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

The impact of formulation design on the oral bioavailability of omega-3 polyunsaturated fatty acids

Omega-3 polyunsaturated fatty acids (n-3 PUFA) are essential dietary supplements with widespread health benefits. However, achieving therapeutic n-3 PUFA levels in systemic circulation represents a significant dosing challenge, complicated by a complex interaction between different physiological and chemical factors. Recently, significant efforts have been directed towards creating "bio-accessible" n-3 PUFA formulations that overcome this dosing challenge by enabling increased oral absorption across the small intestine. However, the impact of varying physiochemical formulation properties on n-3 PUFA bioavailability remains poorly understood and requires further investigation. This review explores the impact of formulation design, including self-emulsifying systems, micro- and nano-emulsions, chewable gels, and microencapsulation, on n-3 PUFA pharmacokinetics, considering both clinical and preclinical investigations. Key challenges in developing highly bioavailable n-3 PUFA formulations and quantifying their absorption, biodistribution and metabolism are discussed. Finally, recent progress in developing next-generation n-3 PUFA formulations, including solid lipid nanoparticles and nanostructured lipid carriers, and their targeting through innovative lipid structuring approaches will be addressed. The oral bioavailability of n-3 PUFA is ultimately influenced by multiple design factors related to each formulation strategy, underscoring the need for a systematic formulation approach that involves comprehensive testing of candidate formulation under simulated gastrointestinal conditions.

Selective production of functional sn-1,3-diacylglycerol by microbial lipases: A comprehensive review

Since early 1990s, diacylglycerol (DAG) has drawn a continuous trending interest among researchers and oil industries/markets as part of a reduced-energy diet due to its functions to prevent and manage obesity. With the accumulated knowledge, a stereoisomer of sn-1,3-DAG is regarded as the sole compound to contribute to DAG's functions. sn-1,3-DAG can be produced by direct esterification of free fatty acids and glycerol, partial hydrolysis of TAGs/edible oils, and glycerolysis of TAGs/edible oils with glycerol using the regioselective microbial lipases as the catalyst. However, the specific microbial lipases with high efficiency to produce sn-1,3-DAG and their catalytic mechanisms are still a mystery. Herein, we provide an overview of metabolic fates of three stereoisomers of DAGs including sn-1,3-DAG, sn-1,2-DAG and/or sn-2,3-DAG, and synthesis process for sn-1,3-DAG, and critically outline the microbial lipases to selectively produce sn-1,3-DAG, and their pathways and mechanisms, which hopefully presents a reasonable full picture of functions, synthesis schemes, and catalytic performance to improve regioselectivity and catalytic efficiency for sn-1,3-DAG production with high yield.

Redefining shortening: Systematically characterizing traditional and new enriched diacylglycerol shortening and exploring their impact on processing applications

Compared to lard-based shortenings, diacylglycerol (DAG)-based shortenings have demonstrated beneficial effects, such as lowering blood lipids, and reducing postprandial blood glucose levels. In this study, different chain-length DAG oils were blended with lower melting point peanut oil DAG oil (PO-DAG-oil). The blend ratios for the three types of DAG-based shortenings were determined based on the solid fat content (SFC) of lard. Subsequently, 1 % of various emulsifiers were added, and the crystallization properties, rheological and textural characteristics, polymorphism, microstructure, water-absorbing capacity, and plasticity of the four shortening systems were examined. The emulsifiers found to be suitable for lard shortening, long chain fatty acid DAG (LCD-shortening), medium chain fatty acid DAG (MCD-shortening), and medium and long chain fatty acid DAG (MLCD-shortening) were Span60, PGFE, PGFE, and MAG, respectively. Cakes baked using DAG-based shortenings exhibited superior textural properties compared to those made with lard-based shortenings, supporting the application of high-melting-point DAG oils in shortening formulations.

