Q. Show various methods of blanching for the vegetables?

To carry out various methods of blanching for the given vegetables.

• carry out various methods of blanching, and

• select the best method for further processing.

Principle

Blanching and cooling are necessary steps in the processing of vegetables. Blanching is a partial pre-cooking treatment in which vegetables/fruits are usually heated in water or in steam before processing. There are many ways of blanching, depending upon the type of vegetable and the products desired. The main purpose of blanching before processing is to inactivate enzymes, remove raw and bitter flavour, stabilize the colour, stabilize the texture, reduce bacterial load and add desirable additives.

Various methods are employed for blanching of vegetables such as hot water blanching, steam blanching, microwave blanching with water spray or air cooling or a combination of these.

Materials Required

Samples of vegetables to be blanched

Metallic Sieves

Microwave

Petri dishes

0.08% peroxide H2O2: Dilute 2.8 ml of 30% H2O2 with water and store in a dark bottle in a refrigerator. Prepare fresh every week

0.5% Guaiacol in 50% ethyl alcohol

Stop-watch

Thermometers

Beakers

Pestle and mortar

Test tubes