Novozyme 435 and Lipozyme RM IM Preferably Esterify Polyunsaturated Fatty Acids at the sn‐2 Position

Authors:
Publisher website
Google Scholar
Abstract
This work aims at studying the impact that the degree of unsaturation of fatty acids (FA) with the same chain length exerts on the esterification yield and the regiodistribution of FA in the glycerol backbone. To that end, triacylglycerols (TAG) are produced by esterifying several mixtures (stearic, oleic, and alpha‐linolenic acids) employing Novozyme 435 and Lipozyme RM IM. All esterifications achieve a high content of TAG (>69 mol%) with Lipozyme RM IM being more active. Both lipases initially esterify stearic acid, while linolenic acid is preferably esterified in the last step of the esterification. Additionally, the higher the degree of unsaturation, the higher the concentration at the position sn‐2. This trend is more marked for Novozyme 435. The structure of the FA causes steric hindrance resulting in competitive‐like behavior among the FA. Hence, the selectivity of lipases might be affected by the composition of the substrate.Practical Applications: Omega‐3 FA have a high nutritional value and are industrially employed to produce concentrates and structured or functional lipids. The regiodistribution of FA in the glycerol determines its bioavailability; those linked to the central position are more efficiently metabolized while those in the sn‐1 and sn‐3 positions are merely stored or excreted. Structured lipids are produced employing lipases, hence the regioselectivity of the lipases is a key point for the production. The results show that, for the same chain length, the regioselectivity of lipases can be affected by the composition of the substrate and that polyunsaturated FA tend to be esterified in the central position when employing Novozyme 435 and Lipozyme RM IM.

This publication has 31 references indexed in Scilit: