Sintesis Ester Metil Rantai Medium dari Minyak Kelapa dengan Cara Metanolisis Kimiawi

Abstract

Synthesis of fatty acid methyl ester from coconut oil has conducted by chemical methanolysis. The objectives of the research were to evaluate the effect of temperature reaction on yield and profile of fatty acid methyl ester and the fractionation process on medium chain fatty acids methyl ester content. Coconut oil was extracted from 11-12 months of Mapanget Tall coconut variety fruit. The oil was then analyzed to evaluate the physycochemical properties and fatty acids profile. Methanolysis reaction was conducted using potassium metoxide as a catalyst at 50, 55 and 60^oC for 2 hours. The methanolysis products were then measured for the yield and were determined for fatty acids profile. Furthermore, the fatty acid methyl ester was franctionated by melting from solid to liquid form. The results showed that the coconut oil had a good quality and medium chain fatty acid content was 61.93%, whereas lauric acid was the major component about 48.24%. The yield of fatty acid methyl ester was 85.41-86.69% and medium chain methyl ester content were 60.81%, 61.84% and 59.85% at reaction temperature of 50^oC, 55^oC and 60^oC, respectively. Ester methyl lauric was a major component of 48.84 – 49.04%. Dry fractionation process only increased 6.68% of fatty acids methyl laurate content.

ABSTRAK

Pada penelitian ini dilakukan sintesis ester metil asam lemak minyak kelapa dengan cara metanolisis kimiawi. Tujuan dari penelitian ini adalah mengetahui pengaruh suhu metanolisis terhadap yield dan profil ester metil asam lemaknya serta perlakuan fraksinasi terhadap kandungan ester metil asam lemak rantai medium. Minyak kelapa diekstraksi dari daging buah kelapa varietas Dalam Mapanget umur buah 11-12 bulan. Minyak kelapa yang diperoleh dianalisis sifat kimianya dan profil asam lemaknya. Reaksi metanolisis dilakukan secara kimiawi menggunakan katalisator kalium metoksida pada suhu 50, 55 dan 60^oC selama 2 jam. Hasil metanolisis diukur yield dan proporsi asam lemaknya. Selanjutnya ester metil yang dihasilkan difraksinasi dengan metode beku ke cair. Hasil analisis diperoleh bahwa minyak kelapa mempunyai kualitas yang baik dan asam lemak rantai medium sebesar 61,93% yang didominasi oleh asam laurat sekitar 48,24%. Yield ester metil yang dihasilkan berkisar 85,41-86,69% dengan total kandungan ester metil rantai medium yang dihasilkan berturut-turut 60,81%, 61,84% dan 59,85% masing-masing pada suhu 50^oC, 55^oC dan 60^oC. Proporsi tertinggi adalah ester metil laurat yaitu sebesar 48,84 - 49,04%. Proses fraksinasi kering dengan metode beku ke cair hanya dapat meningkatkan proporsi ester metil laurat sebesar 6,68%.