Question

The main objectives of blanching are ________ 
(A) To retain the colour and flavour 
(B) To remove tissue gas 
(C) To reduce the size 
(D) To inactivate the enzymes 
Choose the correct answer from the options given below : 
 

• A. (A), (B) and (D) only.
• B. (B), (C) and (D) only.
• C. (A), (B), (C) and (D).
• D. (A), (C) and (D) only.

Hint:

The most important objective of blanching is enzyme inactivation (specifically peroxidase and catalase). Additionally, expelling intercellular gases prevents can corrosion and oxidation during storage.

Answer 1

The Correct Option is A

Step 1: Understanding the Concept:
Blanching is a mild thermal pre-treatment in which fruits or vegetables are exposed to boiling water or steam for a short time before canning, freezing, or drying.
Detailed Explanation:
The primary objectives of the blanching process are:
- To inactivate quality-degrading enzymes (D): Enzymes such as polyphenol oxidase, catalase, and peroxidase cause browning, off-odors, and nutrient loss during storage. Inactivating them extends shelf life.
- To retain color and flavor (A): Blanching sets the natural green color of chlorophyll and removes surface dust, helping to preserve fresh characteristics.
- To remove tissue gas (B): It expels air trapped within the plant tissues. This prevents can corrosion during canning and limits oxidation reactions during storage.
- It also softens the plant tissue, making it easier to pack tightly into containers, but it does not have "reducing size" (C) as a main objective.
Therefore, the primary objectives are (A), (B), and (D).

Step 2: Final Answer:
The main objectives of blanching are (A), (B), and (D), corresponding to option (1).