Antioxidant Extracts from Acorns (Quercus ilex L.) Effectively Protect Ready-to-Eat (RTE) Chicken Patties Irrespective of Packaging Atmosphere

This study evaluated the impact of a phenolic-rich acorn extract (200 ppm gallic acid equivalents) and the concentration of oxygen in the packaging system (low-oxygen modified atmosphere; 5% vs. normal-oxygen; 21%) on lipid and protein oxidation and consumers acceptance of the ready-to-eat chicken patties. Samples were subjected to cooking (electric oven, 170 degrees C/16 min), cold storage (14 d at 4 degrees C), and reheating (microwave, 600 mW/1 min). Samples treated with acorn extract kept thiobarbituric acid-reactive substances numbers and lipid-derived volatiles at basal levels throughout the whole processing irrespective of the oxygen concentration in the packaging atmosphere. Consistently, treated patties had lower protein carbonyls than control ones. The acorn extract also controlled color and texture deterioration during chilled storage and reheating and improved the color and odor acceptance of the products. Formulating with acorn extract is a feasible strategy to inhibit the oxidation-driven changes and preserve the quality of reheated samples as if there were freshly cooked. Compared to the effect of the antioxidant extract, the concentration of oxygen in the packaging system was negligible in terms of quality preservation.