Spoilage and Petfood Palatability

Study: Direct Application of Biogenic Amines to Kibble¹

Biogenic amines (BA) are byproducts of microbial spoilage that are produced by decarboxylation of free amino acids.  The concentrations of some biogenic amines (tyramine, putrescine, and cadaverine) normally increase during the processing and storage of meat and meat products, whereas others (spermidine and spermine) decrease or remain constant.²  The freshness and quality of meat and meat products is therefore critical for the quality and, and potentially palatability, of the final petfood products.

Even if the presence of biogenic amines in pet food could affect palatability, no data was available at the beginning of this study to fully evaluate this topic.  The objective of this study was to determine the dosage of biogenic amines able to affect palatability in cats as well as in dogs, by treating selected standard diets with controlled amounts of biogenic amines of choice, respectively histamine, putrescine and cadaverine.

Palatability of treated cat food showed a negative impact for kibbles containing 300 ppm of putrescine, but the biogenic amine mixture didn’t show the same effect as the amine alone, see Figure 1.  Further tests would be needed to determine the minimum threshold for negative palatability impact.  Monitoring the level of putrescine in cat products could be a way to improve palatant efficacy and could lead to better performing products.

Figure 1. Palatability performance of cat kibbles coated with solutions of biogenic amines.

(NS: p > 0.05; *: 0.01 < p ≤ 0.05; **: 0.001 < p ≤ 0.01; ***: p ≤ 0.001)

Study: Effects of Preservation of Palatant Starting Material on Palatability³

Production of high quality pet food requires the use of good quality raw materials. The quality of common petfood raw materials, including animal protein meal and fresh or frozen meat or meat byproducts, depends of the freshness of the raw materials before processing and good preservation after processing. Unfortunately, in practical conditions it is very difficult to use fresh raw materials only in a processing plant.

The objective of this study was to evaluate the effect of preservation of poultry viscera on microbiological counts and on the palatability of a palatant made from poultry viscera with different preservative treatment times. 

In order to evaluate the influence of poultry viscera treatments on palatant performance, ten palatants were created using the same formula, with the only variable being the treatment of the poultry viscera starting material.  The ten palatant variations are listed in Table 1, grouped by variables that were tested head-to-head in palatability trials.

Palatability trials show that immediate treatment of viscera has a significant impact of palatability when palatants were prepared 24 to 48 hours after treatment.  It is shown that the palatability effect of the addition of a preservative is limited when the viscera quality has already started to deteriorate.  

Viscera Treatment Trials