The influence of packaging and storage time on the retail properties and case-life of retail-ready beef

Steaks from three different muscles were either vacuum (V) or CO2 (CAP) packed and stored for up to 24 weeks at three different storage temperatures. Following storage they were displayed for up to 30 h. Muscle pH declined during storage in both package types. Color became progressively darker during storage, but muscle color was not related to duration of storage. Muscle color was dependent upon package type during storage. Lightness (L*) values were not related to duration of storage or display, but CAP samples were generally lighter in color than V samples. Package type generally exerted little influence on deoxymyoglobin (DOMB) content, but V samples generally contained more DOME than CAP samples, prior to display. Although package type exerted little influence on a* values V samples generally contained more oxymyoglobin (OMB) than CAP samples. Redness of muscle color (a* values) and OMB were both lost progressively during storage and display, irrespective of package type. Yellowness (b* values) was not influenced by package type, but yellowness was progressively lost in both package types during storage. However, b* Values were not related to duration of display. Although type of packaging exerted little influence on surface discoloration, CAP samples generally contained more metmyoglobin (MMB) than V samples during display. Both MMB content and surface discoloration increased progressively during storage and display, irrespective of package type. Retail appearance deteriorated progressively during storage in samples subsequently displayed for at least 1 h, irrespective of package type. Retail appearance also deteriorated progressively during display in all V samples and in CAP samples peviously stored for at least 3 weeks. Only a few differences in retail appearance attributable to package type were detected, and these differences were inconsistent. Off-odors became progressively more prevalent during storage, irrespective of package type. V samples generally had more prevalent off-odors than CAP samples. CAP samples retained a retail case-life of 30 h after being stored for 13 weeks or less, while V samples retained a retail case-life of 30 h after being stored for only 8 weeks or less. This 5-week difference in storage life, based upon visual appearance, could well have important practical implications. Crown Copyright (C) 2001 Published by Elsevier Science Ltd. All rights reserved.