyst for enzymatic glycerolysis reaction in a solvent-free system. The product was evaluated by nuclear magnetic resonance (¹H NMR) and showed high conversion related to hydroxyl groups. In sequence, the product of the glycerolysis was used as stabilizer and biopolyol for the synthesis of poly(urea-urethane) nanoparticles (PUU NPs) aqueous dispersion by the miniemulsion polymerization technique, without the use of a further surfactant in the system. Reactions resulted in stable dispersions of PUU NPs with an average diameter of 190 nm. After, the formation of the PUU NPs in the presence of concentrated lipase Eversa^® Transform 2.0 was studied, aiming the lipase immobilization on the NP surface, and a stable enzymatic derivative with diameters around 231 nm was obtained. The hydrolytic enzymatic activity was determined using ρ-nitrophenyl palmitate (ρ-NPP) and the immobilization was confirmed by morphological analysis using transmission electron microscopy and fluorescence microscopy.

Synthesis, physicochemical properties, and health aspects of structured lipids: A review

Structured lipids (SLs) refer to a new type of functional lipids obtained by chemically, enzymatically, or genetically modifying the composition and/or distribution of fatty acids in the glycerol backbone. Due to the unique physicochemical characteristics and health benefits of SLs (for example, calorie reduction, immune function improvement, and reduction in serum triacylglycerols), there is increasing interest in the research and application of novel SLs in the food industry. The chemical structures and molecular architectures of SLs define mainly their physicochemical properties and nutritional values, which are also affected by the processing conditions. In this regard, this holistic review provides coverage of the latest developments and applications of SLs in terms of synthesis strategies, physicochemical properties, health aspects, and potential food applications. Enzymatic synthesis of SLs particularly with immobilized lipases is presented with a short introduction to the genetic engineering approach. Some physical features such as solid fat content, crystallization and melting behavior, rheology and interfacial properties, as well as oxidative stability are discussed as influenced by chemical structures and processing conditions. Health-related considerations of SLs including their metabolic characteristics, biopolymer-based lipid digestion modulation, and oleogelation of liquid oils are also explored. Finally, potential food applications of SLs are shortly introduced. Major challenges and future trends in the industrial production of SLs, physicochemical properties, and digestion behavior of SLs in complex food systems, as well as further exploration of SL-based oleogels and their food application are also discussed.

Interesterification of Soybean Oil with Propylene Glycol in Supercritical Carbon Dioxide and Analysis by NMR Spectroscopy

The time course study of high monoester mixtures from soybean oil (HMMS) synthesis, as healthier alternatives to trans food products, in a supercritical CO₂ (SCCO₂) medium with and without enzyme, was investigated. Phosphorous nuclear magnetic resonance (³¹P-NMR) was used to quantify the absolute amount of partially esterified acylglycerols (PEGs). Carbon NMR was utilized to determine the type and position of the fatty acids (FAs) of HMMS. Enzyme and time significantly influenced the synthesis of 1-monoglycerides (1-MGs), 2-MGs, and 1,2-diglycerides (1,2-DGs) in this alcoholysis of soybean oil with 1,2-propanediol, based on high catalytic activity and operational stability of Novozym 435 in SCCO₂ during short reaction time. Results suggest that 4 h is a suitable reaction time for this lipase-catalyzed interesterification (LIE) system for the synthesis of 2-MGs with a yield of 20%. The highest polyunsaturated fatty acid (PUFA) (65%) in the triglyceride (TG) of HMMS was produced after 4 h of reaction. After 6 h of reaction, a high level (20%) of saturated fatty acids (SFAs) was found in the TGs of HMMS, which were distributed between the sn-2 (5%) and sn-1, 3 (15%) positions.

Pressurized liquid extraction with ethanol as a green and efficient technology to lipid extraction of Isochrysis biomass

This work was the first time to establish a green pressurized liquid extraction (PLE) process to extract microalgal lipids from Isochrysis biomass. PLE with ethanol exhibited superior lipid extraction performance in comparison to Soxhlet and Folch methods and PLE with n-hexane. To reduce the cost in ethanol utilization, ethanol concentration was optimized and found that PLE with 90% ethanol concentration obtained the highest lipid extraction efficiency (41.5 wt%) and total fatty acids (TFAs) recovery value (92.17 wt%) using Isochrysis sp. biomass. Results about lipid class detected by TLC-FID technique showed that ethanol concentration distinctly affected the content of lipidic class during lipid extraction by PLE. Similarly, the process with 90% ethanol concentration achieved over 90 wt% of TFAs recovery values with three different Isochrysis species. Overall, PLE process mediated with ethanol was a promising approach to extract Isochrysis-derived lipids from sustainable microalgal biomass for food application.

