Effect of a dry acidulant coating on the palatability of dry extruded dog food

Abstract

In the pet food industry, Salmonella is getting greater scrutiny because it is considered a “reasonably foreseeable hazard” with the implementation of the Food Safety Modernization Act. Specifically, there is zero tolerance for any serotype of Salmonella in pet foods. Salmonella contamination was responsible for 78% of the Class I recalls in pet food according to the most recent Reportable Food Registry Report (FDA, 2015). One potential method of Salmonella mitigation shown to be effective was through coating the exterior of the kibble with a powdered dry acidulant, such as sodium bisulfate (SBS; Jones-Hamilton, Co.). Sodium bisulfate coating on both dog and cat kibbles was shown to provide complete mitigation of Salmonella within 14-d storage (Jeffrey et al., 2014). However, it is thought that the use of dry acidulant with a palatant for coating kibble may negatively impact palatability of a dry dog food. Therefore, the objective of this experiment was to determine if the use of a dry acidulant, SBS, would influence the palatability of a dry dog food. A single dry extruded all life stages dog food was collected from a commercial pet food manufacturer before the coating step. The kibble was coated with either 2.2% spray dried chicken liver + 0.2% SBS or 2.2% spray dried chicken liver + 0.2% powdered silica (control). A total of 20 beagles were used in a standard 2-bowl forced choice palatability test method for 2 d. Dogs were fed 400 g of both diets once per day, with bowls rotated daily to address side bias. Results were analyzed using the GLIMMIX procedure of SAS (Cary, NC). The inclusion of SBS did not affect daily preference of diet (P = 0.23). Furthermore, there was no effect of day (P = 0.18) or the interaction of treatment × day (P = 0.98). These results demonstrate that palatability is not affected by the inclusion of SBS with a palatant in the coating of dog food kibble. Considering that the inclusion of SBS has been shown to be effective at mitigating Salmonella in pet food and no negative effects on palatability were observed, the use of a dry acidulant in a dog food coating gives the industry a promising method to control Salmonella contamination of finished dog foods.