Microwave inactivation of Cyclospora cayetanensis sporulation and viability of Cryptosporidium parvum oocysts.
The efficacy of microwave heating on the viability of Cryptosporidium parvum oocysts and on the sporulation of Cyclospora cayetanensis oocysts for various periods of cooking times (0, 10, 15, 20, 30, and 45 s) at 100% power was determined. Cyclospora oocysts were stored in 2.5% dichromate at 23 degrees C for 2 weeks, and sporulation rates were then determined. The 4',6-diamidino-2-phenylindole and propidium iodide vital stain and the neonate animal infectivity assay determined Cryptosporidium oocyst viability. Cryptosporidium oocysts could be completely inactivated with as little as 20 s of cooking time, whereas Cyclospora sporulation was observed up to 45 s. Two of the examined microwave ovens were more effective at reducing sporulation and viability than the third one. Because of the variability of temperature achieved by the various ovens, cooking time was not an accurate parameter for parasite inactivation. Cryptosporidium oocysts could be inactivated only when temperatures of 80 degrees C or higher were reached in the microwave ovens.
Ortega
Ynes R
YR
Center for Food Safety and Department of Food Science and Technology, University of Georgia, Griffin, Georgia 30223, USA. ortega@uga.edu
Liao
Jyeyin
J
D000818:Animals; D003257:Consumer Product Safety; D016785:Cryptosporidium parvum / Q000254:growth & development / Q000528:radiation effects*; D021744:Cyclospora / Q000254:growth & development / Q000528:radiation effects*; D004307:Dose-Response Relationship, Radiation; D005514:Food Irradiation; D016266:Food Parasitology; D005519:Food Preservation / Q000379:methods*; D006801:Humans; D008872:Microwaves; D033661:Oocysts / Q000254:growth & development; D013997:Time Factors