Guide to Food Preservatives

If you’re like most people, you probably have some sort of packaged or canned food in your kitchen pantry right now. Many of these foods have preservatives added to them, but what are these and why are they used?

What Do Preservatives Do? 

Preservatives are substances or chemicals added to certain packaged foods and beverages. They reduce the risk of food poisoning, maintain freshness and nutritional quality and increase shelf life.

They do this by preventing spoilage and deterioration of the food, such as preventing the growth of mold and color, smell or texture changes. These changes are usually a result of microbial growth, exposure to air, fermentation or other chemical changes in the food. 

Which Ingredients Are Preservatives? 

There are three basic types of food preservatives: antimicrobial preservatives, antioxidants and non-synthetic compounds. These are:

Antimicrobial preservatives prevent microorganisms from growing on food. They include:

• sorbic acid and sorbates, often found in cheese, wine and baked foods
• nitrates and nitrites, used in meats and processed meat products
• sulfur dioxide and sulfites, common in wine and fruits
• sodium propionate, used for baked foods
• benzoic acid, found in acidic foods like salad dressing, pickles and jams

Antioxidants prevent oxidation from spoiling higher-fat foods like chips, cheese and oils. They include:

• ascorbic acid (Vitamin C)
• gallic acid
• tocopherols

Non-synthetic compounds prevent fruits and vegetables from being damaged by enzymes. They include:

• citric and ascorbic acid
• rosemary and oregano extracts
• tocopherol
• vinegar
• salt
• alcohol
• castor oil
• diatomaceous earth

Are Preservatives Safe to Eat?

Food preservatives are regulated by the FDA and have been deemed Generally Recognized As Safe (GRAS). The FDA regularly updates the status of food preservatives used in the United States when any changes are made. You can find the current status of food additives in the FDA database. For instance, if a food additive has been determined to be toxic and unsafe, it is banned and labeled as such on the database.

That being said, there are some controversial food preservatives that are widely used today.

Sodium nitrite is often added to processed meat products to prevent botulism. It’s been shown to react with proteins during high heat cooking and form N-nitrosamines, which are likely harmful compounds. Some studies have also shown that consuming sodium nitrite may affect your body's overall health negatively. 

Sodium benzoate was used in the past to maintain freshness of canned tomato paste, but this can create the carcinogen benzene when it comes in contact with Vitamin C. Most manufacturers have moved away from using this preservative.

There are also some studies suggesting that sodium benzoate and other food additives may cause hyperactivity in children, but more research is needed.

Food preservatives are not all dangerous or toxic. Many are important for keeping our food supply fresh, nutritious and safe. Next time you’re grocery shopping, take a look at the ingredient label on any packaged foods to see what preservatives are used and determine whether you have any concerns.