Aproveitamento de cabeça de tilápias nilóticas (Oreochromis niloticus) para a produção de óleo de peixe - obtenção, refino e avaliação

Abstract

Fish can undergo a number of different processing, making this raw material an excellent commoditie food leading to a wide range of tastes and presentations. The residues are leftovers and by-products that originate from the process of industrialization of a given product. In the case of tilapia, the filleting process generates an amount of meat to be commercialized, which usually turns around 17% to 30%, and there are some cases of use of 34% to 45%. The fatty acids present in other oils and fats are also present in fish oil, which are polyunsaturated long chain fatty acids. Throughout the process of industrialization and storage, depending on temperature and luminosity, fish oil may suffer changes due to the presence of fatty acids, which leave it subject to oxidative processes. Oxidation reactions occur by formation of free radicals and are characterized by an induction period, followed by an accelerated absorption of oxygen, and end with the production of peroxides, rancidness, odor and other polymerization products. One way to avoid autoxidation of fats and oils would be to reduce the incidence of all the factors that favor it, keeping to the minimum the energy levels (temperature and light) that trigger the process of free radical formation. Thus, the objectives of the present study were to extract and purify nilotic tilapia oil from head residues evaluating different storage temperatures in relation to the extraction as well as storage time and the type of packaging on its quality. Physico-chemical analyzes of peroxides, saponification, refraction, acidity and iodine and physical color and rheology analyzes were performed. The results showed that the different temperatures evaluated did not interfere with the final product and that the dark package was more suitable for the adequate storage of the oil, thus prolonging its useful life.