Estudo da utilização de lipases no enriquecimento de oleos de sardinha e Mucor sp em acidos graxos poliinsaturados

AUTOR(ES)
DATA DE PUBLICAÇÃO

1998

RESUMO

The present work reports the study of the hydrolysis and etherification reactions catalyzed by microorganism lipases, which were isolated at the "Laboratorio de Bioquímica de Alimentos - FEA - UNICAMP", belonging to Rhizopus sp, Geotrichum sp, Aspergillus sp and the commerciallipase Candida cylindracea. The aim was the enrichment of polyunsaturated fatty acids (PUF A) on sardine oil (Sardinella brasiliensis) and fungal oil from Mucor sp. The lipases of Rhizopus sp (1,3 - positional specificity), Geotrichum sp (specific for the long chain fatty acids with cis double link on position 9) and Candida cylindracea (unspecific positionally), chosen for the study, provided an expressive increase in the concentration of gamma-linolenic acid (GLA) on the fungal oil from Mucor sp and in the concentration of eicosapentaenoic (EPA) and docosahexaenoic (DHA) acids on sardine oil. The fractions of glycerides and free fatty acids, obtained from an enzymatic action, were separated by thin-layer chromatography (TLC), quantified by thin layer chromatography - flame ionization detector (TLC-FID) and had the fatty acids composition analyzed by gas chromatography (CG). The lipase from Rhizopus sp, in optimum reaction conditions, was found to be the most efficient for the hydrolysis reaction among all the lipases tested. This lipase hydrolyzes the substrate oil from Mucor sp much more efficiently than the sardine oil. After 8 hours of hydrolytical reaction, 18.5% of GLA were obtained, in relation to all the fatty acids that compose the oil from Mucor sp (original oil contains 11.4% of GLA). Candida cylindracea s lipase showed high efficiency for the hydrolysis catalysis of sardine oil. DHA’s concentration was doubled after 16 hours of hydrolytical reaction while EPA’s concentration increased 35 % in relation to the situation before the hydrolysis. Geatrichum candidum s lipase showed a low hydrolytical activity for the analyzed substrates, but a high etherification capability. This enzyme esterificated chiefly monounsaturated fatty acids with buthanol and GLA s concentration in the unesterificated fatty acids of the oil from Mucar sp increased 3.4 times if compared to the situation before the reaction. Microorganisms lipases were found to be less effective in the esterification, when glycerol was used at the analyzed conditions. In the formed glycerides (triglyceride, diglyceride e monoglyceride), which were separated by thin-layer chromatography and analyzed by gas chromatography, not a sufficient quantity of polyunsaturated fatty acids was found to make the enrichment possible.

ASSUNTO(S)

esterificação (quimica) lipase hidrolise acidos graxos

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