RESUMO
The objectives of this study were to evaluate the antioxidant capacity of peanut skin extract and its effect on the color and lipid oxidation of cooked chicken patties over 15 d of refrigerated storage. The extract was obtained using 80% ethanol and evaluated in terms of total phenolic content, reducing power based on the ferric reducing ability of plasma (FRAP) reagent, and 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity. The patties were made with ground thigh fillets, chicken skin, and 2% salt. They were homogenized and divided into the following two groups: a control treatment without antioxidants and a peanut skin treatment with 70 mg gallic acid equivalent (GAE)/kg per patty. Analyses of the fatty acid profiles, instrumental colors (L*, a*, and b*) and thiobarbituric acid reactive substances (TBARS) were performed on d 1, 8, and 15 of storage at 1±1ºC. The peanut skin extract resulted in a phenolic content of 32.6±0.7 mg GAE/g dry skin, an antioxidant activity (FRAP) of 26.5±0.8 6 µmol Trolox equivalent/g dry skin, and an efficient concentration (EC50) of 46.5 µg/mL. The total unsaturated fatty acid was approximately 73%, and 39% of this fatty acid content was monounsaturated. The peanut skin extract slowed the decrease in the a* values (P<0.05) but reduced the L* and b* values compared to the control samples during storage (P<0.05). Lipid oxidation was minimized by the peanut skin extract (P<0.05), which resulted in a maximum value of 0.97 malondialdehyde (MDA)/kg compared to values that were close 19 mg MDA/kg patties in the control sample at the end of storage period. Thus, it can be concluded that although peanut skin extract causes little color change, it can be applied as a natural antioxidant to cooked chicken patties because it efficiently inhibits lipid oxidation in this product during refrigerated storage.