Step 1: Understanding the Concept:
In food thermal processing, specific mathematical values (\(D, z, F\) values) are used to quantify the thermal death kinetics of bacteria and calculate sterilizing processes.
Step 2: Detailed Explanation:
Let us define each of the thermal death kinetic terms:
1. \(D\)-value (Decimal Reduction Time DRT): The time in minutes at a specific constant temperature required to reduce the microbial population by \(90\%\) (or one log cycle). Thus, (C) and (D) are incorrect.
2. \(z\)-value: The temperature change in \(^{\circ}\text{C}\) or \(^{\circ}\text{F}\) required to change the \(D\)-value by a factor of 10. Thus, (B) is incorrect.
3. \(F\)-value (Sterilizing Value): The total time in minutes required to destroy a stated number of microorganisms or spores at a defined reference temperature.
The reference temperature is typically set at \(121^{\circ}\text{C}\) (or \(250^{\circ}\text{F}\)) for low-acid canned foods, and this specific value is denoted as \(F_0\):
\[ F_0 = D_{121} \times (\log N_0 - \log N_t) \]
where \(N_0\) is the initial microbial load and \(N_t\) is the final surviving population.
Therefore, the \(F\)-value represents the total integrated sterilizing value of a thermal process.
Step 3: Final Answer:
Therefore, the F value is defined as the number of minutes required to destroy a stated number of organisms at \(121^{\circ}\text{C}\).