High hydrostatic pressure activity on the disinfection of clams artificially contaminated with feline calicivirus.

Background: The contamination of shellfish with gastroenteric viruses may cause outbreaks because they are often eaten raw or under-cooked. High-hydrostatic pressure treatments have already proven to be effective in reducing high viral load in shellfish samples. The objectives are the assessment of the viral load reduction of contaminated clams using HHP treatments at different pressures and times and the study of the changes caused by these treatments in some food physical parameters.

Methods: Clams were contaminated with a solution containing Feline Calicivirus; they were closed in envelopes and treated with 300, 400, 500, 600 MPa for 1, 3, 5, 7 min for every pressure value. After the treatment the residual viral titre was calculated. The texture parameters were obtained after treating clams samples at the same pressure values but only for 3 and 7 min and analysing them with a TPA test.

Results: HHP treatments of 500 and 600 MPa were sufficient to cause a total inactivation at every timelength considered while with 300 and 400 MPa after 1 min, concentrations of 1.13 and 0.55 respectively were found. In general hardness and gumminess tend to increase after the treatment whereas springiness and cohesiveness decrease a bit.

Conclusions: HHP treatments showed good sterilization ability against FCV but it's necessary to consider that FCV has a lower resistance to disinfection than Human norovirus. Texture changes are in line with what is reported in literature.