Antioxidantes naturais e sintéticos em alimentos completos para cães: uma análise comparativa

Abstract

The oxidative stability of dog foods is a key factor in preserving their nutritional and sensory quality during storage. This study aimed to evaluate the effect of synthetic and natural antioxidants, with and without vitamin E, on the physicochemical stability of dog foods stored for 210 days. Four experimental diets were formulated: control (without antioxidant), with BHT (synthetic antioxidant), and with a blend of natural antioxidant compounds (green tea, rosemary and essential oils), tested both with and without vitamin E. The formulations were analyzed for proximate composition, water activity, lipid oxidation (TBARS, peroxide value, and acidity index), and accelerated oxidative stability (Oxipres®). The results indicated that all treatments remained within the nutritional standards recommended for commercial dog foods, with only slight variations during storage. The addition of antioxidants contributed to a better preservation of crude protein, crude fiber, and moisture, as well as assisting in the control of water activity, which remained below the critical limit of 0.60, ensuring microbiological and physicochemical stability. Lipid oxidation markers showed significant differences among treatments. The control group presented the highest values, confirming the quick progression of oxidation in the absence of antioxidants. BHT proved to be an efficient antioxidant, consistently maintaining lower values. Natural antioxidants also reduced oxidation compared with the control, and the presence of vitamin E enhanced their efficacy, resulting in performance statistically similar to BHT at certain storage periods. The accelerated evaluation by Oxipres® confirmed that antioxidants delayed oxidation, although natural compounds showed greater susceptibility after long storage periods. Therefore, it can be concluded that the use of antioxidants is essential for preserving oxidative stability and nutritional quality of extruded dog foods. BHT demonstrated higher efficiency, but the combination of natural antioxidants with vitamin E represents a promising technological alternative, especially considering the growing demand for natural ingredients in the pet food sector. The findings reinforce the need for further studies on concentrations, synergistic combinations, and processing conditions to maximize the effectiveness of natural antioxidants without compromising the quality and safety of the final product.