Q. What do you mean by Blanching?
The enzymes in the food system can be separated into four groups relating to the changes in flavour, colour, texture and nutritive value.
The inactivation of these enzymes is dependent upon both the time and temperature of heat treatment during the process of blanching. Peroxidase is the most heat stable enzyme in plants and thus is taken as the "universal indicator" for checking the adequacy of blanching for fruits and vegetables.
Blanching of vegetables prior to freezing and dehydration has some advantages, as well as, disadvantages. The advantages include stabilization of texture, colour, flavour and nutritional quality; removal of intercellular gases, reduction in microbial load and shrinkage of vegetable matter which can aid in the achievement of required fill weight. The disadvantages include loss of colour, flavour and nutritive value. However, the disadvantages can be taken care of by optimizing the time and temperature required for blanching.