scholarly journals Optimization of enzymatic synthesis of ethyl hexanoate in a solvent free system using response surface methodology (RSM)

Biocatalysis ◽  
2018 ◽  
Vol 4 (1) ◽  
pp. 14-26 ◽  
Author(s):  
Sarita D. Gawas ◽  
Nidya Lokanath ◽  
Virendra K. Rathod
Keyword(s):  
Response Surface Methodology ◽  
Response Surface ◽  
Solvent Free ◽  
Molar Ratio ◽  
Esterification Reaction ◽  
Enzymatic Esterification ◽  
Ethyl Hexanoate ◽  
Free System ◽  
Acid Ratio ◽  
Solvent Free System

Abstract The present paper demonstrates application of biocatalysis to the synthesis of ethyl hexanoate, i.e. pineapple flavour ester, in a solvent free system. In order to evaluate the effect of various process parameters on reaction conversion, response surface methodology (RSM) complemented by central composite design (CCD) was employed. A maximum conversion of 88.57% was obtained while changing one factor at a time, at optimum conditions of temperature (50 °C), enzyme dose (2%), molar ratio acid to alcohol (1:3), speed of agitation 250 rpm and reaction time of 120 min. Based on this RSM study, the optimum predicted conditions were: 1:3.39 alcohol to acid ratio, 2.35% enzyme loading and 48.83 oC, for a predicted conversion of 90.99%. The activation energy for the enzymatic esterification was determined and calculated to be 25.76 kJ/mol. The positive values of Gibbs-free energy (ΔG), enthalpy (ΔH) and negative value of entropy (ΔS) revealed that the esterification reaction was non-spontaneous and an endothermic reaction. The reaction seems to follow bi-substrate Ping Pong Bi Bi mechanism with inhibition by both substrates.

scholarly journals Optimization of the production of biodiesel by a commercial immobilized lipase in a solvent-free system using a response surface methodology

2008 ◽  
Vol 73 (2) ◽  
pp. 147-156 ◽  
Author(s):  
Nevena Ognjanovic ◽  
Dejan Bezbradica ◽  
Zorica Knezevic
Keyword(s):  
Response Surface Methodology ◽  
Response Surface ◽  
Reaction Rate ◽  
Immobilized Lipase ◽  
Statistical Significance ◽  
Solvent Free ◽  
Biodiesel Production ◽  
Molar Ratio ◽  
Free System ◽  
Solvent Free System

Response surface methodology was used for the evaluation of the effects of various factors on the synthesis of biodiesel catalyzed with immobilized lipase from Rhizomucor miehei in a solvent-free system. The production of biodiesel was optimized and model response equations were obtained, enabling the prediction of biodiesel production from the values of the four main factors. It would seem that the reaction temperature and the amount of water predominantly determined the conversion process while the methanol/oil molar ratio had no significant influence on the reaction rate. The temperature and amount of water showed negative interactive effects on the observed reaction rate per amount of enzyme. However, there were no significant interactions among the other variables according to the test of statistical significance. The highest yield of 10.15 mol kg-1 enzyme was observed at 45?C with a 6:1 methanol to oil molar ratio and with no added water in the system.

scholarly journals Optimisation and Characterisation of Lipase-Catalysed Synthesis of a Kojic Monooleate Ester in a Solvent-Free System by Response Surface Methodology

PLoS ONE ◽  
2015 ◽  
Vol 10 (12) ◽  
pp. e0144664 ◽  
Author(s):  
Khairulazhar Jumbri ◽  
Mohd Fahruddin Al-Haniff Rozy ◽  
Siti Efliza Ashari ◽  
Rosfarizan Mohamad ◽  
Mahiran Basri ◽  
...  
Keyword(s):  
Response Surface Methodology ◽  
Response Surface ◽  
Solvent Free ◽  
Free System ◽  
Solvent Free System
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