INTRODUCTION
It is common to add fat topically to extruded pet food. This provides a
source of added calories, essential fatty acids, flavor and texture for
the dog and cat. The fat also aids absorption of fat-soluble vitamins
(Bauer, 2006).
Most fats added to pet food are derived from animal sources as a
function of rendering. Rendering is an effective means for separating
the fat from animal tissue and does so through application of heat
(Romans et al., 2001). This thermal process is also effective in killing
pathogenic organisms. However, recent indications suggest that following
rendering the fat could be re-contaminated through handling, transport
and storage. Since fat is surface applied following the established kill
step (extrusion in pet food) this represents a potential vector for
reintroduction of pathogens onto the food.
Commonly found in poultry products, Salmonella remains a
significant economic and safety hazard in the food system (Batz et al.,
2012). Although the application of heat during the rendering process is
effective at inactivating most microorganisms, it does not provide
protection for post-rendering re-contamination (Cochrane et al., 2016;
Meeker, 2006). Recent work would suggest that acidulants such as lactic
acid, phosphoric acid, or sodium bisulfate may provide residual
preventive controls to pathogens introduced into fat (Dhakal et al.,
2019). However, no data exists as to how the addition of these
antimicrobial agents affect lipid oxidation or affect the shelf-life of
chicken fat. Therefore, it was our objective to determine the effect of
pathogen preventive acidulants at their previously established doses
(minimum inhibitory concentration) on measures of oxidation and shelf
life in treated poultry fat.