Use of High-Pressure Processing to Improve the Redness of Dark-Cutting Beef

The objective was to evaluate the effects of high-pressure processing (HPP) levels on retail color of dark-cutting beef. Eight USDA Choice (mean pH = 5.5; normal-pH beef) and 12 dark-cutting (mean pH = 6.3) strip loins were obtained from a commercial packing plant within 2 d of harvest. Dark-cutting loins were cut into equal sections, vacuum packaged, and randomly assigned to 0 (no HPP), 300, 450, and 600 MPa of pressure for 90 s using chilled water. Following 48 h of dark storage at 2°C, dark-cutting loin sections were cut into 1.9-cm-thick steaks, placed in Styrofoam trays overwrapped in polyvinyl chloride (PVC) film, and placed in a simulated retail display for 8 d. The surface color readings were measured every 24 h using a HunterLab MiniScan XE Plus spectrophotometer, whereas a trained color panel (n = 6) evaluated discoloration, paleness, and lean color on steaks. Lipid oxidation was evaluated on day 0, 4, and 8 of retail display, and structural changes were determined using light microscopy on day 0 of display. There was a significant HPP level × day of retail display interaction for all instrumental color measurements. Throughout the retail display, L* values of 450 and 600 MPa applied steaks were greater (P < 0.05) than 300 MPa and controls. There was a significant pressure level × day of retail display interaction when panelists evaluated lean color and discoloration. Steaks treated at 300 MPa exhibited brighter red color and lower (P = 0.0023) thiobarbituric acid reactive substance values than other pressure levels and normal-pH control steaks. Light microscopy analysis indicated that HPP increased space between muscle structures. In conclusion, low (300 MPa) and moderate (450 MPa) pressure levels can improve redness of dark-cutting steaks.