Ultrasonic-pretreated lipase-catalyzed synthesis of medium-long-medium lipids using different fatty acids as sn-2 acyl-site donors

The current work aimed to evaluate the effect of ultrasonic treatment on the enzymatic transesterification of medium-long-medium (MLM) lipids using 2-monoacylglycerol, bearing distinct fatty acids at the sn-2 position with palmitic acid, octadecanoic acid, oleic acid, eicosapentaenoic acid, and docosahexaenoic acids as sn-2 acyl donors. The effects of ultrasonic treatment conditions, including substrate concentration, reaction temperature and time, and enzyme loading, on the insertion of fatty acids into the sn-2 acyl position of MLM lipids were investigated. The data showed that low-frequency ultrasonic treatment could remarkably improve the insertion rate of polyunsaturated fatty acid (PUFA) into the sn-2 position of MLM lipids, compared with the conventional treatment method. By increasing the ultrasonic frequency from 20 to 30 KHz, while maintaining power at 150 W, the rate of synthesis of monounsaturated fatty acid and PUFA increased from 23.7% and 26.8% to 26.6% and 32.4% (p < 0.05), respectively. Moreover, ultrasonic treatment reduced the optimum reaction temperature from 45 to 35°C. However, the activity of Lipozyme RM-IM treated with ultrasound considerably declined from 31.10% to 26.90% (p < 0.05) after its fourth cycle, which was lower than that without ultrasonic treatment. This work provokes new routes for the utilization of ultrasonic technology in the synthesis of MLM lipids using different fatty acids as sn-2 acyl donors.

Enzymatic glycerolysis-interesterification of palm stearin-olein blend for synthesis structured lipid containing high mono- and diacylglycerol

The objective of this research was to evaluate enzymatic glycerolysis-interesterification to synthesize structured lipids (SLs) containing high monoacylglycerol (MAG) and diacylglycerol (DAG) from a palm stearin-olein blend (PS-PO blend). The results showed that the optimum conditions for the solvent to fat ratio, glycerol to fat ratio, and enzyme concentration were 2:1 (v/w), 1.5:1, and 15% (w/w), respectively. The conversion rate of MAG and DAG decreased at a high glycerol to fat ratio, low solvent to fat ratio, and high enzyme concentration due to an increase in viscosity and low agitation effectiveness. The emulsion capacity and stability of the SLs were 60.19% and 96.80%, respectively. The hardness of the SLs increased about 3.1-fold. The MAG, DAG, and triacylglycerol conversion rates were 0.45, 0.48, and 1.02%/h, respectively. Thus, glycerolysis-interesterification of a PS-PO blend increased DAG and MAG concentrations and further improved the hardness, emulsion capacity, and emulsion stability of the SLs.

Investigating the Mechanism for the Enhanced Oxidation Stability of Microencapsulated Omega-3 Concentrates

Enzymatically concentrated anchovy oil (concentrate) is known to be much less stable than unconcentrated anchovy oil. However, we previously showed that concentrate surprisingly forms more stable microcapsules, when produced by complex coacervation, than does unconcentrated anchovy oil. Here we investigate the mechanism of this unexpected stability. We also investigate whether or not incorporation of concentrate can be used as an additive to improve the stability of unconcentrated anchovy oil microcapsules. Results showed that microcap stability increased as the amount of added concentrate increased. Decreased emulsion droplet size, lower positively charged zeta potential, and higher surface hydrophobicity were observed in the oil/water (O/W) emulsion, with the incorporation of concentrate in the oil phase, compared with the unconcentrated anchovy oil O/W emulsion. Both the decreased zeta potential and the increased hydrophobicity of concentrate in the mixed oil phase may improve droplet agglomeration, leading to enhanced oxidative stability of the concentrate-containing microcapsules. Decreased repulsive forces between droplets result in a more compact structure, thicker outer shell, and smoother surface, resulting in enhanced oxidation stability of the concentrate-containing microcapsules.

Fatty Acid Profile, Phytochemicals, and Other Substances in Canarium odontophyllum Fat Extracted Using Supercritical Carbon Dioxide

This study aims to identify potential phenolic compounds, terpenoids, and other phytochemicals, as well as fatty acid profile and peptides in Canarium odontophyllum (CO) oil and oleoresin, extracted using supercritical carbon dioxide. LC-ESI-MS was applied in separation and tentative identification of phytochemicals in CO oil and oleoresin. Based on the results, 11 common fatty acids and their isomers, monoglycerides, diglycerides, as well as other types of lipid, were tentatively identified in the CO oil and oleoresin. The identified fatty acids consisted of saturated fatty acids (C8-C16), monounsaturated fatty acids (C16:1 and C18:1), polyunsaturated fatty acids (C18:2, C18:3, C18:4, and C20:3), and other unclassified fatty acids. The tentatively identified phenolic compounds were phenolic acids, flavonoids, lignans, and a phenolic monoester. Triterpenes, sesquiterpenes, and apocarotenoids were the terpenoids found in CO oil and oleoresin. Besides these typical bioactives, some volatiles, aromatic compounds, peptides, and other known and unknown phytochemicals were also tentatively identified in the oil and oleoresin of CO. Some of these compounds are new compounds identified in CO oil and oleoresin, which are not found in many other fruit oils. Although CO oil and oleoresin contain a small number of phytochemicals, their contribution as antioxidants may prevent several diseases. In this study, we hypothesized that CO oleoresin contains certain types of fatty acids that render its semi-solid together with other chemical components which are not found in CO oil. This is the first study that tentatively identified fatty acids, peptides, and potential phytochemicals in CO oil and oleoresin using LC-ESI-MS.

