We measured the incidence of premature
browning during cooking in ground beef that
was purchased from retail supermarkets and
prepared using common household procedures.
Patties made from meat on the outer portion of
the packages purchased in the morning had the
highest incidence of premature browning
(62.5%). Patties from inner portions of packages
purchased in the afternoon, refrigerated,
and prepared the next morning were more
(P<0.05) purple and had the lowest incidence
(25%) of premature browning. Overall incidence
of premature browning averaged 47%.
Because internal cooked color of ground beef is
such an unreliable indicator of doneness, temperature
measurements should be used to verify
that safe endpoint temperatures have been
reached.