Subtopic: Kinetics of microbial death – pasteurization and sterilization of milk and other liquid foods
Question Statement:
A canned liquid food containing $10^5$ spores of \textit{Clostridium botulinum} per can undergoes thermal sterilization at $121.1^\circ\text{C}$. The decimal reduction time ($D_{121.1}$) is $0.25\text{ minutes}$. To ensure a $12\text{D}$ cook reduction, the required holding time at $121.1^\circ\text{C}$ is ________ minutes (answer in integer).
Answer Key:
3
Step-by-Step Solution & Explanation
The $12\text{D}$ concept requires a $12$-log cycle reduction in viable spore population:
$F_0 = 12 \times D_{121.1}$
Given $D_{121.1} = 0.25\text{ minutes}$:
$F_0 = 12 \times 0.25 = 3.0\text{ minutes}$
Thus, the holding time required at $121.1^\circ\text{C}$ is $3\text{ minutes}$.