Enzymatic enrichment of n-3 polyunsaturated fatty acid glycerides by selective hydrolysis

Preparation of medium- and long-chain triacylglycerols rich in n-3 polyunsaturated fatty acids by bio-imprinted lipase-catalyzed interesterification

Medium and long-chain triacylglycerol (MLCT) rich in n-3 polyunsaturated fatty acids (PUFAs) were obtained in three-hour interesterification of fish oil with medium-chain triacylglycerol (MCTs), using lipase bio-imprinted with surfactant as a catalyst. Initially, for bio-imprinted lipase preparation, the interesterification reaction conditions were optimized, resulting in a lipase with 1.47 times higher catalytic activity compared to control (non-bio-imprinted). Afterwards, the reaction conditions for MLCT synthesis were optimized, using bio-imprinted lipase as a catalyst. The reaction reached equilibrium within first three hours at 70 °C temperature, 4 wt% lipase load, and molar ratio of substrate 1:1.5. Under these conditions, final product contained 18.52% MCT, 56.65% MLCT, and 24.83% long-chain triacylglycerol (LCT). To reduce the MCT content, a solvent extraction process was performed, yielding 2.42% MCT, 56.19% MLCT, and 41.39% LCT. The obtained structured lipids (SLs), enriched in n-3 PUFAs, offer significant health benefits, enhanced bioavailability, with potential applications in functional foods and nutraceuticals.

Preparation of functional oils rich in phytosterol esters and diacylglycerols by enzymatic transesterification

Phytosterol esters (PEs) and diacylglycerols (DAGs) have various health benefits in humans. In this study, PEs and DAGs were synthesized by lipase-catalyzed transesterification between a natural oil and phytosterols. First, commercial lipases were screened for transesterification and were further verified using multiple-ligand molecular docking. AYS "Amano" (a lipase from Candida rugosa) was found to be the optimum lipase. Subsequently, the enzymatic transesterification conditions were optimized. The optimized conditions were determined to be a 1:2 M ratio of phytosterols to oil, 100 mmol/L phytosterols, and 9 % AYS "Amano", and 50 °C for 24 h in 20 mL n-hexane. Under these conditions, over 70 % of phytosterols were converted to PEs. In this study, an efficient enzymatic process was developed to produce value-added functional oils rich in PEs and DAGs, with PEs content ≥ 31.6 %, DAGs content ≥ 11.2 %, acid value ≤ 0.91 mg KOH/g, and peroxide value ≤ 2.38 mmol/kg.

Marine-Derived Lipases for Enhancing Enrichment of Very-Long-Chain Polyunsaturated Fatty Acids with Reference to Omega-3 Fatty Acids

Omega-3 fatty acids are essential fatty acids that are not synthesised by the human body and have been linked with the prevention of chronic illnesses such as cardiovascular and neurodegenerative diseases. However, the current dietary habits of the majority of the population include lower omega-3 content compared to omega-6, which does not promote good health. To overcome this, pharmaceutical and nutraceutical companies aim to produce omega-3-fortified foods. For this purpose, various approaches have been employed to obtain omega-3 concentrates from sources such as fish and algal oil with higher amounts of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). Among these techniques, enzymatic enrichment using lipase enzymes has gained tremendous interest as it is low in capital cost and simple in operation. Microorganism-derived lipases are preferred as they are easily produced due to their higher growth rate, and they hold the ability to be manipulated using genetic modification. This review aims to highlight the recent studies that have been carried out using marine lipases for the enrichment of omega-3, to provide insight into future directions. Overall, the covalent bond-based lipase immobilization to various support materials appears most promising; however, greener and less expensive options need to be strengthened.

Concentration of docosahexaenoic acid from tuna oil via a two lipase-catalyzed reaction

Docosahexaenoic acid (DHA) was concentrated successfully in the glyceride fractions from tuna oil via a two-step enzyme reaction involving hydrolysis and ethanolysis. In the first step, Candida rugosa lipase-catalyzed hydrolysis was carried out to concentrate DHA in the glyceride fractions. The DHA content in the glyceride fraction after hydrolysis increased from 30% in the initial tuna oil to 46%. In the second step, Lipozyme RM IM-catalyzed ethanolysis was conducted with the reaction mixture from the first step to further concentrate DHA in the glyceride fraction. In this step, the reaction mixture obtained from the first step was employed directly in Lipozyme RM IM-catalyzed ethanolysis without additional steps needed to remove free fatty acid. Finally, DHA was concentrated from an initial content of 30% in the tuna oil to 68.4% in the glyceride fractions via a novel two-step enzyme reaction strategy.

