Why are there preservatives in cat food? The short answer is so cat food has a longer shelf life.
Here’s the long answer: While oxygen is essential for cats to live, it is a “killer” of cat foods. When exposed to air, the unsaturated fat contained in dry and soft-moist cat foods undergoes oxidation–that is, the fat molecules chemically react with oxygen.
This process generates highly reactive chemicals known as free radicals, which promote or catalyze further fat oxidation. Manufacturers add fat preservatives to cat food as a means of delaying the onset and progression of fat oxidation in products.
Fat preservatives are chemicals with a greater affinity for free radicals produced during oxidation than unsaturated fat. As oxidation begins, these compounds scavenge the free radicals and convert them to harmless substances, such as water. Removing free radicals produced during the early stages of fat oxidation prevents their catalytic effect on further oxidation, greatly reducing the rate at which fats become rancid. This process extends a cat food’s shelf life.