Preparation of DHA- and EPA-enriched Glycerides by Enzymatic Interesterification Using Tuna Oil and Capric Acid

Abstract

This study focused on the preparation of docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA) enriched-triacylglycerols by enzymatic interesterification using tuna oil and capric acid. The content of DHA+EPA is 26.86% in the tuna oil used in this study. A response surface methodology (RSM) was used to optimize the reaction parameters (reaction temperature, substrate molar ratio, enzyme amount and reaction time), and the optimized conditions were determined to be: reaction temperature 58 oC, substrate molar ratio (capric acid : tuna oil) 4:1, enzyme amount 4%, and reaction time 7.5 h. Under the optimized conditions, the content of DHA+EPA in the glycerides was 40.03%, which is 13.17% higher than that in raw tuna oil. In addition, the MLM-type structured lipids containing medium chain fatty acids (capric acid) at positions sn-1,3 and a long chain fatty acid (DHA/EPA) at the position sn-2 may have many health benefits for humans.