Question

The lowest water activity (\(a_w\)) supporting the growth of Staphylococcus aureus in food under aerobic condition is

• A. 0.98
• B. 0.91
• C. 0.89
• D. 0.86

Hint:

Water activity (\(a_w\)) is a critical factor for controlling microbial growth. For Staphylococcus aureus, the threshold is 0.86 under aerobic conditions.

Answer 1

The Correct Option is D

Step 1: Understanding water activity.
Water activity (\(a_w\)) is a measure of the available water in a food that supports microbial growth. Staphylococcus aureus is known to grow at low water activity, and the growth of this bacterium typically occurs at a \(a_w\) of around 0.86 under aerobic conditions.
Step 2: Analyzing the options.
- (A) Incorrect, 0.98 is above the threshold for microbial growth, and Staphylococcus aureus can grow at higher water activities.
- (B) Incorrect, while 0.91 is low, it is still above the value supporting growth in aerobic conditions.
- (C) Incorrect, 0.89 is still above the threshold.
- (D) Correct, 0.86 is the water activity below which Staphylococcus aureus can grow in aerobic conditions.
Step 3: Conclusion.
Thus, the correct answer is (D) 0.86.