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United States Department of Agriculture

Agricultural Research Service

Title: THE EFFECTS OF E-BEAM IRRADIATION AND MICROWAVE ENERGY ON EASTERN OYSTERS (CROSSOSTREA VIRGINICA) EXPERIMENTALLY INFECTED WITH CRYPTOSPORIDIUM PARVUM)

Author
item Collins, Marina
item Flick, George
item Smith, Stephen
item Fayer, Ronald
item Rudendall, Eric
item Lindsay, David

Submitted to: Journal of Eukaryotic Microbiology
Publication Type: Peer reviewed journal
Publication Acceptance Date: 8/15/2005
Publication Date: 12/1/2005
Citation: Collins, M.V., Flick, G.J., Smith, S.A., Fayer, R., Rudendall, E., Lindsay, D.S. 2005. The effects of e-beam irradiation and microwave energy on eastern oysters (Crossostrea virginica) experimentally infected with Cryptosporidium parvum. Journal of Eukaryotic Microbiology. 52(6):484-488.

Interpretive Summary: Shellfish such as oysters, clams and mussels have been identified as potential sources of infection for humans with the protozoan parasite Cryptosporidium. Inactivation of this parasite and other pathogens in uncooked shellfish would provide increased food safety for healthy and at-risk consumers. The present study tested the effects of two food processing treatments, e-beam energy and microwave energy, on oysters artificially infected with Cryptosporidium. After exposure to the processing treatments, oyster tissues were fed to neonatal mice. Significant reductions in infectivity were observed after e-beam treatment at doses of 1.0, 1.5 and 2.0 kilogray (kGy). At 2 kGy all infectivity was eliminated without affecting the appearance of oyster tissue. Microwave exposures for 1-3 seconds resulted in a reductions in infectivity that did not differ significantly from tissue that was untreated and treatment for 2 and 3 seconds unacceptably changed the color and texture of the oyster tissue. Therefore the e-beam treatment but not the microwave treatment appeared to have commercial potential as a food processing method.

Technical Abstract: Shellfish have been identified as a potential source of Cyptosporidium infection for humans. Inactivation of this parasite and other pathogens in raw molluscan shellfish would provide increased food safety for healthy and at-risk consumers. The present study examined two food processing treatments, e-beam energy and microwave energy, on infectivity of Cryptosporidium in artificially infected oysters. The processed tissues were fed to neonatal mice. Significant reductions in infectivity were observed after treatment with e-beam irradiation at doses of 1.0, 1.5 and 2.0 kGy. At 2 kGy all infectivity was eliminated without affecting the appearance of oyster tissue. Microwave exposures for 1-3 seconds resulted in a reductions in infectivity that did not differ significantly from untreated controls. Microwave treatment for 2 and 3 seconds unacceptably changed the color and texture of the oyster tissue.

Last Modified: 8/24/2016
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