3. Food Microbiology and Safety

Microbial Testing — Quiz

Test your understanding of microbial testing with 5 practice questions.

Practice Questions

Question 1

In an \$n,c,m,M\$ sampling plan for microbial testing, what does the parameter \$m\$ represent?

Question 2

Given a sampling plan with \$n=5\$, \$c=1\$, \$m=100\ $\mathrm{cfu/g}$\$, and \$M=1000\ $\mathrm{cfu/g}$\$, how many samples may have counts between \$m\$ and \$M\$ inclusive for the lot to be accepted?

Question 3

Which culture-based detection method is most appropriate for identifying low levels of Listeria monocytogenes in a ready-to-eat food sample?

Question 4

Which rapid detection method quantifies microbial DNA in food samples using fluorescent probes during amplification?

Question 5

Three replicate samples yield counts of \$1.0\times10^4\$, \$1.2\times10^4\$, and \$0.8\times10^4\$ cfu/g. What are the mean count and relative standard deviation (RSD)? Show your calculation.