May 16, 2017

Fat Quality: What You Need to Know

By: Han Laumen

Pet food scientists know fat is an important ingredient in pet foods. However, not all fats are quality fats and even high-quality fats need to be treated to ensure they maintain that quality. That’s why it’s crucial for all disciplines within pet food producers—from purchasing and sales to marketing and general management—to understand how the investment in good fat quality contributes to pet food palatability and, ultimately, the bottom line.

As research and development director at AFB’s European headquarters in Oss, The Netherlands, it’s my job to understand the science behind palatability and to share technical insights for delivering palatability performance with customers and colleagues.


Fat that is not sufficiently stabilized will oxidize, which causes the fat to become rancid. Rancidity generates unpleasant off-notes that may impact a pet’s interest in the food—especially in cats. If the pet won’t eat the food, the pet parent is unlikely to purchase it again.

So how does a pet food company prevent oxidation and verify that prevention is working to help deliver the desired palatability? Here are some important tips:

  • Know your fat supplier. Governments do not regulate fat oxidation levels, so it’s up to you to ensure quality. Procure consistently good quality fats from a reputable source with whom you have an ongoing relationship.
  • Choose fats low in free fatty acids (FFAs). FFAs indicate a lack of freshness. If used as ingredients in foods, those foods can become rancid in a short time.
  • Have antioxidants added to fats at the supplier before delivery. Once fats begin oxidizing, it’s difficult to arrest the process—so stop it before it starts.
  • Protect fats through the production process. Adopt pet food packaging processes that replace oxygen with inert gas or use adequate antioxidants.
  • Monitor fats of raw materials and pet food products through the production process. At a regular frequency, measure both peroxide and hexanal. Don’t be fooled by a peroxide value that climbs early in oxidation, then falls again as the secondary oxidation process takes over. Measure the hexanal value as well, which shows a linear increase across time, for a true and complete picture of rancidity. (See Figure 1.)

For a true and complete picture of oxidation and potential rancidity, measure both peroxide and hexanal value.


For more detailed information on fats, including more methods for preventing oxidation and verifying stability, see “Fat Quality: Impact of Fats on Palatability” in the Downloads area at or email me at 

If you’re not sure what’s contributing to a palatability challenge, our experts can help you identify if it’s related to a fat or something else. To learn more about how AFB’s scientists and research and development capabilities can help achieve your palatability goals, connect with your local AFB representative.


Tags: , , , , , , , , , , , , , , , , ,

Download FREE White Paper