Synthesis of Enantiostructured Triacylglycerol Prodrugs Constituting an Active Drug Located at Terminal sn-1 and sn-3 Positions of the Glycerol Backbone

The current paper reports the asymmetric synthesis of a focused library of enantiostructured triacylglycerols (TAGs) constituting a potent drug of the NSAID type (ibuprofen or naproxen) along with a pure bioactive n-3 polyunsaturated fatty acid (PUFA) intended as a novel type of prodrug. In this second category, a TAG prodrug of the terminal sn-1 or sn-3 position of the glycerol skeleton is acylated with a single saturated medium-chain fatty acid (C6, C8, C10, or C12), and another with the drug entity; the PUFA (EPA or DHA) is located in the sn-2 position. This was accomplished by a six-step chemoenzymatic approach, two of which were promoted by a lipase, starting from enantiopure (R)- and (S)-solketals. The highly regioselective immobilized Candida antarctica lipase (CAL-B) played a crucial role in the regiocontrol of the synthesis. The most challenging key step involved the incorporation of the drugs that were activated as oxime esters by the lipase exclusively in the terminal position of glycerol that is protected as a benzyl ether. All combinations, a total of 32 such prodrug TAGs, were prepared, isolated, and fully characterized, along with 24 acylglycerol intermediates, obtained in very-high-to-excellent yields in the majority of cases.

A review on preparation and application of low-calorie structured lipids in food system

Low-calorie structured lipids are an advanced form of functional lipids made by changing the position of fatty acids attached to the glycerol backbone. The main reason for their production is to get nutraceutical lipids. Different methods are used to synthesize low-calorie structured lipids, like chemical or enzymatic methods. Initially, these lipids are prepared by using chemical methods. Synthesis of low-calorie structured lipids using enzymes is now in demand due to several advantages like good catalytic efficiency, environmentally friendly, and moderate reaction conditions. Enzymatic interesterification is mostly used in industries to make modified lipids like low-calorie structured lipids, human milk substitutes, cocoa butter equivalents, margarine, and shortenings. This review summarizes the synthesis, uses and clinical applications of modified lipids in food systems.

Supplementary Information

The online version contains supplementary material available at 10.1007/s10068-024-01689-8.

Effect of structured lipids as dietary supplements on the fatty acid profile, carcass yield, blood chemistry, and abdominal fat deposition of female broilers

An experiment was conducted to evalute the effects of adding palm olein (POL), modified palm olein (high degree of acyl migration palm olein, H-AMD), and lard (total fatty acid saturation degree is similar to palm olein) to the diet of broilers. The study assessed production performance, fatty acid absorption, and abdominal fat deposition. A total of 100 one-week-old female broiler chicks were randomly assigned to three-tiered pens and fed five experimental diets. Enzymatic interesterification of POL causes acyl migration, transforming 1-palmitoyl-2,3-dioleoyl-sn-glycerol (sn-POO) and 1,3-dipalmitoyl-2-oleoyl-sn-glycerol (sn-POP) into 1,3-dioleoyl-2-palmitoyl-sn-glycerol (sn-OPO) and 1,2-dipalmitoyl-3-oleoyl-sn-glycerol (sn-PPO), which increases the saturated fatty acid content at the sn-2 position. Feeding broilers with this modified oil has improved the absorption effect of saturated fatty acids and increased the content of palmitic acid in abdominal tissue by 1.55%-1.69%. The impact on the content and positional distribution of fatty acids deposited in the body is limited. Low-density lipoprotein cholesterol (LDL-C) levels decreased by 34%, while high-density lipoprotein cholesterol (HDL-C) levels increased by 23%, resulting in a lower risk of atherosclerosis. No significant differences have been observed in carcass yield results of the POL and H-AMD groups. Compared with animal-derived oils such as lard which are also rich in saturated fatty acids at the sn-2 position, plant-derived oils such as POL and its modified products have a smaller effect on abdominal fat deposition.

Preparation of Chitosan Oleogel from Capillary Suspension and Its Application in Pork Meatballs

In the oil dispersion of chitosan, the formation of a capillary bridge was triggered by adding a small amount of water to obtain an oleogel. With this method, the types of liquid oil and the ratio of oil/chitosan/water were explored to achieve an optimal oleogel. MCT performed best, followed by soybean oil, which was chosen for its edibility and cost. Increasing chitosan from 15% to 45% reduced oil loss from 46% to 13%, and raising the water/chitosan ratio from 0 to 0.8 lowered oil loss from 37% to 13%. After normalization, the optimal soybean oil, chitosan, and water ratio was 1:0.45:0.36, yielding a solid-like appearance, minimal oil loss of 13%, and maximum gel strength and viscosity. To assess the potential application of the optimized oleogel, it was incorporated into pork meatballs as a replacement for pork fat. Textural and cooking experiments revealed that as the oleogel content increased, the hardness of the pork meatballs increased, while the cooking loss decreased. It suggested that the chitosan oleogel could enhance the quality of pork meatballs while also contributing to a healthier product by reducing saturated fat content.

