Synthesis of human milk fat substitutes based on enzymatic preparation of low erucic acid acyl-donors from rapeseed oil

Abstract

Rapeseed oil has a similar oleic acid/linoleic acid ratio to human milk fat (HMF). However, it can hardly be used for human milk fat substitute (HMFS) synthesis due to high erucic acid content. In this study, Candida cylindracea lipase (CCL) was found to strongly discriminate against erucic acid. Free fatty acids containing low erucic acid and high oleic acid and linoleic acid were prepared from rapeseed oil hydrolysis catalyzed by CCL. The erucic acid content was only 1.58% (initial 8.70%), when the degree of hydrolysis reached 79.58%. The free fatty acids were used as acyl-donors in the acidolysis catalyzed by Novozym 40086. Considering acyl incorporation and migration, the optimum conditions were 1:8 (tripalmitin to acyl-donors), 40 °C and 2 h. The erucic acid content dropped to 0.97% in the HMFS. According to the Q-TOF-MS analysis, the HMFS was rich in 1,3-dioleoyl-2-palmitoyl-glycerol (18.20%) and 1-oleoyl-2-palmitoyl-3-linoleoyl-glycerol (17.96%), which was similar to HMF.