SALT AND AGING TIME EFFECTS ON VIABILITY OF TRICHINELLA-SPIRALIS IN HEAVY DRY-CURED HAMS AND SHOULDERS

SUMMARY: 28 pigs weighing approximately 100 lb were dosed with 10,000 to 15,000 excysted trichina larvae, grown to 285 lb and sacrificed. Fresh lean samples from one ham and shoulder per carcass were digested in a pepsine‐HCI solution and microscopically examined to determine infection rates. 24 of the more heavily infected hams and shoulders then were selected for further observations. The hams and shoulders were dry‐cured for 2 days per lb, using an 8% cure applied in 3 equal applications at 5‐day intervals. The cure contained salt, sugar, potassium nitrate and sodium nitrite. After curing, the meat was placed in salt equalization for 30 days, smoked for 24 hr at 100°F and aged at 75°F until termination of the study. Cored lean samples were taken from 8 hams and shoulders at weekly intervals after salt equalization and analyzed for salt concentrations and viability. Viable trichinae persisted throughout curing, salt equalization, smoking and 2 weeks of aging. Samples taken from hams and shoulders after 3 weeks of aging were found to be free of any live trichinae. Similar lean samples were taken at this time and force fed to rats for 5 days. After 8 weeks on a commercial ration the rats were sacrificed, artificially digested and examined. No trichina larvae could be recovered. Copyright © 1969, Wiley Blackwell. All rights reserved