Question

The time required to kill microorganisms at a given lethal temperature is called ________. 
 

• A. Thermal Inactivation Time
• B. Thermal Death Time
• C. Thermal Critical Time
• D. Lag phase

Hint:

Remember the distinction: - Thermal Death Time (TDT) $\rightarrow$ calculates the Time required at a fixed temperature.
- Thermal Death Point (TDP) $\rightarrow$ calculates the lowest Temperature required for a fixed time.

Answer 1

The Correct Option is B

Step 1: Understanding the Concept:
Thermal death kinetics describe how microorganisms respond to heat over time.
These values are used to design safe thermal sterilization and pasteurization processes.
Detailed Explanation:
Let us review the definitions of thermal death parameters:
- Thermal Death Time (TDT) (2): The shortest time required to completely destroy a specific population of microorganisms in a food sample at a constant, specified lethal temperature.
- Decimal Reduction Time ($D$-value): The time required at a specific temperature to cause a $90\%$ (one log) reduction in the microbial population.
- Thermal Death Point (TDP): The lowest temperature at which all microorganisms in a liquid suspension are killed in a specified time (usually $10\text{ minutes}$).
- Lag phase (4): The initial period of bacterial growth where cells adapt to their environment but do not divide.

Step 2: Final Answer:
The time required to kill a population of microorganisms at a given lethal temperature is called the Thermal Death Time.