Characterization of a New Thermostable and Organic Solution-Tolerant Lipase from Pseudomonas fluorescens and Its Application in the Enrichment of Polyunsaturated Fatty Acids

The search for and characterization of new lipases with excellent properties has always been urgent and is of great importance to meet industrial needs. In this study, a new lipase, lipB, from Pseudomonas fluorescens SBW25, belonging to the lipase subfamily I.3, was cloned and expressed in Bacillus subtilis WB800N. Enzymatic properties studies of recombinant LipB found that it exhibited the highest activity towards p-nitrophenyl caprylate at 40 °C and pH 8.0, retaining 73% of its original activity after incubation at 70 °C for 6 h. In addition, Ca²⁺, Mg²⁺, and Ba²⁺ strongly enhanced the activity of LipB, while Cu²⁺, Zn²⁺, Mn²⁺, and CTAB showed an inhibiting effect. The LipB also displayed noticeable tolerance to organic solvents, especially acetonitrile, isopropanol, acetone, and DMSO. Moreover, LipB was applied to the enrichment of polyunsaturated fatty acids from fish oil. After hydrolyzing for 24 h, it could increase the contents of polyunsaturated fatty acids from 43.16% to 72.18%, consisting of 5.75% eicosapentaenoic acid, 19.57% docosapentaenoic acid, and 46.86% docosahexaenoic acid, respectively. The properties of LipB render it great potential in industrial applications, especially in health food production.

Comparative Lipidomics Profiling of Acylglycerol from Tuna Oil Selectively Hydrolyzed by Thermomyces Lanuginosus Lipase and Candida Antarctica Lipase A

Lipase hydrolysis is an effective method to develop different functional types of lipids. In this study, tuna oil was partially hydrolyzed at 30% and 60% by Thermomyces lanuginosus lipase (TL 100 L) and Candida Antarctica lipase A (ADL), respectively, to obtain lipid-modified acylglycerols. The lipidomic profiling of the acylglycerols was investigated by UPLC-Q-TOF-MS and GC-MS to clarify the lipid modification effect of these two lipases on tuna oil. The results showed that 247 kinds of acylglycerols and 23 kinds of fatty acids were identified in the five samples. In the ADL group, the content of triacylglycerols (TAG) and diacylglycerols (DAG) increased by 4.93% and 114.38%, respectively, with an increase in the hydrolysis degree (HD), while there was a decreasing trend in the TL 100 L group. TL 100 L had a better enrichment effect on DHA, while ADL was more inclined to enrich EPA and hydrolyze saturated fatty acids. Cluster analysis showed that the lipids obtained by the hydrolysis of TL 100 L and ADL were significantly different in the cluster analysis of TAG, DAG, and monoacylglycerols (MAG). TL 100 L has strong TAG selectivity and a strong ability to hydrolyze acylglycerols, while ADL has the potential to synthesize functional lipids containing omega-3 PUFAs, especially DAG.

Functional and emulsification characteristics of phospholipids and derived o/w emulsions from peony seed meal

Peony seed phospholipids (PPLs), a kind of multifunctional plant-like phospholipids were extracted from peony seed meal. We investigated the functional properties of PPLs and compared their emulsification performance in corn oil-peony seed oil o/w emulsion systems with that of soy lecithin (DPLs). The PPLs were characterized with the higher content of phosphatidylcholine (PC) (416 ± 28 mg/g) and lyso-phosphatidylcholine (LPC) (43 ± 14 mg/g) fractions, and lower content of phosphatidylethanolamine (PE) (71 ± 13 mg/g). The polyunsaturated fatty acids showed higher content (83.25%), with the highest content of linoleic acid (46.05%) in PPLs. PPLs-emulsions showed smaller average particle size and higher loaded peony seed oil content at pH 5, temperature 50 °C, and about 60% corn oil content. PPLs-emulsions imparted better hydroxyl radical scavenging efficiency and reducing power than DPLs. Our results suggest that PPLs can be used as emulsifiers with improved antioxidant properties.

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.

The High ‘Lipolytic Jump’ of Immobilized Amano A Lipase from Aspergillus niger in Developed ‘ESS Catalytic Triangles’ Containing Natural Origin Substrates

Lipase Amano A from Aspergillus niger (AA-ANL) is among the most commonly applied enzymes in biocatalysis processes, making it a significant scientific subject in the pharmaceutical and medical disciplines. In this study, we investigated the lipolytic activity of AA-ANL immobilized onto polyacrylic support IB-150A in 23 oils of natural origin containing various amounts of polyunsaturated fatty acids (PUFAs) and monounsaturated fatty acids (MUFAs). The created systems were expressed as an ‘ESS catalytic triangle’. A distinct ‘jump’ (up to 2400%) of lipolytic activity of immobilized AA-ANL compared to free lipase and hyperactivation in mostly tested substrates was observed. There was a ‘cutoff limit’ in a quantitative mutual ratio of ω-PUFAs/MUFAs, for which there was an increase or decrease in the activity of the immobilized AA-ANL. In addition, we observed the beneficial effect of immobilization using three polyacrylic supports (IB-150A, IB-D152, and IB-EC1) characterized by different intramolecular interactions. The developed substrate systems demonstrated considerable hyperactivation of immobilized AA-ANL. Moreover, a ‘lipolytic jump’ in the full range of tested temperature and pH was also observed. The considerable activity of AA-ANL-IB-150A after four reuse cycles was demonstrated. On the other hand, we observed an essential decrease in stability of immobilized lipase after 168 h of storage in a climate chamber. The tested kinetic profile of immobilized AA-ANL confirmed the increased affinity to the substrate relative to lipase in the free form.