Review on the Current State of Diacylglycerol Production Using Enzymatic Approach

Nonconventional Technologies in Lipid Modifications

Lipid modifications play a crucial role in various fields, including food science, pharmaceuticals, and biofuel production. Traditional methods for lipid modifications involve physical and chemical approaches or enzymatic reactions, which often have limitations in terms of specificity, efficiency, and environmental impact. In recent years, nonconventional technologies have emerged as promising alternatives for lipid modifications. This review provides a comprehensive overview of nonconventional technologies for lipid modifications, including high-pressure processing, pulsed electric fields, ultrasound, ozonation, and cold plasma technology. The principles,mechanisms, and advantages of these technologies are discussed, along with their applications in lipid modification processes. Additionally, the challenges and future perspectives of nonconventional technologies in lipid modifications are addressed, highlighting the potential and challenges for further advancements in this field. The integration of nonconventional technologies with traditional methods has the potential to revolutionize lipid modifications, enabling the development of novel lipid-based products with enhanced functional properties and improved sustainability profiles.

Influence of 1,3-diacylglycerol on physicochemical and digestion properties of nanoemulsions and its enhancement of encapsulation and bioaccessibility of hydrophobic nobiletin

Lipid-based delivery systems are commonly used to encapsulate hydrophobic bioactive compounds for enhancing their bioaccessibility and bioavailability, especially for triacylglycerol (TAG) oil-based delivery systems. However, studies on the development of 1,3-diacylglycerol (DAG) oil-based delivery systems are rather limited. Herein, the influence of 1,3-DAG oil as a carrier oil on the properties of nanoemulsions and the bioaccessibility of encapsulated hydrophobic nobiletin (NOB) were investigated. High-purity 1,3-DAG (over 93% pure) was prepared by a combination of enzymatic esterification and ethanol crystallization. 1,3-DAG oil as a carrier oil could be used to formulate nanoemulsions with smaller droplet size, narrower size distribution and similar stability compared to TAG oil. Importantly, 1,3-DAG oil could efficiently encapsulate high-loading NOB (1.45 mg g-1) in nanoemulsions and significantly improve the bioaccessibility of NOB (above 80%), which is attributable to its massive lipolysis and higher encapsulation capacity than TAG oil. Moreover, the addition of the 1,3-DAG component in TAG oil significantly improved the properties of nanoemulsions and the loading and bioaccessibility of NOB, especially as the 1,3-DAG content was not less than 50%. The structure of lipids (DAG versus TAG) influenced the nanoemulsion properties and the bioaccessibility of encapsulated NOB. Based on the good properties of 1,3-DAG oil coupled with its health benefits, 1,3-DAG oil-based nanoemulsion delivery systems have great prospects for improving and extending emulsion properties and bioactivity as well as bioaccessibility enhancement.

Structure-guided preparation of fuctional oil rich in 1,3-diacylglycerols and linoleic acid from Camellia oil by combi-lipase

BACKGROUND

Diacylglycerol (DAG)-enriched oil has been attracting attention because of its nutritional benefits and biological functions, although the composition of its various free fatty acids (FFAs) and an unclear relationship between substrate and yield make it difficult to be identified and qualified with respect to its production. In the present study, linoleic acid-enriched diacylglycerol (LA-DAG) was synthesized and enriched from Camellia oil by the esterification process using the combi-lipase Lipozyme TL IM/RM IM system.

RESULTS

The relationship between FFA composition and DAG species productivity was revealed. The results showed that heterogeneous FFA with a major constituent (more than 50%) exhibited higher DAG productivity and inhibited triacylglycerol productivity compared to homogeneous constituents. Joint characterization by high-performance liquid chromatography-evaporative light scattering detection, gas chromatography-mass spectrometry and ultra-performance liquid chromatography-heated electrospray ionization-tandem mass spectrometry identified that DAG components contained dilinoleic acid acyl glyceride, linoleyl-oleyl glyceride and dioleic acid acyl glyceride in esterification products. Under the optimum conditions, 60.4% 1,3-DAG and 61.3% LA-DAG in the crude product at 1 h reaction were obtained, and further purified to 81.7% LA-DAG and 94.7% DAG via silica column chromatography.

CONCLUSION

The present study provides a guideline for the identification of DAG species, as well as a structure-guided preparation method of DAG-enriched oils via the cost-effective combi-lipase. © 2022 Society of Chemical Industry.

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.

