What should never be done with old food products?

The correct response addresses the critical issue of food safety. Combining old food products with new ones can pose significant health risks, as it may lead to the contamination of the new products. Old food might harbor bacteria, toxins, or other harmful substances that can multiply and cause foodborne illnesses. The practice of mixing can obscure the freshness of the new ingredients, making it difficult to determine which food is safe or unsafe to consume.

Ensuring that only safe, fresh food is being served or consumed is vital for health. Therefore, it is essential to discard old food rather than incorporate it with new ingredients to maintain safety standards and prevent food safety hazards.