Enzyme Kinetic of Lipase Catalysed Acidolysis of Used Cooking Palm Oil

Abstract

Enzymatic acidolysis of various fats and oils has successfully shown a promising ability to alter specific positions of lipids and incorporate desirable fatty acids at specific positions. However, used cooking oil utilization for enzymatic acidolysis is still lacking scientific investigation. Hence, this study aims to utilize used cooking palm oil (UCPO) by enhancing the oleic acid content via enzymatic acidolysis using immobilized C. rugosa lipase. The optimum substrate molar ratio (mol/mol) was identified based on the analysis of the peroxide, iodine, and acid values. Then, kinetic parameters, Km and Vmax for the enzymatic acidolysis of UCPO were calculated. Substrate molar ratio of 1:1, 1:2, 1:3, 1:4, and 1:5 mol/mol (oil: acid) was varied to evaluate the peroxide, acid, and iodine values. The reaction conditions such as reaction temperature (50 °C), reaction time (24 hours), enzyme concentration (0.05 g), agitation speed (250 rpm), and pH (7) were fixed throughout the experiment. The Michaelis-Menten kinetic model was selected to describe the kinetic of enzymatic acidolysis of UCPO. The result showed that incorporation of oleic acid in UCPO has been successfully achieved with the increased in IV value from 39.47 I2/g to 110.53 I2/g. The optimum substrate molar ratio obtained was 1:3 mol/mol with the highest iodine value of 110.53 I2/g. The best linear regression approach is Lineweaver-Burk plot with the values of Vmax and Km were 34.5658 μmol/ml.min and 0.06 mol/L, respectively. The enzyme activity for C. rugosa lipase was obtained at 0.5804 μmol/min.ml.