The influence of storage temperature and storage time on color stability, retail properties and case-life of retail-ready beef

Steaks from three different muscles were either vacuum or carbon dioxide pa cked and stored for up to 24 weeks at three different storage temperatures (-1.5, 2, or 5 degreesC). Following storage, they were displayed for up to 30 h. CIE color coordinates, the oxidative states of myoglobin and pH were measured and muscle color, surface discoloration, retail appearance, and od or were evaluated prior to storage and during display (0, 1, 2, 4, 6, 24 an d 30 h), and/or immediately prior to and following display. Prior to displa y, pH was negatively related to duration of storage, and samples stored at -1.5 degreesC had the highest and samples stored at 5 degreesC, had the low est pH. Perception of muscle color was influenced by duration of storage an d display, but lower storage temperatures appeared to produce a stabilizing effect. Both lightness of muscle color and deoxymyoglobin content were app arently not influenced by storage temperature or duration of storage or dis play. Both oxymyoglobin (OMB) and redness, as defined by CIE a* values, wer e lost progressively during storage and display, but this loss was progress ively lower as storage temperature decreased. Yellowness of muscle color, a s defined by CIE b* values, generally decreased as storage was prolonged, a nd this decrease was observed more quickly at higher storage temperatures. Surprisingly, b* values were not related to duration of display. Both surfa ce discoloration and metmyoglobin (MMB) content increased progressively dur ing storage and display. Samples stored at 5 degreesC displayed the most su rface discoloration, while samples stored at -1.5 degreesC contained the le ast MMB and displayed the least surface discoloration. Retail appearance de teriorated progressively during storage in all samples stored at 2 and 5 de greesC and in samples stored at -1.5 degreesC, which were displayed for at least 24 h. Retail appearance also deteriorated progressively during displa y in samples stored at -1.5 and 2 degreesC for three weeks or longer and in samples stored at 5 degreesC for 0 to 15 and 24 weeks. In unstored samples , samples to be stored at -1.5 degreesC generally received the lowest retai l appearance scores, but after prolonged storage and display, samples store d at -1.5 degreesC received higher retail appearance scores than samples st ored at 5 OC, particularly when samples were stored for 12 weeks or longer and displayed for 1 h or more. Odor deteriorated progressively during stora ge when measured both prior to display and after 30 h of display. In sample s stored for three weeks or longer, samples stored at -1.5 degreesC general ly received the lowest odor scores and were perceived to have the least pre valent off-odors. Samples stored at -1.5 degreesC maintained a retail case- life of 30 h, when stored for up to 17 weeks, while samples stored at 2 and 5 degreesC maintained a retail case-fife of 30 h, when stored for only eig ht and seven weeks, respectively. Consequently, storage life can be more th an doubled by storage at subzero temperatures (-1.5 degreesC). Canadian Cro wn Copyright (C) 2001 Published by Elsevier Science Ltd. All rights reserve d.