Potential of Irradiation Technology for Improved Shellfish Sanitation

Abstract

Ionizing radiation is shown capable of serving as an effective sanitizing treatment improving the sanitary quality of shellfish and providing an increased margin of safety for shellfish consumers. 60Co irradiation of the hard‐shelled clam, Mercenaria mercenaria, and the oyster, Crassostrea virginica, significantly reduced virus carriage numbers without unduly affecting shellfish survival rates or desirable organoleptic qualities. A D10 value of 2 kGy was determined for depletion of hepatitis A virus in clams and oysters as measured by in situ hybridization fluorescent foci and cytopathology enumeration methods. A D10 value of 2.4 kGy was determined for depletion of rotavirus SA11 in clams and oysters as measured by a plaque forming unit enumeration method. Study results showed ionizing radiation capable of providing an extra, highly effective safeguard of shellfish sanitary quality when combined with traditional depuration treatment. Data drawn from other studies is introduced which shows D10 values as low as 1.0 kGy effectively eliminate Vibrio cholerae, and V. parahemolyticus, from shellfish.

Quantifying the Reduction in Potential Health Risks by Determining the Sensitivity of Poliovirus Type 1 Chat Strain and Rotavirus SA-11 to Electron Beam Irradiation of Iceberg Lettuce and Spinach

“…There is a linear relationship between dose and level of virus inactivation. This linear relationship between virus inactivation and ionizing radiation has been reported earlier (2,26,35). Poliovirus exhibited greater resistance to E-beam irradiation than did rotavirus (Table 1).…”

Susceptibility of Murine Norovirus and Hepatitis A Virus to Electron Beam Irradiation in Oysters and Quantifying the Reduction in Potential Infection Risks

“…A D 10 value of 13.5 kGy was reported for F coliphages (12). Mallet et al (27), when employing gamma irradiation, reported no significant difference in the inactivation of viral pathogens, reporting D 10 values of 2.02, 3.1, and 2.4 kGy for HAV, poliovirus I, and rotavirus SA11, respectively. As stated earlier, we are not aware of any published studies on enteric viruses in whole oysters treated with E-beam irradiation.…”

“…Gamma radiation as a sanitization treatment for shellfish has been studied by different research groups (12,16,(25)(26)(27)(28). A variety of bacterial pathogens are susceptible to ionizing radiation, such as Vibrio cholerae, V. parahaemolyticus, and V. vulnificus, with D 10 values as low as 0.1 kGy (27,29). Inactivation studies on Salmonella spp.…”

Inactivation of a Human Norovirus Surrogate, Human Norovirus Virus-Like Particles, and Vesicular Stomatitis Virus by Gamma Irradiation

“…Based on our results, MNV-1 is much more resistant than FCV and CaCV to gamma irradiation. Irradiation of other food-borne and waterborne viruses, such as hepatitis A virus (HAV) (9), rotavirus (41), and poliovirus (27), has been reported. It was found that the D 10 values (dose required to reduce infectivity by 1 log 10 ) for HAV in lettuce and strawberries were 2.72 Ϯ 0.05 and 2.97 Ϯ 0.18 kGy, respectively (9), while the D 10 value for gamma irradiating HAV in clams and oysters was 2 kGy (41).…”