Optimization of enzymatic methanolysis of soybean oil by response surface methodology

Demirkol S., AKSOY H. A., Tuter M., USTUN G., SASMAZ D. A.

JOURNAL OF THE AMERICAN OIL CHEMISTS SOCIETY, vol.83, no.11, pp.929-932, 2006 (SCI-Expanded) identifier identifier

  • Publication Type: Article / Article
  • Volume: 83 Issue: 11
  • Publication Date: 2006
  • Doi Number: 10.1007/s11746-006-5048-4
  • Journal Name: JOURNAL OF THE AMERICAN OIL CHEMISTS SOCIETY
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Page Numbers: pp.929-932
  • Keywords: alcoholysis, biodiesel, lipase, optimization, response surface methodology, Rhizomucor miehei, soybean oil, LIPASE-CATALYZED BIODIESEL, CANDIDA-ANTARCTICA LIPASE, FUEL PRODUCTION, TRANSESTERIFICATION, ESTERS
  • Istanbul Technical University Affiliated: Yes

Abstract

Enzymatic methanolysis of refined soybean oil with methanol was investigated using Rhizomucor miehei lipase, Lipozyme RM IM, in n-hexane for reaction times of 30 min. Response surface methodology (RSM) based on three-level, three-factor (variable) face-centered cube design was used for the optimization of methanolysis. The independent variables that affect the methanolysis reaction conducted in n-hexane are temperature (degrees C), enzyme/oil weight ratio, and oil/methanol molar ratio. A good quadratic model was obtained for the methyl ester production by multiple regression and backward elimination. A linear relationship was observed between the observed and predicted values (R-2 = 0.9635). The effects of temperature and enzyme amount, which affected methyl ester content of the product (response) positively, were significant (P < 0.01). The quadratic term of temperature and the interaction term of enzyme amount with temperature affected the response negatively (P < 0.01). The interaction term of conditions for the response at which methyl ester content of the product was 76.9% were determined to be 50 degrees C, 2.37 methanol/oil mole ratio, and 0.09 enzyme/oil weight ratio.