Question

Which of the following statements is true regarding drying and dehydration of fruits and vegetables?
(A). Freeze drying is not covered under the methods of preservation of fruits and vegetables by drying or dehydration.
(B). Microorganisms and enzymes need water in order to be active.
(C). Dried, dessicated or low moisture foods are the traditional dried foods
(D). Intermediate moisture or IM foods contain between 15% to 50% moisture.
Choose the correct answer from the options given below:

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

Hint:

The key to preservation by drying isn't just removing moisture, but reducing 'water activity' (a_w), which is the available water for biological reactions. This is the scientific principle that makes drying effective.

Answer 1

The Correct Option is D

Step 1: Core Idea: 
The task is to identify correct statements regarding food preservation via drying and dehydration. The central concept involves water removal to prevent food spoilage. 
 

Step 2: Statement Analysis: 
Let's examine each statement: 
\[\begin{array}{rl} \bullet & \text{(A): Incorrect. Freeze drying (lyophilization) is a dehydration method using sublimation (solid to gas). It's a drying technique. } \\ \bullet & \text{(B): Correct. Drying preserves food by lowering its water activity (aw). At low water activity, microbial growth and enzymatic reactions are inhibited. } \\ \bullet & \text{(C): Correct. Traditional sun drying creates low-moisture foods (e.g., raisins, dried fish), often called dried or desiccated foods. } \\ \bullet & \text{(D): Correct. Intermediate Moisture (IM) foods, like jams, jellies, and some dried fruits, have 15-50% moisture content. They are shelf-stable due to reduced water activity and factors such as high sugar levels. } \\ \end{array}\] 

Therefore, statements (B), (C), and (D) are accurate. 
 

Step 3: Conclusion: 
The correct answer includes statements (B), (C), and (D).