Quarter-pound, ground beef patties were either packaged in polyethylene bags or vacuum packaged. Packaged samples were stored at -12, -23 and -34°C for 20 weeks. At 4 week intervals, samples were thawed and their drip loss, cooking loss and objective color were measured. The rate of change of these quality attributes, as a function of storage time, indicated that they were first order processes. The rate constants were affected by package type and fat content. The effect of storage temperature on rate constants was slight.