Efeito da suplementação de selênio na qualidade da carne de animais de produção

Abstract

Selenium is a mineral that plays an important role in the growth and maintenance of the animal organism, protecting membrane lipids against possible oxidative damage. Due to this characteristic, it has been incorporated into animal feed with a view to improving meat quality parameters. Existing studies point to a possible favoring of its use in broilers and swine, especially in parameters that are related to the loss of exudate, such as water retention capacity. However, there is no comparative study between all species reporting a significant improvement and whether the source (organic or inorganic) interferes with this improvement. Thus, the objective of this thesis was to compare the effects of selenium supplementation in production animals, aimed at slaughter, on meat quality characteristics. Therefore, a systematic literature review with meta-analysis was developed for broilers, pigs and fish (species chosen according to established inclusion criteria). In addition, a field trial was carried out with pirarucus (Arapaima gigas), in order to evaluate the parameters of quality and shelf life. Thus, the samples were subjected to yield analysis, instrumental texture, instrumental color, water retention capacity (CRA), drip loss (PG), cooking loss (PC), proximate composition, selenium content in fillets and Shelf Life. This consisted of analyzes of psychrotrophic aerobic heterotrophic bacteria, pH and total nitrogenous volatile bases (TVNB) over 22 days of refrigeration. The results of the meta-analytic study showed that selenium supplementation promotes improvements in some parameters. In broiler chickens it was found that the inorganic source acts positively in cooking loss, while the organic source in the water retention capacity. In pigs, improvements were seen in the drip loss, regardless of the source tested. In fish, the supplementation was negative, as it increased the hardness of the meat when the inorganic source was used. Corroborating these findings, the results obtained in the experimental trial with pirarucu (Arapaima gigas) indicated that there was no significant difference (p>0.05) for the parameters of fillet yield, instrumental texture, instrumental color and drip loss. As for PC, CRA and lipid content, there was a significant difference (p<0.05), for PC the lowest percentage was found in the organic selenium treatment (33.58%), contrasting the higher CRA that was observed in the control treatment (66.12%). The lipid content was higher in the control treatment, 2.67%. For the variable selenium content in fillets, greater muscle deposition was observed in the treatment with inorganic selenium presented at 492 µg/kg. With regard to shelf life, only for the variable TVNB there was a difference between storage times, with lower rates in the control treatment. The results of the analyzes that constitute the assessment of shelf life remained within the parameters established by legislation throughout the storage period. It is concluded that the strategy of inclusion of selenium in animal feed has shown positive results regarding certain quality parameters of pork and poultry meat. However, the use of selenium for the quality of fish meat needs to be better explored, testing different concentrations and supplementation times.