Synthesis of 2-docosahexaenoylglycerol by enzymatic ethanolysis

Synthesis of 2-docosahexaenoylglycerol with high nutritional value was conducted by enzymatic ethanolysis of algal oil. The effects of lipase type, substrate molar ratio of algal oil to ethanol, reaction time, reaction temperature and lipase load on the content of 2-monoacylglycerols (2-MAGs) in the crude product were investigated. Under the optimal conditions, 27-31% 2-MAGs were obtained in the ethanolysis reaction. Lipozyme 435 exhibited 1,3-specific selectivity and maintained stable operational stability after 7 successive reuse cycles. The enzymatic ethanolysis catalyzed by Lipozyme 435 could both synthesize 2-MAGs and concentrate DHA. Further purification of 2-MAGs was performed with solvent extraction by 85% ethanol aqueous solution and hexane, obtaining 95% 2-MAGs in a yield of 67%. The contents of DHA in 2-MAGs product and 2-MAGs fraction were 74.76% and 75.66%, respectively, which were about 26% higher than that in the algal oil. Therefore, this method is efficient and environmental-friendly for synthesis of 2-docosahexaenoylgylcerol.

Enzymatic esterification of acylglycerols rich in omega-3 from flaxseed oil by an immobilized solvent-tolerant lipase from Actinomadura sediminis UTMC 2870 isolated from oil-contaminated soil

Polyunsaturated fatty acids (PUFAs) are essential to human health and can be produced by enzymatic esterification. Actinomadura sediminis UTMC 2870 isolated from oil-contaminated soil contained a lipase that was stable at varying pH and in various solvents, salts, and chemicals. This lipase exhibited high efficiency for omega-3 (n-3), and its production was optimized using a response surface method. Acylglycerols (AGs) rich in n-3 were produced by extraction of the free fatty acids (FFAs) from flaxseed oil, concentration of PUFAs, and enzymatic esterification by the Celite-immobilized lipase. The resulting product contained 50% (w/w) PUFAs, including 42% (w/w) α-linolenic and 9.7% (w/w) linoleic acid. The n-6/n-3 ratio in the product was 0.24, which differed markedly from the high values for this ratio in seed oils. Therefore, the A. sediminis lipase appears to be a good candidate enzyme for ester synthesis and especially for production of n-3-rich AGs for food industries.

Glyceryl 1,3-Dipalmitate Produced from Lactobacillus paracasei subspecies. paracasei NTU 101 Inhibits Oxygen-Glucose Deprivation and Reperfusion-Induced Oxidative Stress via Upregulation of Peroxisome Proliferator-Activated Receptor γ in Neuronal SH-SY5Y Cells

Glyceryl 1,3-dipalmitate (GD) purified from Lactobacillus paracasei subsp. paracasei NTU 101-fermented products has been demonstrated to possess neuroprotective properties. We determined the effect of GD on oxygen-glucose deprivation and reperfusion (OGD/R)-induced SH-SY5Y neuroblastoma cell death. GD ameliorated OGD/R-induced apoptosis by elevating the protein expression of nuclear peroxisome proliferator-activated receptor γ (PPARγ) and nuclear factor erythroid 2-related factor 2 (Nrf2), thereby attenuating reactive oxygen species (ROS) generation. Pretreatment with GD reduced nuclear factor κ-light-chain-enhancer of activated B cells (NF-κB) expression from 1.54 ± 0.27 to 0.84 ± 0.46, thereby attenuating the induction of pro-inflammatory mediators, and increased the plasma membrane Ca²⁺ ATPase (PMCA) levels from 0.81 ± 0.02 to 1.08 ± 0.06, thus reducing the levels of cytosolic Ca²⁺; this also correlated with reduced cell death. We conclude that GD prevents SH-SY5Y cells from injury after OGD/R insult, possibly by modulating oxidative stress and inflammatory response.

Purification process for MUFA- and PUFA-based monoacylglycerols from edible oils

Important health benefits have been attributed to monoacylglycerols (MAGs) due to their various physiological functions, owing to which they become candidates for use as functional foods in order to prevent the onset of certain diseases such as colon cancer. In this work, six edible oils, namely: olive, linseed, sunflower, evening primrose, DHASCO^® and ARASCO^® have been processed to obtain different MUFA- and PUFA- based MAGs. First, the oils were hydrolyzed by means of an enzymatic process using porcine pancreatic lipase and then the reaction products were fractionated by using a liquid chromatography column containing silica gel as stationary phase in order to purify the MAGs-enriched fraction. A second chromatography process was performed using silver nitrate coated silica gel as stationary phase, in order to obtain the different MUFA- and PUFA-based MAGs from the corresponding oils. Overall, MAGs based on oleic, linoleic, α-linolenic, γ-linolenic, arachidonic and docosahexaenoic acids have been isolated in high yields and purities (92.6, 97.4, 95.3, 90.9, 100 and 95.3% purity, respectively). Positional distribution was determined by means of ¹H NMR, which revealed a mix of 1(3) and 2-MAGs in variable proportions in the different MAGs.