Which of the following is the easiest way to recognize food contaminated with spoilage bacteria?

• A. Measuring the pH of the food
• B. Testing for the presence of bacterial DNA using PCR
• C. Visible changes in appearance, such as discoloration or mold growth
• D. Microscopic examination for bacterial cells

Answer: (C)

Verified step by step guidance

1. Understand that spoilage bacteria cause visible changes in food as they grow and metabolize, producing byproducts that alter the food's appearance, texture, and sometimes smell.
2. Recognize that measuring pH can indicate acidity changes but is not the most direct or easiest method to detect spoilage because pH changes might be subtle or delayed.
3. Know that testing for bacterial DNA using PCR is a sensitive and specific method but requires specialized equipment and expertise, making it less practical for quick spoilage detection.
4. Microscopic examination can reveal bacterial cells but requires a microscope and skill to interpret, and it may not distinguish spoilage bacteria from harmless ones easily.
5. Conclude that the easiest and most practical way to recognize food contaminated with spoilage bacteria is by observing visible changes such as discoloration, mold growth, or texture changes, which are direct indicators of spoilage.