14A-33

G. TEWARI, Biosytems Engineering, University of Manitoba, Winnipeg, MB R3T5V6, Canada, L. E. Jeremiah, Meat Research, Agriculture and Agri-Food Canada, Lacombe, AB T4L 1B2, Canada, D. S. Jayas, Biosystems Engineering, University of Manitoba, Winnipeg, MB R3T 5V6, Canada, and R. A. Holley, Food Science, University of Manitoba, Winnipeg, MB R3T 2N2, Canada.

Concerted effort is required to identify a suitable packaging system for centralized meat distribution. The package system should reduce or eliminate problems associated with development of transient or permanent meat discoloration due to residual O₂.

The present study was designed to identify a suitable packaging system for such commercial operations.

A series of 3 experiments was performed in the study. I: Beef steaks or pork chops were placed into a lidded retail tray having one of 12 treatment combinations ± O₂ scavengers. II: Beef steaks were placed in lidded or over-wrapped retail trays with 8 O₂ scavengers underneath an absorbent pad ± an underlying plastic grid. III: Beef steaks were over- wrapped in retail trays with 2, 4, 6, or 8 O₂ scavengers underneath an absorbent pad. Retail trays were placed in master packs under 100% N₂ and stored at 2 or -1.5°C for 1 week. Meats were then evaluated for visual characteristics using a trained panel and for metmyoglobin content using a reflectance spectrophotometer.

Experiment I: The steaks or chops packaged with O₂ scavengers had lower discoloration scores, higher retail appearance scores, and lower metmyoglobin content (<7%), than the meats packaged without O₂ scavengers (p<0.05). Experiment II: Steaks packaged in lidded or over-wrapped trays with or without a grid had comparable (p>0.05) retail appearance scores, <10% metmyoglobin, and no discoloration. Experiment III: Steaks packaged with 8 O₂ scavengers had the lowest discoloration scores, the highest retail appearance scores, and the lowest metmyoglobin content (<20%) when compared to steaks packaged with £ 6 O₂ scavengers(p<0.05).

The most effective and economical treatment combination for use in master packaging systems was a plastic retail tray with an absorbent pad and 8 O₂ scavengers inside the retail tray underneath an absorbent pad.