Preservatives are natural or man-made chemicals that are added to food to prevent spoilage, improve appearance, and maintain the foods nutritional quality. They are used to increase the shelf life of food and protect against foodborne illnesses. Some common preservatives include:

• Salt: Salt is the best natural food preservation method which efficiently drops the growth of bacteria in food. For meat and fish preservation, salt is used as a natural food preservative. Other natural preservatives in the category are sugar, alcohol, and vinegar. These are used for preparing jams and pickles.

• Sugar: Sugar reduces the moisture content in food, which inhibits the growth of bacteria that spoil food. Jams, jellies, and squashes are preserved by sugar.

• Sodium benzoate: Sodium benzoate is a common preservative used in pickles, jams, and squashes to prevent spoilage.

• Sodium metabisulphite: Sodium metabisulphite is another common preservative used in pickles, jams, and squashes to prevent spoilage.

• Natamycin: Natamycin is a preservative that is widely used in the surface treatment of cheese and sausages. It can be naturally sourced from bacteria commonly present in soil.

• Sorbic acid and sorbate compounds: These are antimicrobial preservatives used in processed cheese, processed fruit and vegetables, bread and rolls, fine bakery wares, sauces, and potato products.

• Benzoic acid and benzoate: These are antimicrobial preservatives used in flavored fermented milk products, fruit, and more.

Preservatives can be extracted from natural sources or synthetically produced.