The nutritional and sensorial characteristics of chicken meat can be affected by oxidative rancidity, process of oxidation of lipids in the meat that constitutes one of the main forms of food deterioration. This problem may be prevented or reduced by adding antioxidants to the meat during the process of marination. In the present study, the addition of a polyphenol-rich quillay extract (QLPerm®) at 5 levels (0, 0.05, 0.10, 0.15, and 0.20%) to the marinade of chicken meat was evaluated. The marinated meat was stored under refrigeration (6 ºC) for 0, 2, 4, 6, and 8 days. Basal and induced lipid oxidation was evaluated by TBARS analysis. Microbiological quality was assessed by total coliforms and mesophillic aerobe counts. The application of this natural antioxidant reduced, in some cases, meat lipidic oxidation, improved its microbiological quality, and did not leave any perceivable residues as analyzed by a sensorial evaluation panel.
The addition of antioxidants to broiler diets has been shown to enhance their antioxidant status. Since boldo (Peumus boldus Mol.) leaves contain highly antioxidant molecules, a dried extract of boldo (DEB) was added to broiler diets to improve "in vivo" antioxidant tissue status and to favor animal growth. A DEB standardized for antioxidant content was prepared and added to poultry diets at three different levels (low-DELB, medium-DEMB, and high-DEHB) for a period of 6 weeks. A single negative control (no added antioxidant) and one positive control (supplementation with 200 mg/kg vitamin E) were used. Plasma antioxidant capacity (PAC), thiol content (GHS), and basal and induced lipoperoxidation of liver, leg and breast tissues were determined in birds at 2, 4, and 6 weeks of age. PAC increased with chicken age until week 6, but was unaffected by DEB addition at any level. However, DEB increased hepatic GSH content. No data indicated that DEB improved the resistance against induced lipoperoxidation in the assayed tissues. DEB contains compounds exhibiting high antioxidant activity "in vivo", as evidenced by the increase in liver thiol content. Regarding broiler performance, no differences in poultry body weight and feed consumption were detected during the assay.