Food Preservatives

Food Preservatives

Introduction

• 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
    process.
  • 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.

Classification:

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.

2. 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.