| In conjunction with a study on centralized meat packaging, oxygen absorption kinetics of six commercial O2 scavengers was determined. The scavengers were placed in bags, which were filled with 240 mL of air, 4.5 L N2 + 15 mL of air, or 3.5 L CO2 + 9 mL of air, and the O2 concentration in each bag was measured at hourly intervals for 8 h. Significant (p < 0.05) variation existed in the O2 absorption rates among individual scavengers of the same type. In addition, effects of temperature, 25, 12, 2, and -1.5°C, and pack atmosphere, such as air and N 2 with initial O2 concentrations of 20% and 500 ppm, respectively, on their O2 absorption rates were significant (p < 0.05). In general, high temperatures and initial O2 concentrations gave faster O2 absorption rates than low temperatures and initial O2 concentration.; A retail-packaging system for centralized operations of retail-ready beef steaks or pork chops, was developed by evaluating 14 treatment combinations of retail packages. The presence of O2 scavengers inside a lidded or over-wrapped retail tray having an absorbent pad or a grid or both, was necessary to prevent discoloration of meat cuts. In a subsequent experiment, the amount of O2 absorbing capacity required in each retail tray was determined. A minimum of eight O2 scavengers sachets with O 2 absorption rate high enough to deliver an O2 half-life of 0.6--0.7 h in the pack atmosphere where O2 concentration remains ≤500 ppm at any time of storage, were required in each retail tray.; Master-packaged steaks, under 100% N2 atmosphere, with or without O2 scavengers were stored at 1 +/- 0.5°C for up to 8 days. After a subsequent storage interval of 1 day, 3 master packs containing steaks packaged with or without O2 scavengers were opened and examined for visual characteristics and chemical states of myoglobin. It was concluded that to prevent transient discoloration of beef steaks, the O2 concentration should be reduced to 0 ppm at 1 +/- 0.5°C within 3-h of pack closure.; The beef steaks were master-packaged under 100% N2 atmosphere and were stored for up to 10 weeks. After subsequent storage intervals of 1 week, 2 master packs were opened and steaks were analyzed for visual, odor, flavor, and microbiological characteristics. In addition, reflectance spectra were obtained from the steaks' surface to estimate chemical states of myoglobin. These steaks were further displayed in a retail display case for 4 days, and were analyzed daily for visual characteristics and chemical states of myoglobin. On the 4th day of retail display, odor, flavor, and microbiological characteristics were also determined. Retail appearance was the limiting factor for the retail display life of the steaks. The present system can deliver a storage life of 10 weeks, with a subsequent retail display life of 3 days for master-packaged beef steaks. |