Synthesis of Enantiostructured Triacylglycerols Possessing a Saturated Fatty Acid, a Polyunsaturated Fatty Acid and an Active Drug Intended as Novel Prodrugs

This report describes the asymmetric synthesis of a focused library of enantiopure structured triacylglycerols (TAGs) comprised of a single saturated fatty acid (C6, C8, C10, C12, C14 or C16), a pure bioactive n-3 polyunsaturated fatty acid (EPA or DHA) and a potent drug (ibuprofen or naproxen) intended as a novel type of prodrug. One of the terminal sn-1 or sn-3 positions of the glycerol backbone is occupied with a saturated fatty, the remaining one with a PUFA, and the drug entity is present in the sn-2 position. This was accomplished by a six-step chemoenzymatic approach starting from enantiopure (R)- and (S)-solketals. The highly regioselective immobilized Candida antarctica lipase (CAL-B) played a crucial role in the regiocontrol of the synthesis. All combinations, a total of 48 such prodrug TAGs, were prepared, isolated and fully characterized, along with 60 acylglycerol intermediates, obtained in very high to excellent yields.

An sn-2 regioselective lipase with cis-fatty acid preference from Cordyceps militaris: Biochemical characterization and insights into its regioselective mechanism

Lipase with unique regioselectivity is an attractive biocatalyst for elaborate lipid modification. However, the excavation of novel sn-2 regioselective lipases is difficult due to their scarcity in nature, with Candida antarctica lipase A (CALA) being the pronouncedly reported one. Here, we identified a novel CALA-like lipase from Cordyceps militaris (CACML7) via in silico mining. Through chiral-phase high-performance liquid chromatography, we determined that CACML7 displays sn-2 regioselectivity (>68 %) as does CALA, but exhibits distinctive chain length selectivity and bias against unsaturated fats. Notably, the curvature of the acyl-binding tunnel was expected to contribute to the 2.2-fold higher preference for cis-fatty acid (C18:1, cis-Δ9) over trans-fatty acid (C18:1, trans-Δ9) unlike trans-active CALA. Random pose docking of trioleoylglycerol (TOG) into the active site of a lid-truncated mutant of CACML7 revealed that TOG accepts a tuning fork conformation, of which the precise positioning of the reactive ester group towards the catalytic center was only favorable via sn-2 binding mode. The unique active site morphology, which we refer to as an "acyl-binding tunnel with a narrow entrance," may contribute to the sn-2 regioselectivity of CACML7. Our data provide an attractive model to better understand the mechanism underlying sn-2 regioselectivity.

Wild Mushrooms as a Source of Bioactive Compounds and Their Antioxidant Properties-Preliminary Studies

The aim of this study was to preliminarily determine the content of bioactive components in the fruiting bodies of four previously unstudied mushroom species: Aleuria aurantia, Phallus hadriani, Phanus conchatus, Geastrum pectinatum, their antioxidant activity and the content of polyphenols, minerals and heavy metals.

METHODS

Determination of active compounds by gas chromatography-mass spectrometry was carried out in addition to thermogravimetric determinations, quantitative determination of total polyphenols by spectrophotometry using Folin-Ciocalteu reagent, determination of antioxidant activity using 2,2-diphenyl-1-picryl hydrazyl radical (DPPH) and 2,2'-azino-di-[3-ethylbentiazoline sulphonated] (ATBS). In addition, spectrometric analysis of selected minerals and heavy metals was performed by inductively coupled plasma optical emission spectroscopy (ICP-OES).

