Enzymatic Production of ABA-Type Structured Lipids Containing Omega-3 and Medium-Chain Fatty Acids: Effects of Different Acyl Donors on the Acyl Migration Rate

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.

Progress and perspectives of enzymatic preparation of human milk fat substitutes

Human milk fat substitutes (HMFS) with triacylglycerol profiles highly similar to those of human milk fat (HMF) play a crucial role in ensuring the supply in infant nutrition. The synthesis of HMFS as the source of lipids in infant formula has been drawing increasing interest in recent years, since the rate of breastfeeding is getting lower. Due to the mild reaction conditions and the exceptionally high selectivity of enzymes, lipase-mediated HMFS preparation is preferred over chemical catalysis especially for the production of lipids with desired nutritional and functional properties. In this article, recent researches regarding enzymatic production of HMFS are reviewed and specific attention is paid to different enzymatic synthetic route, such as one-step strategy, two-step catalysis and multi-step processes. The key factors influencing enzymatic preparation of HMFS including the specificities of lipase, acyl migration as well as solvent and water activity are presented. This review also highlights the challenges and opportunities for further development of HMFS through enzyme-mediated acylation reactions.

Advances in enzyme biocatalysis for the preparation of functional lipids

Functional lipids, mainly ω-3 polyunsaturated fatty acids (n-3 PUFAs) such as eicosapentaenoic (EPA; 20:5n-3) and docosahexaenoic (DHA; 22:6n-3), are known to have a variety of health benefits. Lipases and phospholipases are widely used to prepare different forms of structured lipids, since biocatalytic methods can be carried out under mild conditions, preserving the quality of the products. On the other hand, many processes still are conducted at high temperatures and with organic solvents, which are conditions unfavorable for the production of nutritional products. This article gives an updated overview of enzyme biocatalysis methods for the preparation of different derivatives containing n-3 PUFAs, including specific reactions, enzyme immobilization research for high-efficiency catalysis, and enzyme engineering technologies (higher selectivity, stability, and activity). Furthermore, advanced control strategies of biocatalytic processes and reactors are presented. The future prospect and opportunities for marine functional lipids are also discussed. Therefore, the obtainment of enzymes endowed with superior properties and the development of optimized processes, still have to be pursued to achieve greener bio-catalyzed processes.

A novel sn-1,3 specific lipase from Janibacter sp. as catalysts for the high-yield synthesis of long-medium-long type structured triacylglycerols

Our study offers a novel sn-1,3 specific lipase MAJ1 from marine member Janibacter sp. strain HTCC2649 for preparing long-medium-long (LML) type structured triacylglycerols (TAGs). Firstly, the resin ECR1030 was selected as a suitable support for the immobilization of lipase MAJ1. An efficient synthesis of LML-type structured TAGs by the immobilized lipase MAJ1-catalyzed interesterification of methyl palmitate and tricaprylin was studied in a solvent-free system. The reaction conditions, including substrate molar ratio, temperature and enzyme loading, were optimized. Under the optimum conditions (immobilized lipase MAJ1 of 45 U/g, substrate molar ratio of 4:1, temperature of 35 °C, reaction time of 24 h), the structured TAGs with double long chains (DLCST) were obtained in a yield of 44.3 mol%. Secondly, multi-dimensional mass spectrometry-based shotgun lipidomics (MDMS-SL) was employed to quantify each TAG positional isomer in DLCST. The content of 1,3-dipalmitoyl-2-capryloyl-sn-glycerol in DLCST was 97.6% determined by the MDMS-SL technology.

Enzymatic modification to produce health-promoting lipids from fish oil, algae and other new omega-3 sources: A review

Lipases are a versatile class of enzymes that have aroused great interest in the food and pharmaceutical industries due to their ability to modify and synthesize new lipids for functional foods. Omega-3 polyunsaturated fatty acids (omega-3 PUFAs), such as eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), have shown important biological functions promoting human health, especially in the development and maintenance of brain function and vision. Lipases allow selective production of functional lipids enriched in omega-3 PUFAs and are unique enzymatic tools to improve the natural composition of lipids and provide specific bioactivities. This review comprises recent research trends on the enzymatic production of bioactive, structured lipids with improved nutritional characteristics, using new enzymatic processing technologies in combination with novel raw materials, including microalgal lipids and new seed oils high in omega-3 fatty acids. An extensive number of lipase applications in the synthesis of health-promoting lipids enriched in omega-3 fatty acids by enzymatic modification is reviewed, considering the main advances in recent years for production of ethyl esters, 2-monoacylglycerols and structured triglycerides and phospholipids with omega-3 fatty acids, in order to achieve bioactive lipids as new foods and drugs.

Ultrasonic Pretreatment in Synthesis of Caprylic-Rich Structured Lipids by Lipase-Catalyzed Acidolysis of Corn Oil in Organic System and Its Physicochemical Properties

The current work was to evaluate the lipase-catalyzed acidolysis of corn oil with caprylic acid (CA) in organic system under bath ultrasonic pretreatment and to analyze the physicochemical properties of structured lipids (SLs). Under optimum conditions (Novozym 40086 lipase, 200 W ultrasound power, 10 min ultrasound pretreatment time, 12% dosage of lipase, Triacylglycerol (TAG)/Free fatty acids (FFA): 1/8, 40 °C for 6 h), a 45.55% CA incorporation was obtained (named SLs-U). The highest CA incorporation was 32.75% for conventional method at reaction time of 10 h (named SLs-N). The predominant TAG types of SLs were MLM (medium-, long- and medium-chain-type TAGs) and MLL (medium-, long- and long-chain-type TAGs). X-ray diffraction analysis revealed that both SLs-U and SLs-N present β form. Differential scanning calorimetry (DSC) analysis showed that both SLs-U and SLs-N show a lower melting and crystallization temperature than corn oil. This study suggested that bath ultrasonic pretreatment can accelerate lipase-catalyzed acidolysis synthesis of MLM structured lipids in an organic system, and two kinds of structured lipids show similar physicochemical properties.

Recent Research Trends on the Enzymatic Synthesis of Structured Lipids

Structured lipids (SLs) are lipids that have been chemically or enzymatically modified from their natural biosynthetic form. Because SLs are made to possess desired nutritional, physicochemical, or textural properties for various applications in the food industry, many research activities have been aimed at their commercialization. The production of SLs by enzymatic procedures has a great potential in the future market because of the specificity of lipases and phospholipases used as the biocatalysts. The aim of this review is to provide concise information on the recent research trends on the enzymatic synthesis of SLs of commercial interest, such as medium- and long-chain triacylglycerols, human milk fat substitutes, cocoa butter equivalents, trans-free or low-trans plastic fats (such as margarines and shortenings), low-calorie fats/oils, health-beneficial fatty acid-rich fats/oils, mono- or diacylglycerols, and structurally modified phospholipids. This limited review covers 108 research articles published between 2010 and 2014 which were searched in Web of Science.