No abstract

One-quarter pound (113g) ground beef patties containing 15 or 30% fat were packaged in either polyethylene bags or vacuum-packaged and stored at -12.2", -23.3", or -34.4"C for 20 weeks. At 4-wk intervals, samples were thawed and analyzed. The results were compared with fresh samples. Drip loss, cooking loss and shear strength increased with increasing time in frozen storage. Package type affected drip loss and cooking loss but not shear strength. Products with higher fat contents had higher drip loss, cooking loss, shear strength, and color (L, a, and b) values.

Oxidative rancidity in fresh and stored ground beef samples was measured using a thiobarbituric acid (TBA) assay with antioxidant protection. The independent variables were fat concentration (15 or 30%), package type (polyethylene or vacuum-packaged), freezer storage temperature (-12.2". -23.3" or -34.4"C) and storage time (4, 8, 12, -16, or 2d weeks j. At the end of each storage timesamples'were thawed and TBA values were determined on the samples before and after cooking. TBA values increased during the first 12 to 16 weeks after which time it decreased for both the cooked and uncooked samples. The higher fat samples, packaged in polyethylene, had higher TBA values for both cooked and uncooked patties. Uncooked patties stored at -12.2"C had higher TBA values than those stored at -23.3"C or -34.4"C but cooked sample TBA values showed no dependence on storage temperature.