effect of heat, cold and aging time on the viability of encysted trichinella larvae

ABSTRACT

35 cuts of various sizes of heavily infected trichinous pork and whole carcass of a trichinous pig were used to study the effect of slow and quick freezing at -10°C, -20°C, -30°C, -35°C, 38°C and -40°C and the effect of dry and moist heat at 45, 50, 55°C on the viability of encysted larvae and aging as well. The results obtained indicated that the time required to kill the larvae in cuts of trichinous pork is such shorter in quick freezing than slow freezing. By slow freezing at -25°C the time required to kill the larvae in cuts weighing 5 kg was 108 hours, while by quick freezing was 48 hours. Experiments conducted on the effect of heat upon the encysted larvae proved that exposure of cuts weighing 2, 3.5 and 5 kg. to 55°C needs 15, 17, 18 hours respectively by using dry heat, while with moist heat, this time is respectively 40, 41, 48 minutes. As regards the effect of aging on encysted larvae, the present study shows that they were no longer alive in decomposed meat on day 56