Fabrication, characterization, and purification of nutraceutical diacylglycerol components from Camellia oil

Converting triacylgycerols (TAGs) from edible oils and fats into structured diacylglycerols (DAGs) is meaningful for reducing obesity. Camellia oil, rich in linoleic acid, has the potential to form structured linoleic acid-1,3-diacylglycerol (LA-1,3-DAG) nutrients in the industry. In this research, the physicochemical properties of modified Camellia oil (MCO) by enzymatic esterification were analyzed by Gas Chromatography-Mass Spectrometry (GC-MS), Differential Scanning Calorimetry (DSC), High Performance Liquid Chromatography-Evaporative Light Scattering Detection (HPLC-ELSD), and Ultra Performance Liquid Chromatography-Tandem Mass Spectrometry (UPLC-MS/MS). The relationship between reaction conditions and the DAG compositions is disclosed using multiple factors. It is found that high constituents of DAG increase the melting and crystallization temperature of MCO, lipase Novozym 435 gives the best yield of targeted nutrients (DAG, 1,3-DAG, LA-DAG), and the mixture of lipases, Lipozyme TL IM and Lipozyme RM IM, shows a synergistic effect in the synthetic process of DAG. Subsequently, MCO containing 65.4% DAG, 54.7% LA-DAG, and 47.6% 1,3-DAG content at optimal conditions (2% enzyme dosage, 4 h reaction time, 2.4:1 substrate molar ratio, 25.8% t-butanol as solvent, 60°C temperature) has been obtained and purified using silica column to obtain the final DAG oil containing 96.1% DAG, 64.7% 1,3-DAG, and 78.4% LA-DAG. High constituents of structured DAG oil rich in LA-1,3-DAG can be obtained by enzymatic esterification for industrial production.

Enzymatic Synthesis of Diacylglycerol-Enriched Oil by Two-Step Vacuum-Mediated Conversion of Fatty Acid Ethyl Ester and Fatty Acid From Soy Sauce By-Product Oil as Lipid-Lowering Functional Oil

Soy sauce by-product oil (SSBO), a by-product of the soy sauce production process, is the lack of utilization due to an abundance of free fatty acid (FFA) and fatty acid ethyl ester (EE). The utilization of low-cost SSBO to produce value-added diacylglycerol (DAG)-enriched oil and its applications are promising for the sustainability of the oil industry. The objective of this study was to utilize SSBO containing a high content of EE and FFA as raw material to synthesize DAG-enriched oil and to evaluate its nutritional properties in fish. Based on different behaviors between the glycerolysis of EE and the esterification of FFA in one-pot enzymatic catalysis, a two-step vacuum-mediated conversion was developed for the maximum conversions of EE and FFA to DAG. After optimization, the maximum DAG yield (66.76%) and EE and FFA conversions (96 and 93%, respectively) were obtained under the following optimized conditions: lipase loading 3%, temperature 38°C, substrate molar ratio (glycerol/FFA and EE) 21:40, a vacuum combination of 566 mmHg within the initial 10 h and 47 mmHg from the 10th to 14th hour. Further nutritional study in fish suggested that the consumption of DAG-enriched oil was safe and served as a functional oil to lower lipid levels in serum and liver, decrease lipid accumulation and increase protein content in body and muscle tissues, and change fatty acid composition in muscle tissues. Overall, these findings were vital for the effective utilization of SSBO resources and the development of future applications for DAG-enriched oil as lipid-lowering functional oil in food.

Wogonin and alleviation of hyperglycemia via inhibition of DAG mediated PKC expression. A brief insight

Protein kinase C (PKC) is a family of protein kinase enzymes that can phosphorylate other proteins and influence their functions, such as signal transduction, cell survival, and death. Increased diacylglycerol (DAG) concentrations, which are typically observed raised in hyperglycemic situations such as diabetes mellitus, can also activate PKC enzymes (DM). On the other hand, PKC isomers have been shown to play an essential role in diabetes and many hyperglycemic complications, most importantly atherosclerosis and diabetic cardiomyopathy (DCM). As a result, blocking PKC activation via DAG can prevent hyperglycemia and related consequences, such as DCM. Wogonin is a herbal medicine which has anti-inflammatory properties, and investigations show that it scavenge oxidative radicals, attenuate nuclear factor-kappa B (NF-κB) activity, inhibit several essential cell cycle regulatory genes, block nitric oxide (NO) and suppress cyclooxygenase-2 (COX-2). Furthermore, several investigations show that wogonin also attenuates diacylglycerol DAG levels in diabetic mice. Since the DAG-PKC pathway is linked with hyperglycemia and its complications, Wogonin-mediated DAG-PKC attenuation can help treat hyperglycemia and its complications.

