Raising your antioxidants game

A rising risk

The development of better pet food diets with an optimum balance of omega-3 and omega-6 fatty acids and content of long chain polyunsaturated fatty acids (such as EPA and DHA from algae or marine origin) has been a significant nutritional improvement for our pets. Being high margin products, these formulations are a major opportunity for pet food manufacturers and brand owners, but one that comes with increased risk: that of maintaining stability.

The risks associated with the formation of free radicals include rancidity development and the subsequent deterioration of product quality, pets’ refusals to eat products, and consumer complaints and exposure on social media platforms. 

Understanding of the high susceptibility towards oxidation and how to minimise it therefore remains a top priority for manufacturers and brands.

Antioxidant types today

Historically, antioxidants have been used in pet food systems to protect against lipid oxidation, maintain palatability and protect essential fatty acids and nutrients throughout the shelf life. The design of efficient synthetic antioxidants goes back to the 1940s. 

Today, antioxidants are used at many steps in the supply chain to protect quality of materials for animal nutrition: raw materials during rendering processes, bulk oils and fats, pre-mixtures, protein meals, palatants, extruded and oil-coated feed and pet food systems. This also applies to raw pet food stored in frozen form, freeze-dried pet food, dehydrated pet food as well as pet treats, which can oxidise too.

As fats remain an essential part of the diet, antioxidants will continue to play an important role in protecting these lipids against oxidation and rancidity. However, the type of antioxidants used in pet food diets has changed over the years. 

Recently, we have seen the suspension and likely banning of ethoxyquin in the EU. Ethoxyquin is now being replaced by safer synthetic antioxidants and even combinatory solutions of natural and synthetic antioxidants to achieve an equivalent shelf life extension to ethoxyquin.

Natural, clean and safe

Looking ahead, rising demand among millennials for healthy, nutritious and natural products will greatly impact the pet food market and the antioxidants that manufacturers are likely to prefer. So, which antioxidants have a natural, clean or safe profile? 

Natural mixed tocopherols (Vitamin E) have a good image and are obviously very important, because animal fats and oils contain only a trace amount of tocopherols, if any. A certain shelf-life extension can be achieved with natural mixed tocopherols; however, there is a limit. 

Rosemary extract (carnosic acid) will have an in-creasing importance and will further add to shelf-life beyond what natural mixed tocopherols can provide. A certain degree of purification is needed including selecting material, which will not impact the palatability. 

Ascorbyl palmitate, now widely used in infant formula, has a very safe profile. It is physiologically acceptable. It breaks down in the digestive tract and releases vitamin C and palmitic acid. It has been overlooked for pet food applications, but is now gaining more interest. Ascorbyl palmitate is an excellent antioxidant for rendered fats and oils and for dry pet food products.