Avaliação da estabilidade de vitamina C encapsulada em amostras de ração para aves obtidas por extrusão

Abstract

Brazil is the world's leading exporter of chicken meat and taking an internal market similar to that of China (the country with six times the population of Brazil), interest in improving the zootechnical parameters in the production of poultry is fact. The mortality by the stress is a phenomenon that has been studied and reported in the literature, however, there is interest in improving the survival rates. Among the alternatives, vitamin C exerts an antioxidant action in the living organism by reducing the animal stress. The development of animal feed is an appropriate mechanism to try to introduce the animal susbstâncias that may help with the levels of stress caused by extreme temperatures and high densities, lower levels of stress generated by the production of free radicals. Due to the termolability of vitamin C, to produce a feed with this compound may involve complex and its loss to keep it intact in its properties when using the extrusion process due to high temperatures that are employed therein. The objective of this study was the testing two different products of vitamin C encapsulated: Biocitro® AA and Biocitro® Powder PG in different conditions of extrusion processing. The experimental design allowed evaluating the parameters and their relation with the results using the response surface methodology. The parameters evaluated: moisture, temperature and screw speed rotation where used to verify the stability of encapsulated products with vitamin C in the feed poultry formulation. Results in the extruded formulations showed the water solubility index (WSI) which were affected significantly (p <0.05) by the square coefficient of barrel temperature. For the water absorption index (WAI), it was found that other factors influenced the response. For all treatments were the common linear effect of moisture and the processing screw speed, there were significant differences (p <0.05). Treatment using Biocitro® AA (T1) allowed optimizing the processing parameters with a high regression coefficient (0.81359), obtaining the 147ºC barrel temperature, 18.5% moisture and 170rpm speed screw, to achieve optimal levels of water absorption index. Analytical results with high performance liquid chromatography detected no measurable levels of vitamin C in any of the treatments. Thus, the addition of vitamin C encapsulated in the form of Biocitro® AA and Biocitro® Powder PG in order to ensure the inclusion of vitamin C in the formulations, under treatments studied is not a procedure that can guarantee the presence of vitamin C in formulations for extruded feed poultry.