Reason for Blanching Fruits and vegetables

Reason for Blanching Fruits and vegetables.

Blanching is a pretreatment given to fruits and vegetables prior to freezing, drying or canning. This involves immersing fruits or vegetables in a water at temperature of 100°C or below for 1 to 3 mins. The heat treatment is followed by immediate cooling under  cold running water.

The essence of doing this, is to deactivate enzymes which are responsible for the loss of quality ( flavor, colour, texture, nutrients) of the product. Enzymes are proteins whose role  is to speed up chemical reactions and support life . But after harvest, they cause discoloration or browning reaction, off flavor, texture change and nutrients degradation.