A Valuable Product of Microbial Cell Factories: Microbial Lipase

As a powerful factory, microbial cells produce a variety of enzymes, such as lipase. Lipase has a wide range of actions and participates in multiple reactions, and they can catalyze the hydrolysis of triacylglycerol into its component free fatty acids and glycerol backbone. Lipase exists widely in nature, most prominently in plants, animals and microorganisms, among which microorganisms are the most important source of lipase. Microbial lipases have been adapted for numerous industrial applications due to their substrate specificity, heterogeneous patterns of expression and versatility (i.e., capacity to catalyze reactions at the extremes of pH and temperature as well as in the presence of metal ions and organic solvents). Now they have been introduced into applications involving the production and processing of food, pharmaceutics, paper making, detergents, biodiesel fuels, and so on. In this mini-review, we will focus on the most up-to-date research on microbial lipases and their commercial and industrial applications. We will also discuss and predict future applications of these important technologies.

Effects of Solvents on the Glycerolysis Performance of the SBA-15 Supported Lipases

In this study, Candida antarctica lipase B (CALB), Rhizomucor miehei lipase (RML) and Lecitase^® Ultra (LU) were immobilized onto the mesoporous silica SBA-15. The glycerolysis performance of the obtained supported lipases (lipase@SBA-15) in solvent systems was carefully investigated. LU@SBA-15 exhibited good glycerolysis performance in solvent-free system, with diacylglycerols (DAG) content and triacylglycerols (TAG) conversion at 52.4 and 98.6% respectively obtained after 12 h reaction at 60°C. CALB@SBA-15 showed good glycerolysis activity in tert-pentanol and tert-butanol systems, with TAG conversion over 90% obtained. In addition, the present CALB@SBA-15 exhibited selectivity for monoacylglycerols (MAG) production, with glycerol to TAG molar ratio increased to 3:1, MAG content over 80% and TAG conversion over 99% could be obtained from both tert-pentanol and tert-butanol systems. However, RML@SBA-15 showed low glycerolysis activity neither in solvent nor in solvent-free systems. The present results favor the practical enzymatic design for MAG and DAG production.

Preparing spray-dried cholesterol free salad dressing emulsified with enzymatically synthesized mixed mono- and diglycerides from rice bran oil and glycerol

A spray-dried cholesterol free salad dressing powder was developed using mixed mono- and diglycerides (MG-DG) as emulsifier. The optimum conditions for enzymatic synthesis of the MG-DG from rice bran oil (RBO) and glycerol (Gly) using Candida antarctica lipase was investigated. The synthesis was done by glycerolysis of refined RBO and Gly at molar ratios of 2:1, 2.5:1 and 3:1 (Gly to RBO) and enzyme concentrations of 2% and 5%. Highest MG and DG yield (0.54 ± 0.01 and 0.49.03 ± 0.0 mg/mL) was obtained in sample prepared using 2:1 molar ratio and 5% enzyme concentration and this sample is considered optimum. Salad dressings prepared using 0.5, 1.0, and 1.5% MG-DG concentration (of optimum MG-DG) were spray dried at inlet temperatures of 150, 160 and 170 °C to find the best conditions. Salad dressing of 0.5% MG-DG spray-dried at 170 °C had the highest powder yield (42.70%), solubility (98.04%) and stability (100%). After reconstitution, this optimum sample was compared well next to a control salad dressing prepared using commercial distilled monoglycerides. These findings demonstrate the feasibility of preparing a spray dried salad dressing powder with the synthesized MG-DG as an emulsifier.

Microbial lipase production: A deep insight into the recent advances of lipase production and purification techniques

Importance of enzymes is ever-rising particularly microbial lipases holding great industrial worth owing to their potential to catalyze a diverse array of chemical reactions in aqueous as well as nonaqueous settings. International lipase market is anticipated to cross USD 797.7 million till 2025, rising at a 6.2% compound annual growth rate from 2017 to 2025. The recent breakthrough in the field of lipase research is the generation of new and upgraded versions of lipases via molecular strategies. For example, integration of rational enzyme design and directed enzyme evolution to attain desired properties in lipases. Normally, purification of lipase with significant purity is achieved through a multistep procedure. Such multiple step approach of lipase purification entails both conventional and novel techniques. The present review attempts to provide an overview of different aspects of lipase production including fermentation techniques, factors affecting lipase production, and purification strategies, with the aim to assist researchers to pick a suitable technique for the production and purification of lipase.

