Oleic acid enhancement in used frying palm oil via enzymatic acidolysis

Abstract

The extensive amount of used frying palm oil (UFO) generated in Malaysia has caused serious environmental problems. Management of the waste faces a significant challenge especially on choosing the appropriate method by considering the possibilities of contaminating the environment. This study aims to add value to UFO by producing high oleic palm oil. Enzymatic acidolysis using lipase was employed to incorporate oleic acid in the UFO. This study also investigated the effect of enzymatic loading, reaction time and water content on the properties of modified UFO as to find the optimum condition for oleic acid incorporation. Oleic acid incorporation was quantified based on peroxide and iodine values. The optimum conditions for acidolysis process were obtained at enzyme loading of 30% (w/w), reaction time of 24 hours, and water content of 2% (w/w) with substrate mole ratio of 1:2 (UFO: oleic acid) and temperature of 50 °C. At optimum conditions, the modified used frying palm oil (MUFO) has peroxide and iodine values of 19.00 ± 0.99 meq/mg and 31.5 ± 0.42 mg/mg, respectively. After the acidolysis reaction, oleic acid concentration has increased from 27.00 ± 0.70% (v/v) to 62.34 ± 1.29% (v/v), demonstrating their feasibility as a substrate for structured lipid production.