Lipid oxidation is a degradation reaction of lipids, such as meats, protein meals, oil and fats. The process of lipid oxidation is fairly complex, and it is important to understand the many factors that can impact it and the potential consequences in a finished petfood diet.
Oxidation can have a significant effect on petfood quality; impacting color, nutrition, palatability, odor, taste, and shelf life. The most recognizable sign of lipid oxidation is altered odor and flavor. Odor resulting from oxidation is detectible by humans at very low (ppm) concentrations.
Pets are even more sensitive to aroma than humans, so their flavor thresholds are even lower. Figure 1 shows dogs’ sensitivity to aldehydes. In this case, pet food was top coated normally with a palatant and a fresh fat with very low levels of PV’s and aldehydes. Then the fat was spiked with 20, 40, and 80 ppm of a 50:50 mixture of hexanal and 2,4-decadienal. The following chart shows how these aldehyde spikes affected dogs’ choice in a palatability trial at a third-party kennel. Figure 1 shows lipid oxidation can have a large impact on a dog’s food choice.
Further complicating the challenges of oxidative stability and shelf life is the growth of natural, organic, and novel ingredients petfood trends. In response to these trends, petfood diets have seen an increased usage of unsaturated fats and oils. Unsaturated oils are more prone to lipid oxidation than saturated fats. For example, a diet high in fish and vegetable oil that uses brown rice instead of corn will have a fatty acid composition that is much more prone to oxidation than a traditional chicken, poultry fat and corn-based diet.
Trends such as raw, frozen, semi-moist, freeze-dried and high meat diets pose unique stability challenges and complexity. Many of these trends and ingredients require customized solutions. There is no one-size-fits-all antioxidant solution that works for all diet types.
It is important to partner with an antioxidant supplier who understands how to utilize antioxidants throughout the complex petfood supply chain and manufacturing process. At Kemin, we use our decades of experience to provide innovative solutions to renderers and petfood manufacturers, such as our NATUROX®, VERDILOX®, PARAMEGA™ product lines coupled with our suite of technical, laboratory, and application services.
1. Kemin Internal Document: SD-17-00022