The Food Chemicals That Keep Mold and Bacteria Away
Benzoic acid holds off mold, while sodium nitrite holds off dangerous bacteria that can cause food poisoning.
Kurzgesagt – In a Nutshell · Processed Food Won’t Kill YouChemical names on a label can make shoppers put a package back. Benzoic acid and sodium nitrite sound alarming. In fact, some of them help keep food safe to eat.
Processed food means changed food, such as milk turned into yogurt or grain baked into bread. It becomes ultra-processed when makers add ingredients you would not keep in a home kitchen, such as artificial dyes or flavorings. The distinction matters because the unfamiliar names do not always mean unfamiliar danger.
Once food sits, it starts to change again. Mold spreads and bacteria multiply. Many preservatives added to food exist to interrupt that decay and to shield you from getting sick from contaminated food.
They divide the work. Benzoic acid, a common preservative, stops mold from taking hold. Sodium nitrite blocks the growth of certain harmful bacteria that can cause food poisoning. One guards against mold, the other guards against harmful bacteria.
It means a chemical alone does not make a food bad. Preservatives are on the ultra-processed list, but their job is to stop mold and block harmful bacteria before they reach you.
That does not mean these foods are free of downsides. Even when each additive or method seems harmless by itself, the combination can create foods that encourage overeating. Yet being processed is not the same as being poisonous.
Questions people ask
If preservatives prevent food poisoning, why do people worry about them?
The worry is mostly about long-term effects from eating large amounts of additives, not about immediate poisoning. Regulators in the United States and Europe set legal limits for preservatives like benzoates and nitrites, and review the science on cancer, allergies, and heart effects. Staying within those limits is considered safe for most people.
What is the difference between processed and ultra-processed food?
Processed food is any food that has been changed from its raw state, including yogurt, bread, cheese, and frozen vegetables. Ultra-processed food adds ingredients you would not normally use at home, such as synthetic colors, flavorings, emulsifiers, and preservatives. The second category is broader, and includes both sodas and some packaged whole-grain breads.
Does that mean I should prefer packaged food to fresh food?
Not necessarily. Fresh food can lose nutrients quickly, and frozen vegetables can retain vitamins longer, but both can be part of a healthy diet. The larger nutritional issue with ultra-processed food is that combinations of salt, sugar, fat, and flavorings can make it very easy to overeat. Safety from germs is only one part of healthy eating.