77 Improving lean muscle color of atypical dark- cutting beef by antioxidant-enhancement and modified atmospheric packaging

Abstract

Abstract Any deviation from the bright-red color of beef leads to discounted price or consumer rejection. Atypical dark-cutting beef represents darker color of lean around a pH 5.6 – 5.8. However, limited studies have determined the postharvest practices to improve the lean color of atypical dark-cutting beef. Therefore, the objective was to evaluate the effects of rosemary-enhancement and modified atmospheric packaging on atypical dark-cutting beef. Atypical dark-cutting beef strip loins (n = 13, pH=5.70 ± 0.09; ADC) and USDA Choice beef strip loins (n = 6, pH=5.57 ± 0.1; CH) were selected within 72 h of harvest. Atypical dark-cutting strip loins were divided into 2 sections, and randomly assigned to one of the following enhancement treatments: control non-enhanced (ADC), or a 1.1% rosemary-enhanced treatment (ADCE). After enhancement, 2.54 cm steaks were cut from CH, ADC, and ADCE strip loins and assigned to 1 of 3 packaging treatments: polyvinyl chloride overwrap (PVC), carbon monoxide modified atmosphere packaging (CO-MAP; 0.4% CO, 69.6% N, and 30% CO2), and high-oxygen modified atmospheric packaging (HiOx-MAP; 80% O2 and 20% CO2). A HunterLab MiniScan was used to determine color during the 6 d simulated retail display. Visual color measurement for muscle darkening (MD), muscle color (MC), and surface discoloration (SD) were recorded on d 2, 4, and 6 of retail display. There was a significant enhancement x packaging interaction for instrumental and visual color measurements. For all packaging types, ADCE steaks possessed greater L* values than DC steaks. In addition, ADCE steaks packaged in HiOx-MAP or CO-MAP had brighter-red color than ADC steaks. Furthermore, ADCE and C steaks had less muscle darkening compared with ADC steaks for MD and MC attributes. The results suggest that enhancement and modified atmospheric packaging have the potential to improve the surface color of atypical dark-cutting beef.