RESULTS

The mushrooms analysed varied in terms of their bioactive constituents. They contained components with varying effects on human health, including fatty acids, oleamide, 1,2-dipalmitoylglycerol, (2-phenyl-1,3-dioxolan-4-yl)-methyl ester of oleic acid, deoxyspergualin, 2-methylenocholestan-3-ol, hexadecanoamide, isoallochan, 2,6-diaminopurine, and adenine. All contained polyphenols and varying amounts of minerals (calcium, magnesium, iron, zinc, potassium, phosphorus, sodium, copper, silicon and manganese) and exhibited antioxidant properties of varying potency. No exceedances of the permissible concentration of lead and cadmium were observed in any of them.

CONCLUSIONS

All of the mushrooms studied can provide material for the extraction of various bioactive compounds with physiological effects. In addition, the presence of polyphenols and minerals, as well as antioxidant properties and the absence of exceeding the permissible concentration of heavy metals, indicate that these species could be interesting material in the design of foods with health-promoting properties, nutraceuticals or dietary supplements. However, the use of the fruiting bodies of these mushrooms requires mandatory toxicological and clinical studies.

Medium- and Long-Chain Triacylglycerol: Preparation, Health Benefits, and Food Utilization

Medium- and long-chain triacylglycerol (MLCT) is a structured lipid with both medium- and long-chain fatty acids in one triacylglycerol molecule. Compared with long-chain triacylglycerol (LCT), which is mainly present in common edible oils, and the physical blend of medium-chain triacylglycerol with LCT (MCT/LCT), MLCT has different physicochemical properties, metabolic characteristics, and nutritional values. In this article, the recent advances in the use of MLCT in food formulations are reviewed. The natural sources and preparation of MLCT are discussed. A comprehensive summary of MLCT digestion, absorption, transport, and oxidation is provided as well as its health benefits, including reducing the risk of overweight, hypolipidemic and hypoglycemic effects, etc. The potential MLCT uses in food formulations, such as infant formulas, healthy foods for weight loss, and sports foods, are summarized. Finally, the current safety assessment and regulatory status of MLCT in food formulations are reviewed.

Enzymatic production process of capric acid-rich structured lipids: Development of formulation as a new therapeutic approach

The present work reports an optimization of the synthesis of MLM-type (medium, long, medium) structured lipids (SL) through an acidolysis reaction of grape seed oil with capric acid catalyzed by Rhizopus oryzae lipase immobilized. At first, tests were carried out by preparing the biocatalysts using enzyme loadings (0.15 to 1 g of enzymatic powder) for each gram of support. Enzyme loading was used 0.3 g of enzymatic powder, and hydrolytic activity of 1860 ± 23.4 IU/g was reached. Optimized conditions determined by the Central Composite Rotatable Design (CCRD) revealed that the acidolysis reaction reached approximately 59 % incorporation degree (%ID) after 24 h, in addition to the fact that the biocatalyst could maintain the incorporation degree in five consecutive cycles. From this high incorporation degree, cell viability assays were performed with murine fibroblast cell lines and human cervical adenocarcinoma cell lines. Concerning the cytotoxicity assays, the concentration of MLM-SL to 1.75 and 2 % v/v were able to induce cell death in 56 % and 64 % of adenocarcinoma cells, respectively. Human cervical adenocarcinoma cells showed greater sensitivity to the induction of cell death when using emulsions with MLM-SL > 1.75 % v/v compared to emulsions with lower content indicating a potential for combating carcinogenic cells.

Isolation of Fatty Acids from the Enzymatic Hydrolysis of Capsaicinoids and Their Use in Enzymatic Acidolysis of Coconut Oil