Immobilized Lipase in the Synthesis of High Purity Medium Chain Diacylglycerols Using a Bubble Column Reactor: Characterization and Application

Novozym^® 435, an immobilized lipase from Candida antarctica B. (CALB), was used as a biocatalyst for the synthesis of high purity medium chain diacylglycerol (MCD) in a bubble column reactor. In this work, the properties of the MCD produced were characterized followed by determining its practical application as an emulsifier in water-in-oil (W/O) emulsion. Two types of MCDs, namely, dicaprylin (C₈-DAG) and dicaprin (C₁₀-DAG), were prepared through enzymatic esterification using the following conditions: 5% Novozym^® 435, 2.5% deionized water, 60°C for 30 min followed by purification. A single-step molecular distillation (MD) (100–140°C, 0.1 Pa, 300 rpm) was performed and comparison was made to that of a double-step purification with MD followed by silica gel column chromatography technique (MD + SGCC). Crude C₈-DAG and C₁₀-DAG with DAG concentration of 41 and 44%, respectively, were obtained via the immobilized enzyme catalyzing reaction. Post-purification via MD, the concentrations of C₈-DAG and C₁₀-DAG were increased to 80 and 83%, respectively. Both MCDs had purity of 99% after the MD + SGCC purification step. Although Novozym^® 435 is a non-specific lipase, higher ratios of 1,3-DAG to 1,2-DAG were acquired. Via MD, the ratios of 1,3-DAG to 1,2-DAG in C₈-DAG and C₁₀-DAG were 5.8:1 and 7.3:1, respectively. MCDs that were purified using MD + SGCC were found to contain 1,3-DAG to 1,2-DAG ratios of 8.8:1 and 9.8:1 in C₈-DAG and C₁₀-DAG, respectively. The crystallization and melting peaks were shifted to higher temperature regions as the purity of the MCD was increased. Dense needle-like crystals were observed in MCDs with high purities. Addition of 5% C₈-DAG and C₁₀-DAG as emulsifier together in the presence of 9% of hydrogenated soybean oil produced stable W/O emulsion with particle size of 18 and 10 μm, respectively.

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.

Evaluation of Sodium Stearoyl-2-Lactylate and 1, 3-Diacylglycerol Blend Supplementation in Diets with Different Energy Content on the Growth Performance, Meat Quality, Apparent Total Tract Digestibility, and Blood Lipid Profiles of Broiler Chickens

We evaluated the effects of supplementing an emulsifier blend (sodium stearoyl-2-lactylate and 1, 3-diacylglycerol) in diets with different energy content (normal and 100 kcal/kg reduced) on the growth performance, meat quality, apparent total tract digestibility (ATTD), and blood lipid profile of broiler chickens. Male broiler chickens (n = 1024), with an initial body weight (BW) of 43.60±0.2 g, were used in a 35-day trial. Broiler chickens of similar body weight were randomly allocated to one of four treatment groups in a 2 × 2 factorial arrangement with two levels of dietary energy content and with or without emulsifier blend. Broiler chickens fed on emulsifier blend supplemented diet had a higher body weight gain (BWG) during d 7-21, d 21-35, and overall period (P<0.05), higher BW during overall period (P<0.05), and lower feed conversion ratio (FCR) during d 7-21, d 21-35, and overall period (P<0.05) compared with broilers fed on diets without emulsifier supplementation. Broiler chickens fed on the diet with low energy content had a lower BWG during d 1-7, d 21-35, and overall period (P<0.05), lower BW during overall period, and higher FCR during d 1-7, d 21-35, and overall period (P<0.05). The ATTD of energy tended to decrease in response to low-energy content diet (P<0.10). Drip loss at 7 d post slaughter tended to decrease in response to dietary emulsifier blend supplementation (P<0.10). However, no interactive effects of dietary energy content and emulsifier blend supplementation (P>0.10) were observed on the growth performance, ATTD, blood lipid profiles, meat quality and relative organ weight. In conclusion, dietary emulsifier blend supplementation could improve growth performance, while low dietary energy content would decrease growth performance and ATTD of energy.

Production of trans-free interesterified fat using indigenously immobilized lipase

Enzymatic interesterification was carried out between high-oleic canola oil and fully hydrogenated soybean oil using indigenously immobilized Thermomyces lanuginosus lipas substrate concentration, moisture content of enzyme, and enzyme load. Interesterification resulted in a decrease in the concentration of tri-unsaturated and trisaturated TAG and an increase of mono- and di-saturated TAG as observed by reversed-phase HPLC. The alteration in TAG composition and the presence of new TAG species after interesterification was correlated with extended plasticity characterized by lower slip melting point with a significant change in functionality and consistency of the interesterified product. Thermal and structural properties of the blends before and after interesterification were assessed by differential scanning calorimetry (DSC), X-ray diffraction and polarized light microscopy. Trans-fat analysis indicated the absence of any trans fatty acid in the final interesterified product. The resultant interesterified products with varying slip melting points can be used in the formulation of healthier fat and oil products and address a critical industrial demand for trans free formulations for base-stocks of spreads, margarines, and confectionary fats.

