Question

Treatment of fruits and vegetables with boiling water or steam for a short period followed by cooling prior to canning is:

• A. Blanching
• B. Sterilization
• C. Pasteurization
• D. Curing

Hint:

To check if blanching is successful, food scientists test for the presence of Peroxidase. If the enzyme is dead, the blanching was sufficient.

Answer 1

The Correct Option is A

Concept: Thermal processing is a fundamental tool in food preservation to ensure safety and quality.

• Blanching: A mild heat treatment (85–100°C).

• Purpose: Primarily to inactivate enzymes and expel intercellular gases.

• It is not a primary preservation method but a preparatory step.

Step 1: Understanding the mechanism.
Fruits and vegetables are exposed to hot water or steam for 1 to 10 minutes. This process is immediately followed by rapid cooling in cold water.

Step 2: The role of enzyme inactivation.
Naturally occurring enzymes like Peroxidase and Catalase cause browning and off-flavors. Blanching denatures these enzymes, stabilizing the product's color and texture.

Step 3: Preparation for canning.
The heat softens the tissue, allowing for easier packing into cans. It also removes air from the tissues, which prevents internal corrosion of the can. Final Answer: (A)