The Acid Test: HPP and Lactic Acid For Raw Food Safety

Course overview

Considering the health risks associated with raw meat pet foods to pets and humans, High Pressure Processing (HPP) has shown promise in significantly reducing pathogens like Salmonella, E. coli STEC, and L. monocytogenes refrigeration. Since L. monocytogenes is more resistant to HPP, further formulation and process optimization are needed to ensure long-term safety. Chicken based raw diet pet food was inoculated with 7-8 log CFU/g cocktails of Salmonella spp., E. coli STEC or L. monocytogenes and stored at 4*C for 24 hours before the addition of either 0.7% or 1.0% w/v lactic acid fermentate (LAF) and HPP treated at 586 MPa for 2, 3 and 4 min after 24 or 72 hours storage at 4*C. HPP treated products were stored frozen up to 21 days and analyzed microbiologically. This study clearly demonstrates that when both LAF and HPP are employed, a full 5-log reduction of Salmonella spp., E. coli STEC, and L. monocytogenes is consistently achieved. The use of LAF appears to be instrumental in enhancing the lethality of the treatment. Qualitative enrichment further highlights that LAF not only boosts the immediate log reduction but also contributes to a more comprehensive inactivation profile during post-HPP frozen storage. The optimal combination in this study was found to be 1% LAF with HPP at 586 MPa for 4 minutes. The combo hurdles not only maximize pathogen inactivation but also provide both formulation and processing controls, serving as a robust strategy against potential re-growth during storage.