Lipases: Sources, Production, Purification, and Applications

Background and Sources: Lipase enzyme is a naturally occurring enzyme found in the stomach and pancreatic juice. Its function is to digest fats and lipids, helping to maintain correct gallbladder function. Lipase is the one such widely used and versatile enzyme. These enzymes are obtained from animals, plants and as well as from several microorganisms and are sufficiently stable. These are considered as nature's catalysts, but commercially, only microbial lipases are being used significantly. Applications: They found enormous application in the industries of fat and oil processing, oleochemical industry, food industry, detergents, pulp and paper industry, detergents, environment management, tea processing, biosensors and cosmetics and perfumery. Various recent patents related to lipases have been revised in this review. Conclusion: Lipases are very peculiar as they have the ability to hydrolyse fats into fatty acids and glycerols at the water-lipid interface and can reverse the reaction in non-aqueous media. This natural ability makes it the most widely used enzyme in various industrial applications. This article deals with the immense versatility of lipase enzymes along with the recent advancements done in the various fields related to their purification and mass production in industries.

Immobilization of Candida antarctica Lipase B onto organically-modified SBA-15 for efficient production of soybean-based mono and diacylglycerols

In this study, SBA-15 was modified by a series of silane coupling reagents and later used to immobilize Candida antartica lipase B (CALB). The enzymatic properties of the immobilized CALB samples were studied. In addition, the catalytic performance in glycerolysis of soybean oil for diacylglycerols (DAG) production was also investigated. The highest enzymatic activity up to 6100.00 ± 246.41 U/g was observed from the propyl methacrylate group modified SBA-15 supported CALB. No loss of activity was observed from the propyl methacrylate group modified SBA-15 supported CALB, but a higher-than-initial activity was notably found from 3-aminopropyl group and n-octyl group modified SBA-15 supported CALB after a 4-h incubation in air at 70 °C. 1-isocyanatopropane group modified SBA-15 supported CALB exhibited selectivity for DAG production. DAG content up to 61.90 ± 2.38 wt% and a DAG/MAG ratio at 3.11 ± 0.08 was obtained after a 24-h reaction at 60 °C in a solvent-free system.

Metabolomics investigation of dietary effects on flesh quality in grass carp (Ctenopharyngodon idellus)

Background

The ultrahigh density intensive farming model of grass carp (Ctenopharyngodon idellus) may elicit growth inhibition, decrease flesh quality, and increase disease susceptibility of fish. The degradation in quality and excessive fat accumulation in cultured C. idellus have long been attributed to possible alterations in the lipid metabolism of fish muscle tissues as a result of overnutrition from artificial diets. To investigate the effects of different diets on fish muscle quality, a large-scale metabolomics study was performed on 250 tails of C. idellus.

Findings

The experimental fish were divided into four groups based on sex and diet—female artificial feed (FAF), female grass feed, male artificial feed (MAF), and male grass feed (MGF). After a 113-day rearing period, the artificial feed (AF) group showed a significantly higher total mass of muscle fat (P < 0.01), with the FAF group being the highest. Metabolomics profiling based on liquid chromatography-mass spectrometry revealed distinctive patterns of clustering according to the four groups. Overall, artificial feeding was associated with higher concentrations of docosapentaenoic acid, dihomo-gamma-linolenic acid, and arachidonic acid, whereas grass feeding was associated with elevated n-3 unsaturated fatty acids (UFAs) such as eicosapentaenoic acid, alpha-linolenic acid, and gamma-linolenic acid. Artificial feeding also resulted in significant increased docosahexaenoic acid in MAF muscle than in MGF fish, whereas there was no significance in the comparison of female samples. Metabolic pathway analyses using both targeted and untargeted approaches consistently revealed that arachidonic acid metabolism and steroid hormone biosynthesis pathways were significantly different between AF and grass fed groups.

Conclusions

Our results suggest that grass is a better source of dietary fatty acid and protein when compared to artificial feed. Grass feeding could effectively lower triglycerides in serum, reduce fat accumulation, and alter lipid compositions in fish muscle by increasing the concentrations of n-3 UFAs, leading to better nutrition and health.