Factors Affecting Premature Browning During Cooking of Store-purchased Ground Beef

Storage conditions, patty location within packages, and purchase time effects on premature browning (PMB) of ground beef during cooking to 55 °C were determined. Packages were purchased twice daily. Patties were formed soon after purchase or after overnight storage (4 °C). Patties from the outer portion of the packages purchased in the morning were bright red and had the highest incidence of PMB (62.5%) when cooked. Patties from inner portions of packages purchased in the afternoon and refrigerated overnight were more (P < 0.05) purple and had the lowest incidence (25%) of PMB. Premature browning incidence averaged 47%. Consumer handling procedures affected PMB apparently by changing the state of myoglobin in the packages.