Question

Which of the following is the low cost method of long term preservation of fruits and vegetables?

• A. Pasteurization
• B. Blanching
• C. Canning
• D. Exclusion of moisture

Hint:

While drying is highly cost-effective, it can cause changes in the food's physical structure (shrinkage) and loss of volatile aroma compounds compared to advanced, highly expensive methods like freeze-drying.

Answer 1

The Correct Option is D

Step 1: Understanding the Concept:
Food preservation technologies require capital investments and energy inputs.
Evaluating their cost-effectiveness is vital for establishing sustainable post-harvest preservation chains.

Step 2: Detailed Explanation:
- Exclusion of moisture (dehydration/drying): This is the oldest, simplest, and most economical long-term preservation method for fruits and vegetables.
- By removing water (lowering water activity below \(0.60\)), all microbial growth and enzymatic activities are completely arrested.
- Solar drying or simple hot-air drying requires minimal energy costs.
- Furthermore, dried foods have significantly reduced weight and volume, drastically lowering packaging, transport, and warehousing storage costs without requiring refrigeration.
- Canning requires expensive tin cans, high-pressure retorting energy, and heavy transport costs. Pasteurization and blanching are only short-term pre-treatments and do not provide long-term shelf-stability on their own.

Step 3: Final Answer:
The low-cost long-term method is the exclusion of moisture, which corresponds to option (D).