Improvement of Color and Oxidative Stabilities in Nellore Bull Dark Meat in High-Oxygen Package by Lactate and Rosemary Oil Extract.

This study aimed to improve the color and oxidative stabilities of dark Nellore bull steaks with greater-than-normal ultimate pH (pH) by the injection (8% raw wet weight basis) of a solution with L-lactate (2.5%), phosphate (0.3%) and rosemary extract (0.06%), with further packaging in high oxygen atmosphere (HiOx MAP). muscles from pasture-fed Nellore bulls were divided into three pH ranges: normal (<5.80), intermediate (5.81-6.19), and high (≥6.2). Muscles were then halved, with sections were randomly assigned to non-enhanced (C, = 6/pH range) or injected (E, = 6/pH range) groups, at 72 h postmortem. Each section was cut into 2 cm-slices, which were HiOx-packed and then stored for 5 days (dark) and displayed for 9 days (fluorescent lighting) at 2 °C. Higher pH steaks exhibited greater a*, b*, h*, C* and surface oxymyoglobin and lower surface deoxymyoglobin and oxygen consumption compared to those of normal pH between days 0 and 5 ( < 0.05). Over the time, normal-pH muscles showed oxidative protection (lower TBARS and greater metmyoglobin reducing ability values, < 0.05) in enhanced-steaks. Therefore, enhancement and HiOx MAP seem to produce greater-than-normal pH Nellore bull steaks with a preferable color and quality, even after display time.