Abstract
The aim of this research was to study the immobilization of lipase on chitosan by adsorption in order to examine the use of lipase as a catalyst in the transesterification of crude sunflower oil and Jatropha oil. The highest activity of immobilized lipase was found to be 857 U/g, and it corresponded to a glutaraldehyde concentration of 0.05%, pH 7, and a temperature of 37 °C. On the other hand, the activity of free lipase was 2,136 U/g. The optimum conditions for the transesterification of crude sunflower oil were as follows: oil-to-methanol molar ratio, 1:3; immobilized lipase, 100% (w/w of oil); water content, 20% (w/w of oil); shaking speed, 200 rpm; and temperature, 50 °C for 24 h. The maximum amount of methyl esters produced was 25%. When free lipase was used as the catalyst under the same conditions, the amount of methyl esters produced was 33%. The transesterification of Jatropha oil was also studied to compare the activities of the two types of lipases. Both types of lipases activate the tranesterification of sunflower oil more easily than the transesterification of Jatropha oil.
