Use of Preservatives in Food Preservation

 Use of Preservatives in Food Preservation

Preservative is a substance which we add to inhibit or stop the fermentation and acidic process or other decomposition. They usually act as antioxidants and interfere with enzyme activity and genetic mechanism. 

How to select preservative?

  • Preservative should-
  • Be economical
  • Should not cause any harm to human beings
  • Should stop grow of micro-organisms
  • Should not effect the original taste of food 
  • Should not cover inferiority of food

Classification of preservatives

We have heard about preservatives as class I and class II which includes,

Class I preservatives :

Sugar, vinegar, Honey, Dextrose, common salt, spices and consume.

Class II preservatives:

  • Benzoic acid and it's salt, sorbic acid and it's salt, sodium and potassium, propionate of sodium and calcium. 
  • Sugar binds the moisture and prevents growth of microorganisms. Sugar is used at a high concentration 65% or above. Example, jam and jellies are preserved with the use of sugar. 
  • Salt is used in high concentration around (15-20%). Salt is used in brine, curing solutions. It prevents water from being available for bacterial growth. 
  • Oil and spices on top of any food prevents growth of microorganisms like yeasts and molds. It prevents exposure to air. 
  • Vinegar or acetic acid inhibits growth of microorganisms as acidic inhibits growth of microbes. Citric acid is used in Preservation of certain fruits and vegetables. 
  • Propionate is used in cheese and baked foods to prevent growth of any moulds
  • Sodium benzoic acid is 200 times more soluble than acid. It is tasteless, odourless and more effective against yeasts and preservation action increase in the presence of carbon dioxide and acid media. In soft drinks 350 ppm of sulphur and 600 ppm of benzoic acid are permitted for Preservation but excess in juices can cause burning taste(0.1%) and may also darken the product. 
  • Sorbic acid have antimicrobial properties and in pure form it is white crystalline powder with acidic and agreeable taste. It's effectiveness increase in acid media. It is used in jam, fruits syrup, cheese, sweet pickles. 

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