Final answer:
A food would qualify as TCS/PHF due to high moisture content, enabling rapid bacterial growth at temperatures ideal for bacteria, which is why temperature control is vital for food safety.
Step-by-step explanation:
Foods that require time and temperature controls for safety are typically high in moisture because moisture is a necessary component for bacterial growth. Such foods can become unsafe if they are not maintained at the correct temperatures, specifically between 4°C and 60°C (40 and 140°F), because these temperatures are ideal for bacterial proliferation. For example, foods with high water activity levels can support the growth of bacteria if not properly controlled, leading to the potential for foodborne illness. Jams and dried meats usually don't require refrigeration because they have low water activity due to high concentrations of salts or sugars, creating high osmotic pressure conditions that are not conducive to most microbial growth.
Applying heat can effectively control microbes; for example, boiling is a common method of killing vegetative cells and some viruses. However, more resilient microorganisms, such as endospores, can survive significant boiling times, making sterilization through boiling ineffective for certain types of microbial control. It is essential to understand and implement proper temperature control when handling TCS foods to maintain food safety and reduce the risk of foodborne diseases.