Novel nitrite-embedded packaging improves surface redness of dark-cutting longissimus steaks

The objective of this research was to determine the effects of nitrite-embedded/FreshCase packaging on lean color of dark-cutting beef. Eight dark-cutting (pH > 6.0) and eight USDA Low Choice (normal-pH; mean pH = 5.6) beef strip loins (longissimus lumborum) were selected 3 day after harvest. Each dark-cutting loin was sliced into five 2.5-cm thick steaks and randomly assigned to 1) dark-cutting steak packaged in polyvinyl chloride film (PVC) overwrap, 2) dark-cutting steak packaged in nitrite-embedded film, 3) dark-cutting steaks dipped in 0.2% rosemary solution and packaged in nitrite-embedded film, and 4) dark-cutting steak dipped in deionized water and packaged in nitrite-embedded film. The fifth dark-cutting steak was used to determine pH and proximate composition. Normal-pH choice loins were used as a control and each loin was randomly assigned to either PVC overwrap for retail display or to determine pH and proximate composition. Packages were placed in coffin-style retail display cases under continuous fluorescent lighting for 3 days. A HunterLab MiniScan XE Plus spectrophotometer was utilized to characterize steak color every 24 h. There was a significant treatment × storage time interaction (P < 0.05) for a* values and nitric oxide myoglobin formation. On days 1, 2, and 3 of the display, nitrite-embedded treatment improved (P < 0.05) redness compared to other dark-cutting steaks in PVC. A 45% increase in redness (P < 0.05) was observed for nitrite-embedded rosemary treatment over dark-cutting steak in PVC on day 3 of display. Nitric oxide myoglobin formation on day 0 was less for all dark-cutting steaks in nitrite-embedded packaging. Metmyoglobin content was greater (P < 0.05) on day 0 for dark-cutting steaks packaged in nitrite-embedded treatments than dark-cutting steaks in PVC. However, metmyoglobin level in dark-cutting steaks packaged in nitrite-embedded treatments decreased (P < 0.05) on day 1 compared with day 0. Dark-cutting steaks packaged in PVC had greater (P < 0.05) L* values on day 0 than other dark-cutting steaks in nitrite-embedded packaging. Conversely, on days 1, 2, and 3, there were no differences (P > 0.05) in L* values between dark-cutting treatments. Dark-cutting steaks in nitrite-embedded packaging had lower total plate count (P < 0.05) than dark-cutting steak packaged in PVC. The current research indicated that nitrite-embedded packaging has the potential to improve surface color of dark-cutting beef.