Thermal Inactivation of Feline Calicivirus in Pet Food Processing

Area of Science:

• Food Science
• Veterinary Virology
• Animal Nutrition

Background:

• Extrusion is a key process for manufacturing heat-treated pet food for domestic and international markets.
• Disease outbreaks impacting international trade necessitate research into virus inactivation in pet food.
• Limited data exists on virus inactivation within complex food matrices during extrusion processing.

Purpose of the Study:

• To investigate the efficacy of heat-treated extruded pet food in inactivating virus surrogates.
• To determine the impact of extrusion processing parameters on virus inactivation in a pet food matrix.
• To assess virus survival under conditions relevant to pet food production.

Main Methods:

• Utilized feline calicivirus (FCV) vaccine strain F-9 as a surrogate RNA virus.
• Conducted small-scale heat inactivation experiments using pet food raw materials.
• Performed small-scale pressure studies simulating extrusion conditions (1.6 MPa).
• Evaluated FCV-F9 survival under acidic palatant production conditions.

Main Results:

• Achieved a > 4 log10 reduction in FCV-F9 infectivity at 70 °C, below the minimum extrusion temperature of 100 °C.
• Extrusion pressure (1.6 MPa) showed no significant impact on FCV-F9 inactivation.
• FCV-F9 did not survive the acidic conditions used in producing animal-derived palatants.

Conclusions:

• Heat treatment during pet food extrusion significantly inactivates surrogate viruses like FCV-F9.
• The extrusion process, particularly heat, is effective in ensuring virus safety in dry pet food.
• Acidic conditions used for palatants also contribute to pathogen reduction in pet food manufacturing.