LIPID PEROXIDITION DELAY BY ANTIOXIDANT HYDROLYSATES IN CHICKEN HOMOGENATES

Lipid peroxidation is a form of meat spoilage that has implications on the product's sensory and microbiological quality. Artificial antioxidants are used industrially to delay the peroxidation process and the formation of free radicals. Their use has been questioned based on food safety issues, stimulating the search for natural antioxidants. Most natural antioxidants, however, are plant related hydrophilic phytochemicals, such as phenolic compounds, which hinders their application in meat products. The main goal of this work was to evaluate the ability of powdered egg white protein hydrolysates to delay lipid peroxidation in chicken homogenates when compared to other methods of preservation: synthetic antioxidant (BHT) or frozen storage. Chicken homogenates were prepared by mechanical homogenizing the thighs and drumsticks from which the skin and bones were manually removed. The homogenate was aliquoted into 40 g samples that were added with hydrolysates (0.1 or 0.2%) or BHT (0.1%) and stored under refrigeration (8ºC) for 14 days. Two controls, without antioxidants, were also evaluated: at 8º and at - 20ºC. Lipid peroxidation was determined, after 1, 2, 7, 10 and 14 days of storage, by the extraction and colorimetric quantification of thiobarbituric acid reactive substances and expressed as malonaldehyde equivalents (EqM = ng MDA/Kg). All samples presented less EqM than the control that was kept under refrigeration and more than the frozen control. Among the samples with antioxidant, at the same concentration, the hydrolysate added samples presented no significant difference from the BHT added ones, and higher hydrolysate concentrations (0.2%) resulted in significantly less EqM after 7 and 10 days of refrigerated storage, when compared to BHT (0.1%) preserved samples. Our results strongly suggest that the tested hydrolysates may be applied as meat products preservatives in concentrations similar to those used for artificial antioxidants.