Herein we report the optimization of enzymatic hydrolysis of a mixture of capsaicinoids, capsaicin and dihydrocapsaicin obtained from chili peppers, and the utilization of the isolated fatty acids for the modification of coconut oil using enzyme catalyzed acidolysis. This work was carried out as the fatty acids that can be isolated from capsaicinoid hydrolysis have been shown to possess interesting biological properties. These biological properties could be better exploited by incorporating the fatty acids into a suitable delivery vehicle. The enzymatic hydrolysis of the mixture of capsaicin and dihydrocapsaicin was carried out using Novozym® 435 in phosphate buffer (pH 7.0) at 50℃. The enzyme catalyst could be reused in multiple cycles of the hydrolysis reaction. The desired 8-methyl-6-trans-nonenoic acid and 8-methylnonanoic acid were isolated from the hydrolysis reaction mixture using a simple extraction procedure with a 47.8% yield. This was carried out by first extracting the reaction mixture at pH 10 with ethyl acetate to remove any dissolved capsaicinoids and vanillyl amine side product. The fatty acids were isolated after adjustment of the pH of the reaction mixture to 5 and second extraction with ethyl acetate. The acidolysis of coconut oil with the obtained fatty acids was performed using Lipozyme® TL IM. The performance of the acidolysis reaction was evaluated using 1H-NMR spectroscopy and verified in selected cases using gas chromatography. The best performing conditions involved carrying out the acidolysis reaction at 60℃ with a 1.2 w/w ratio of the fatty acids to coconut oil and 10% enzyme loading for 72 h. This resulted in the incorporation of 26.61% and 9.86% of 8-methyl-6-trans-nonenoic acid and 8-methylnonanoic acid, respectively, into the modified coconut oil product. This product can act as a potential delivery vehicle for these interesting compounds.

Trends in Fat Modifications Enabling Alternative Partially Hydrogenated Fat Products Proposed for Advanced Application

The natural properties of oils and fats do not always allow for their direct use in industry (e.g., for food, cosmetics, and pharmaceuticals). Furthermore, such raw materials are often too expensive. Nowadays, the requirements for the quality and safety of fat products are increasing. For this reason, oils and fats are subjected to various modifications that make it possible to obtain a product with the desired characteristics and good quality that meets the needs of product buyers and technologists. The modification techniques of oils and fats change their physical (e.g., raise the melting point) and chemical properties (e.g., fatty acid composition). Conventional fat modification methods (hydrogenation, fractionation, and chemical interesterification) do not always meet the expectations of consumers, nutritionists, and technologists. In particular, Hydrogenation, while it allows us to obtain delicious products from the point of view of technology, is criticised for nutritional reasons. During the partial hydrogenation process, trans-isomers (TFA), dangerous for health, are formed. One of the modifications that meets current environmental requirements and trends in product safety and sustainable production is the enzymatic interesterification of fats. The unquestionable advantages of this process are the wide spectrum of possibilities for designing the product and its functional properties. After the interesterification process, the biologically active fatty acids in the fatty raw materials remain intact. However, this method is associated with high production costs. Oleogelation is a novel method of structuring liquid oils with small oil-gelling substances (even 1%). Based on the type of oleogelator, the methods of preparation can differ. Most oleogels of low molecular weight (waxes, monoglycerides, and sterols) and ethyl cellulose are prepared by dispersion in heated oil, while oleogels of high molecular weight require dehydration of the emulsion system or solvent exchange. This technique does not change the chemical composition of the oils, which allows them to keep their nutritional value. The properties of oleogels can be designed according to technological needs. Therefore, oleogelation is a future-proof solution that can reduce the consumption of TFA and saturated fatty acids while enriching the diet with unsaturated fatty acids. Oleogels can be named "fats of the future" as a new and healthy alternative for partially hydrogenated fats in foods.

Incrementing MCT Character of Coconut Oil Using Enzyme Catalyzed Interesterification

The fatty acid composition of coconut oil was modified using enzyme catalyzed interesterification with the aim of obtaining a product more alike to commercial MCT oils. This modification was carried out with the aim to obtain a product with some of the health benefits shown by MCT oils. Initially, lipase B from Candida antarctica immobilized on acrylic resin and lipozyme TL IM were tested as enzyme catalysts for the reaction. The enzyme catalysts have shown similar performance and lipozyme TL IM has been chosen as the catalyst based on its lower cost. The effects of reaction time, oil to methyl octanoate ratio, and enzyme loading on the reaction performance have been investigated with response surface methodology (RSM) utilizing the Box-Behnken approach. The optimized reaction was scaled up to 20 g. The possibility to source the medium chain fatty acid esters from coconut oil fatty acid distillate using a simple procedure was demonstrated and the possibility to use these esters for the interesterification of coconut oil has been demonstrated as well.