Araujo K.L.G.V.,Federal University of Paraiba |
Epaminondas P.S.,Federal University of Paraiba |
Silva M.C.D.,Federal University of Maranhão |
De Lima A.E.A.,Laboratorio Of Combustiveis E Materiais Lacom |
And 7 more authors.
Journal of Thermal Analysis and Calorimetry | Year: 2011
Physicochemical and thermal analyses were undertaken to evaluate the influence of the temperature on the oxidation of sea fish oil once its polyunsaturated fatty acids deteriorate rapidly. Fish oil displayed four decomposition steps in synthetic air atmosphere and only one step in nitrogen atmosphere. The first step started at 189 and 222 °C for oxidizing and inert atmospheres, respectively. An OIT value of 53 min was measured at 100 °C. After the degradation process the peroxide index and the iodine index reduced from 35.38 to 9.85 meq × 1000 g-1 and from 139.79 to 120.19 gI2 × 100 g-1, respectively. An increase of the free fatty acids amount from 0.07 to 0.17% was observed while viscosity increased from 57.2 to 58.0 cP. Absorption at 272 nm also increased. The thermogravimetric and spectroscopic techniques are reproducible and versatile being an option for characterization of edible oil oxidation. © 2011 Akadémiai Kiadó, Budapest, Hungary.