Production of Oleic Acid Ethyl Ester Catalyzed by Crude Rice Bran (Oryza sativa) Lipase in a Modified Fed-batch System: A Problem and its Solution

Indro Prastowo (Postgraduate Program in Biotechnology, Postgraduate School, Gadjah Mada University, Jl. Teknika Utara, Barek Yogyakarta 55281||Indonesia Department of Biology Education, Faculty of Teacher Training and Education, Ahmad Dahlan University, Kampus III, )
Chusnul Hidayat (Postgraduate Program in Biotechnology, Postgraduate School, Gadjah Mada University, Jl. Teknika Utara, Barek Yogyakarta 55281||Indonesia Department of Food and Agricultural Product Technology, Faculty of Agricultural Technology, Gadjah Mada Universit)
Pudji Hastuti (Department of Food and Agricultural Product Technology, Faculty of Agricultural Technology, Gadjah Mada University, Jl. Sosio Justisia, Bulaksumur, Yogyakarta 55281)

Bulletin of Chemical Reaction Engineering & Catalysis
2015: BCREC Volume 10 Issue 3 Year 2015 (December 2015)

A fed-batch system was modified for the enzymatic production of Oleic Acid Ethyl Ester (OAEE) using rice bran (Oryza sativa) lipase by retaining the substrate molar ratio (ethanol/oleic acid) at 2.05:1 during the reaction. It resulted in an increase in the ester conversion of up to 76.8% in the first 6 h of the reaction, which was then followed by a decrease from 76.8% to 22.9% in 6 h later. The production of water in the reaction system also showed a similar trend. The water was hypothesized to lead lipase to reverse the reaction which resulted in a decrease in both (water and esters) in the last 6 h of the reac- tion. In order to overcome the problem, zeolite powder (25 and 50 mg/mL) were added into the reaction system at 5 h of the reaction. As the result, the final ester conversions increased drastically up to 90 - 95.7%. Thus, the combination of a constant substrate molar ratio (ethanol/oleic acid) during the reaction (at 2.05:1) with the addition of zeolite powder (25 and 50 mg/mL) to the reaction system at 5 h is effective for the enzymatic synthesis of OAEE. Copyright © 2015 by Authors, Published by BCREC Group. This is an open access article under the CC BY-SA License (https://creativecommons.org/licenses/by-sa/4.0).