CRUZ, G. F.; http://lattes.cnpq.br/7419990285053972; CRUZ, Geoclecia Ferreira.
Resumen:
The use of immobilized lipase for esterification processes from vegetable oils leads to high yields of esters under mild operating conditions. Among the different media used in immobilization, chitosan, it is an organic support, or consisting of a natural polymer which has been widely used because of its low cost. It has been aimed at the application of Rizhomucor miehei lipase immobilized on chitosan aiming at its use in obtaining esters obtained from fatty acids from the hydrolysis of the Buriti oil (Mauritia flexuosa L. f .) with potential application in the pharmaceutical industry. It is important to conduct this study to promote an alternative use of regional products such as immobilization support, oils, contributing to the expansion and diversification of industrial biotechnology. Initially in carrying out this work was characterized chemically - physical buriti oil to assess the quality of the oil used. Thereafter was quantified free and immobilized enzyme activity assays prior to esterification, these being carried out from fatty acids obtained Buriti oil in different proportions ethanol, or in different molar ratios under stirring 150 rpm at 37ºC for 24 hours. The esterification assays were also performed with the presence of starch as adsorbent or desiccant. Being given the acidity of the initial reaction medium and end to find out what the income produced esters. The lipase in free form showed activity of 450,04 U/mL and immobilized form showed activity of 0,56 U/g. The burity oil showed relative density of 0,9213, moisture 0,23 %, acid value of 7,66 mg KOH/g, saponification number of 96,3 mgKOH /g and peroxide index value 12,84 mEq / 1000g , with results as that described in the literature. Yield 87% of fatty acids obtained was obtained. Maximum value conversion occurred in the tests carried out with the immobilized lipase in the ratio 1:1, 73,2% of esters formed in the reaction without desiccant and 80,12% conversion in the reaction medium in the presence of the agent. With the increase in molar ratio, there was a decrease in the esters formed because the increase of the ethanol used which prevents access to the active site fatty acids and remove the protective aqueous layer structure of the enzyme. As well, the starch used to prevent the presence of residual water formed in every molar ratios in the esterification reaction promoted hydrolysis of the esters formed by decreasing the conversion.