Antioxidants in Dog Food

It is not uncommon now that many pet owners have become more aware of all the preservatives that are in their pet's food. On reading the label of your pet food it is preservatives that are referring to the use of antioxidants which are essential for the production of dry pet foods.

If these were not added oxygen would react with the oils, fats, pigments and fat soluble micronutrients therefore causing rapid deterioration of the food. This process is known as pre-oxidation or auto-oxidation and would result in off flavors, mal-odors, nutrient loss and color and lastly harmful by-products.

A lot can depend on the success of antioxidants because they can vary depending on which type and at what stage of the manufacturing process they are added. In general it would seem if they are added in the early stages of the production process the antioxidant becomes utilized this has a better effect for a longer shelf life.

All antioxidants go in the category of natural or synthetic, ethoxyguin; butylated hydroxyanisole and butylated hydroxytoluene are synthetic antioxidants. Most pet food manufacturers prefer these because of the low cost and their high effectiveness. As an example, 150 PPM of the synthetic ethoxyguin can be the equivalent of 1000 PPM of mixed tocopherols.

Manufacturers are under increased pressure from pet owners to use natural sources instead of using synthetic antioxidants. Pet owners are more aware today because of all the information or misinformation they can acquire by using the internet. There has been a five year study investigating the negative effect of ethoxyguin by the (American Association of Feed Control Officials) AAFCO, who want it lowered from 150 PPM to 75 PPM. No harmful effects were found from the study although it is pressure from the consumer for manufacturers to use natural antioxidants.

A large range of compounds like herbs, spices, plants, citric acid, vitamin c and a number of plant carotenoids and phenolic that control the oxidative process. Vitamin E is probably the most common of the naturally occurring antioxidants. Because there are eight different forms of vitamin E, they are normally mixed and act together. It is citric acid that assists in regenerating and stabilizing the effects of the antioxidant tocopherols.

There are some compounds that have been isolated from some herbs and spices that show commercial viable antioxidant activity. Rosemary, sage and thyme are some of the examples, rosemary extract contains eight different phenolic compounds like tocopherols that act together.

The use of natural antioxidants causes difficulty particularly with tocopherols because not only the high cost but their susceptibility to be broken down this leaves the antioxidant activity weaker in comparison to synthetic antioxidants. The latter would then shorten the shelf life of dry foods. Manufacturers have tried to manage the problem by the use of a complex variety of different antioxidants that have different properties that act with one another and still effective to limiting auto-oxidation process.

The use of natural antioxidants diminishes the shelf life for pet food, however for small animals that are on veterinary diets the impact has been less. This may be due to the fact that they are lower in fats and lower levels of unsaturated fatty acids than commercial dry pet foods. All dry pet foods need to have proper stock rotation ensuring that the best before dates are checked properly.