Antioxidants

This is another very important group of food preservatives whose function, in a nutshell, is to keep fats from turning rancid. The purpose of antioxidant food additives, just like antioxidant nutritional supplements, is to take up bonding sites on molecules so random “free radical” atoms can’t attach and form other sorts of undesirable compounds. For a full explanation that includes a parable about preschool teachers, toddlers and disruptive teenagers, check out this old post on shortening and oil. Common antioxidants include ascorbic acid (vitamin C), an isomer of vitamin C called erythorbic acid, butylated hydroxyanisole (BHA) and, of course, sulphur dioxide.