Inactivation of parasite transmission stages: efficacy of treatments on food of animal origin

Abstract

One third of parasitic outbreaks with known source in the US are attributable to food of animal origin (FoAO). Among 24 foodborne parasites ranked by FAO/WHO, 14 are associated with FoAO. Management of these biological hazards is essential to ensure food safety. This constitutes the first systematic review of control measures to inactivate foodborne parasites, including cooking, freezing, curing and combined processes, as well as high-pressure-treatment and irradiation. Wherever possible, the extent of foodborne parasite reduction (expressed as log units) and the methods of assessment of parasite inactivation are reported. Efficacy of freezing and heating depends on parasite species and developmental stage. Cooking at core temperature 60 – 75 °C for 15 – 30 min inactivates parasites in most matrices, but may not be enough to inactivate all parasites; for home cooking, USDA recommends heating meat at 62.8 - 73.9 °C core temperature. Freezing at -21 °C for 1 – 7 days inactivates parasites in meat or fish, but cannot be relied upon in home situations. Parasitic stages are sensitive to 2-5% NaCl, associated with higher osmotic stress, often augmented by lowering pH. Little is known about high pressure- and electron-beam irradiation; gamma radiation at >0.1-0.5 kGy is effective for fish parasites, except Anisakis (10 kGy); doses >0.4-6.5 kGy control meatborne parasites. Literature data are insufficient to model survival as response to treatment. Research on foodborne parasites should be improved towards standardization of experimental approaches for evaluation of inactivation techniques and methods to monitor inactivation.