Synthesis of 1,3-dioleoyl-2-arachidonoylglycerol-rich structured lipids by lipase-catalyzed acidolysis of microbial oil from Mortierella alpina

Microbial oils (MOs) have gained widespread attention due to their functional lipids and health promoting properties. In this study, 1,3-dioleoyl-2-arachidonoylglycerol-rich structured lipids (SLs) were produced from MO and oleic acid (OA) via solvent-free acidolysis catalyzed by Lipozyme RM IM. Under the optimal conditions, the content of unsaturated fatty acids (UFAs) increased from 60.63 to 84.00%, while the saturated fatty acids (SFAs) content decreased from 39.37 to 16.00% at sn-1,3 positions in SLs. Compared with MO, arachidonic acid (ARA) content at the sn-2 position of SLs accounted for 49.71%, whereas OA was predominantly located at sn-1,3 positions (47.05%). Meanwhile, the most abundant triacylglycerol (TAG) species in SLs were (18:1-20:4-18:1), (20:4-20:4-18:1), (18:1-18:2-18:1), (18:1-18:2-18:0) and (24:0-20:4-18:1) with a relative content of 18.79%, 11.94%, 6.07%, 5.75% and 4.84%, respectively. Such novel SLs with improved functional properties enriched with UFAs are highly desirable and have the potential to be used in infant formula.

Selective synthesis of human milk fat-style structured triglycerides from microalgal oil in a microfluidic reactor packed with immobilized lipase

Human milk fat-style structured triacylglycerols were produced from microalgal oil in a continuous microfluidic reactor packed with immobilized lipase for the first time. A remarkably high conversion efficiency was demonstrated in the microreactor with reaction time being reduced by 8 times, Michaelis constant decreased 10 times, the lipase reuse times increased 2.25-fold compared to those in a batch reactor. In addition, the content of palmitic acid at sn-2 position (89.0%) and polyunsaturated fatty acids at sn-1, 3 positions (81.3%) are slightly improved compared to the product in a batch reactor. The increase of melting points (1.7°C) and decrease of crystallizing point (3°C) implied higher quality product was produced using the microfluidic technology. The main cost can be reduced from $212.3 to $14.6 per batch with the microreactor. Overall, the microfluidic bioconversion technology is promising for modified functional lipids production allowing for cost-effective approach to produce high-value microalgal coproducts.

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.