Enzymatic Transesterification of Fish Oil and Milk Fat for The Synthesis of Structured Lipids: Study on The Effect of Reaction Time and Temperature

Abstract

Structured lipids (SLs) dominated by polyunsaturated fatty acids (PUFAs) in sn-2, whereas at sn-1,3 are dominated by saturated fatty acids (SFAs) have good nutritional properties. This study was aimed to synthesize these SLs through enzymatic transesterification of fish oil with milk fat. The factors such as reaction time and temperature were studied. Transesterification reaction was carried out using a catalyst of Candida antarctica lipase. The results showed that at the longer reaction time and higher temperatures caused acyl migration, where PUFAs shifted from sn-2 to sn-1,3 from glycerol backbone, changed by SFAs. The optimal transesterification was reaction time for 4 h at 30 °C, resulted in SLs that sn-2 was incorporated by oleate, eicosapentaenoic acid (EPA), and docosahexaenoic acid (DHA) were about 21.4, 6.7, and 2.1% respectively. In contrast, sn-1,3 were incorporated by SFAs such as caprate, laurate, myristate, palmitate, and stearate were about 3.6, 6.7, 16.9, 30.4, and 7.6%, respectively. SLs consisted of 95.20% in the form of triacylglycerol (TAG), while diacylglycerol (DAG) and monoacylglycerol (MAG) were about 2.95% and 1.85%, respectively. SLs can potentially be applied to the fortification of dairy products.

Keywords: Browning, caramelization, Maillard reaction, sugar, amine group