Obtenção de lipídeos estruturados por acidólise enzimática em reatores de tanque agitado e leito fixo

Abstract

The present work aimed at the enzymatic synthesis of structured lipids, based on acidolysis of capric acid (C10) and grape seed oil, previously characterized in terms of peroxide and acidity indices, as well as compositional profile in fatty acids. The enzymatic route was chosen, using Rhizopus oryzae lipase (rROL) immobilized covalently in corncob powder. The corn cob powder in natura, samples from all stages of activation of the support, as well as the immobilized derivative were subjected to FTIR, SEM and elemental analyzes by EDS, in order to know the structure of the support. Experimental designs were used to evaluate the influence of temperature and pH on the hydrolytic activity of the free and immobilized enzyme. Biocatalysts in free and immobilized form were also characterized in terms of thermal stability, with an increase of about 30 times the thermal stability of the immobilized biocatalyst. The acidolysis reactions were carried out in agitated tank and fixed bed reactors. The products were analyzed for the degree of incorporation (GI) and peroxide index (IP). For stirred tank reactors, the reactions were carried out for 24 hours, with an average GI of 55 ± 0.3%. The reaction in a fixed bed reactor, with total recycling, was carried out for 120 hours, obtaining a maximum GI of 54.5% in 120 hours. Thus, it was found that the enzyme of Rhizopus oryzae was satisfactorily immobilized in corn cob powder. In addition, this enzyme showed potential for application in acidolysis reactions, aiming at obtaining structured triglycerides, since the degrees of incorporation obtained were satisfactory.