Question

The water activity of the food product at the end of constant drying rate is:

• A. \(\text{Less than 1}\)
• B. \(\text{Remains constant at 1}\)
• C. \(\text{Equals to zero}\)
• D. \(\text{Drops below 2}\)

Hint:

Water activity (\( a_w \)) decreases during drying, limiting microbial growth and extending shelf life.

Answer 1

The Correct Option is A

Step 1: Understanding water activity (\( a_w \)).
 - Water activity (\( a_w \)) refers to the amount of water available for microbial growth. 
- In fresh food, \( a_w \) is close to 1, but during drying, the water content decreases, leading to a reduction in \( a_w \). 
Step 2: Explanation of incorrect options. 
- Remains constant at 1 (B): This is incorrect because drying decreases water activity, and it doesn't stay at 1. 
- Equals to zero (C): While dried food may seem dry, it still retains a small amount of water, so \( a_w \) does not reach 0. 
- Drops below 2 (D): Water activity values range from 0 to 1, so it cannot drop below 2. 
Step 3: Selecting the correct option. The correct answer is (A) Less than 1 since water activity decreases during drying.