Abstract: In this study, phospholipase A1 was used to hydrolyze Antarctic krill phospholipids in aqueous media in order to obtain lysophospholipids rich in eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). The degree of phospholipid hydrolysis was measured by acid value. The composition of phospholipids was analyzed by high performance liquid chromatography (HPLC) and the acyl migration was further confirmed by measuring the content of glycerophosphatidylcholine (GPC). The fatty acid composition of phospholipids was analyzed by gas chromatographymass spectrometry (GC-MS). The results showed that the acid value increased firstly and then decreased with the increase of enzyme loading. As the hydrolysis proceeded, the content of Sn-2-lysophosphatidylcholine (Sn-2-LPC) increased initially and then reached an equilibrium value. The content of Sn-1-lysophosphatidylcholine (Sn-1-LPC) increased first and then decreased. This was due to the acyl migration of some Sn-2-LPC to form Sn-1-LPC, which was further hydrolyzed by LPA1 into glycerol phosphatidylcholine (GPC). Additionally in a short reaction period, temperature had no significant effect on the acyl migration. Finally, GC-MS analysis showed that the contents of EPA and DHA in the enzymatic hydrolysate Sn-2-LPC were relatively high, and the emulsion stability was also improved.

Key words: Antarctic krill phospholipid, lysophospholipid, phospholipase A1, acyl migration, aqueous media