Which risk remains after pasteurization?

• A. Post-pasteurization contamination and heat-resistant spores
• B. All viruses survive
• C. No risks at all
• D. Only non-pathogenic bacteria remain

Answer: (A)

Pasteurization greatly reduces dangerous microbes but doesn’t make milk completely risk-free. The main risk that remains is twofold: contamination after the heat treatment (post-pasteurization contamination) and the survival of heat-resistant spores.

After pasteurization, milk can be contaminated by contact with dirty equipment, packaging materials, or surfaces, or by handling in unsanitary conditions. If the product is then stored or transported under improper temperatures or times, these contaminants can multiply and cause spoilage or illness.

In addition, some bacteria form spores that can withstand pasteurization temperatures. These spores can survive the heat treatment and, if stored in favorable conditions, germinate into active bacteria later, leading to spoilage or potential health risks.

So the remaining risk is not that all viruses survive, nor that there are no risks at all, and it isn’t that only non-pathogenic bacteria stay. The key remaining concerns are post-pasteurization contamination and heat-resistant spores.