what are food preservatives

Food preservatives are chemical substances that are added to food to help control and prevent the deterioration of food, providing protection against spoilage from microorganisms such as bacteria, yeast, and molds, and life-threatening botulism and other organisms that can cause food poisoning. They are used to slow down the decomposition and rancidification process, making food more resistant to microorganism growth and slowing the oxidation of fats. Preservatives can be either extracted from natural sources or synthetically produced. They can be antimicrobial, which inhibits the growth of bacteria or fungi, or antioxidant, which inhibits the oxidation of food constituents. Some common examples of preservatives include salt, sugar, vinegar, citrus juice, sodium benzoate, calcium propionate, potassium sorbate, tocopherols (Vitamin E), butylated hydroxyanisole (BHA), butylated hydroxytoluene (BHT), and ethanol. Preservatives protect the quality of foods and beverages, reduce food cost, improve convenience, lengthen shelf-life, and reduce food waste. Although Health Canada approves all of the preservatives that are used in Canada, many Canadians want to find ways to eat fewer preservatives and have begun buying more organic and unprocessed foods.