ABSTRACT Boneless, skinless chicken breasts were infused with grape seed extract (GSE), green tea extract (GTE), tertiary butylhydroxyquinone and a combination of GTE and GSE. Samples were irradiated and their physicochemical properties were assessed over 9 months of frozen storage (−20C). Irradiation did not affect pH or water-holding capacity. The effect of irradiation on the lightness value, L*, varied depending on storage time and infusion treatment. Irradiation increased redness (P < 0.05) except for samples infused with GTE (3,000 ppm). Irradiation increased maximum shear force, chewiness and hardness (P < 0.05) of cooked samples. Infusion of plant extracts increased lightness and decreased redness (P < 0.05), hardness and maximum shear force. The extent of lipid oxidation in all samples was determined by thiobarbituric acid reactive substances (TBARS) and carbonyl content methods. Irradiation increased both TBARS and carbonyl content in both raw and cooked chicken. Infusion with plant extracts decreased TBARS and carbonyl content compared with controls. PRACTICAL APPLICATIONS Although irradiation is considered a safe and effective means of ensuring the microbial safety of processed meat products, some physicochemical changes occur in the meat after irradiation that negatively affect the preservation of meat quality. Changes such as lipid oxidation and subsequent rancidity can possibly be inhibited with the use of antioxidants. Because of consumer preference for natural versus synthetic additives, natural products that have antioxidant activity could find application in products receiving irradiation treatments. It is the purpose of this study to ascertain the effect of processing with natural antioxidants found in green tea (GTE) and grape seed (GSE) extracts, which contain phenolic compounds such as catechin, epigallocatechin, epigallocatechin-gallate in GTE and procyanidins in GSE, on the physicochemical changes associated with irradiation of raw and cooked boneless/skinless chicken breasts. This preservation technology may find wide application in the meat processing industry as a means of reducing irradiation-induced quality deterioration.