ESTABILIDADE OXIDATIVA DO BIODIESEL METÁLICO DO ÓLEO DE GIRASSOL DO TIPO CONVENCIONAL E ALTO OLEICO

Abstract

The oils and their products are likely to suffer oxidation due to its composition of saturated and unsaturated fatty acids. Among the known products, oil and biodiesel obtained from sunflower, are one of the values that have lower oxidative stability. This paper aims to study the oxidative stability of the conventional type sunflower oil and high oleic, from its cultivation, crude vegetable oil production, processing into biodiesel and physicochemical characterizations of crude vegetable oil and biodiesel, checking their quality second standards. We selected three genotypes of the conventional type and two high oleic type for mechanical extraction of the cold oil, vegetable oil and subsequently underwent transesterification reaction via methyl route using homogeneous catalysis. The oils were within the standards for moisture, density, acid number, saponification number and iodine value. Biodiesel from all samples were within the rules on physical chemical characterization of pH, specific gravity, acid number, saponification number and iodine value. The oil and biodiesel derived from sunflower presented as characteristics, low values of oxidative stability, but the high oleic oil type (SYN 3950 and SYN 39A) and its biodiesel had higher oxidative stability compared with the samples of the conventional type. The alternative test antioxidants (Vitamin E and BTAH) showed that each antioxidant acts as its own characteristics, which may also act as proantioxidant accelerating the oxidation reaction, as in the case of BTAH. For the analyzes with Vitamin E at concentrations of 500 and 1000 ppm there was an increase in oxidative stability of the sample, while 1500 ppm, 7, 8, and 9% decreased the oxidative stability.