The USDA recommends that consumers of fresh pork cook
the product to an internal temperature of 77°C. Although
considerably higher than temperatures at which trichinae are
killed (60°C), this temperature allows for different methods of
cooking which do not always result in even distribution of
temperature throughout the meat.
No information is available on possible differential
susceptibility of the different species types of Trichinella to
heating.
Freezing
Thermal death curves have also been generated for the effect
of cold temperatures on the viability of T. spiralis in pork (28).
Based on the data, the predicted times required to kill
trichinae were 8 min at -20°C, 64 min at -15°C, and 4 days
at -10°C (Fig. 3). Trichinae were killed instantaneously at
-23.3°C. The USDA Code of Federal Regulations requires that
pork intended for use in processed products be frozen at
-17.8°C for 106 h, at -20.6°C for 82 h, at -23.3°C for 63 h,
at -26.1°C for 4 8 h, at -28.9°C for 35 h, at -31.7°C for 22 h,
at -34.5°C for 8 h or at -37.2°C for 0.5 h (47). These
extended times take into account the amount of time required
for temperature to equalise within the meat along with a