Food Preservatives

Food Preservatives


  • Food preservatives are natural or synthetic chemicals that are added to foods or pharmaceuticals to retard spoilage, whether from microbial growth, or undesirable chemical changes.
  • Some methods of food preservation involve the use of salt, sugar or
    vinegar, which is sometimes considered to be foods rather than additives.
  • Some people believe preservatives are harmful.
  • Food preservatives have been around since centuries ago, as in pickled onions, salted meat and fish, sweetened fruit and spiced foods.
  • As people move away from the countryside and demand for food increased many people rely on processed items as part of their daily sustenance.
  • Food preservatives help maintain the freshness and shelf life of such food products because, without them, they would spoil quickly due to exposure to air, moisture, bacteria, or mold.
  • Either natural or synthetic substances may be added to avoid or delay these problems.

History of preservatives

  • Preservatives have been used since prehistoric times.
  • Smoked meat, for example, has phenols and other chemicals that retard spoilage.
  • The preservation of foods has evolved greatly over the centuries and has been instrumental in increasing food security.
  • The use of preservatives other than traditional oils, salts, etc. in food began in the late 19th century but was not widespread until the 20th century.

Importance of preservatives

  • Food preservatives are essential for many reasons. They are used to:
    • o Maintain consistency and texture of foods
      o Improve or retain nutritional properties
      o Delay spoilage
      o Enhance flavors, textures, and color
  • Maintaining consistency and texture of foods
    • It helps to sustain smoothness or prevent the food from separating, caking or clumping.
    • Preservatives slow product spoilage caused by mold, air, bacteria, fungi or yeast.
    • In addition to maintaining the quality of the food, they help control contamination that can cause foodborne illness, including life-threatening botulism.
    • One group of preservatives — antioxidants – prevents fats and oils and the foods containing them from becoming rancid or developing an off-flavor.
    • They also prevent cut fresh fruits such as apples from turning brown when exposed to air.
  • Improve or retaining nutritional properties
    • Enrichment replaces nutrients lost in processing — this occurs with grains, as some vitamins and minerals are lost in the milling
    • Fortification adds a nutrient that wasn’t there before and may be lacking in many people’s diets.
    • Iodized salt is an example.
    • This has proven useful in preventing goiter, a thyroid disease caused by a deficiency in iodine.
  • Delaying spoilage
    • Preservation usually involves preventing the growth of bacteria, fungi (such as yeasts), and other microorganisms, as well as retarding the oxidation of fats which cause rancidity.
  • Enhance flavors, textures, and color
    • Spices, natural and artificial flavors, and sweeteners are added to enhance the taste of food.
    • Food colors maintain or improve appearance.
    • Emulsifiers, stabilizers, and thickeners give foods the texture and consistency consumers expect.
    • Leavening agents allow baked goods to rise during baking.
    • Some preservatives help control the acidity and alkalinity of foods, while other ingredients help maintain the taste and appeal of foods with reduced fat content.


  1. Natural or class I preservatives:

In this category of natural food preservatives comes the salt, sugar, alcohol, vinegar, spices, syrup, edible oil and honey.

  1. Chemical or Class II preservatives:

In this category, chemical preservatives are included like sorbates, nitrites, benzoates, sulfites, nitrates of sodium or potassium, glycerides, glutamates and so on.