| dc.description.abstract | The objective was to evaluate the effects of high-pressure processing (HPP) levels on retail color, cooked color, and sensory attributes of dark-cutting beef. Eight USDA Choice (mean pH = 5.5; normal pH beef) and twelve dark-cutting (mean pH = 6.3) strip loins were obtained from a commercial packing plant within 2 d of harvest. Loins were cut into equal sections, vacuum packaged, and randomly assigned to HPP treatment of 0 (no HPP), 300, 450, and 600 megapascals (MPa). Following 48 hours of dark storage at 2°C, 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. Remaining steaks were vacuum packaged and frozen to evaluate cooked color and sensory attributes. The surface color readings were measured every 24 hours using a HunterLab MiniScan XE Plus spectrophotometer, while a trained color panel (n = 6) evaluated discoloration, paleness, and lean color on steaks. Oxygen consumption (OC), metmyoglobin reducing activity (MRA), and lipid oxidation were evaluated on d 0, 4, and 8 of retail display. Frozen steaks were thawed and cooked to an internal temperature of 68°C and tempered to 71°C. After cooking, steaks were randomly assigned for external color measurements using a HunterLab MiniScan spectrophotometer and Warner-Bratzler shear force measurements. A trained sensory panel (n = 6) evaluated initial juiciness, sustained juiciness, tenderness, beef flavor intensity, and overall acceptability. The data were analyzed using the Glimmix Procedure of SAS. There was a significant HPP level × day of retail display interaction for all instrumental color measurements. Throughout the retail display, L* values 450 and 600 MPa treated steaks were greater (P < 0.05) than 300 MPa and controls. When panelists evaluated lean color and discoloration, there was a significant pressure level × day of retail display interaction. Steaks treated at 300 MPa exhibited brighter red color and lower thiobarbituric acid reactive substance values than other pressure levels and normal pH control steaks (P = 0.0023). HPP did not affect (P > 0.05) initial juiciness, sustained juiciness, beef flavor intensity, or overall acceptability. High pressure had an impact (P < 0.05) on external cooked color. There was no difference in redness (a*) and red intensity (chroma) between HPP treated steaks and DC control steaks. In conclusion, low (300 MPa) and moderate (450 MPa) pressure levels did not affect sensory attributes nor impart a paler color to cooked steaks. The results indicate that 300 MPa can improve the redness of dark-cutting beef without affecting other quality parameters. | |
