Calculated PNSU for Selected Pathogens at 80 °C/20 min & 100 °C/5 min*
Microorganism | D60—Pflug reported (min) | z-value Pflug reported (°C) | D80—estimated** (min) | D100—estimated** (min) | Assumed N0**** (cfu) | F = 20 Estimated PNSU @ 80 °C/20 min*** | F=5 Estimated PNSU @ 100 °C/5 min*** |
---|---|---|---|---|---|---|---|
Aeromonas hydrophilia | 0.066 | 6.0 | 0.00007 | 0.00000007 | 100 | 10−285,000 | 10−71,400,000 |
Campylobacter jejuni | 0.35 | 6.5 | 0.0004 | 0.0000004 | 100 | 10−50,000 | 10−12,500,000 |
Escherichia coli | 2.0 | 5.0 | 0.0002 | 0.00000002 | 100 | 10−100,000 | 10−250,000,000 |
Listeria monocytogenes | 16.7 | 6.5 | 0.02 | 0.00002 | 100 | 10−1000 | 10−50,000 |
Salmonella species | 2.5 | 5.6 | 0.003 | 0.000003 | 100 | 10−6600 | 10−1,666,000 |
Staphylococcus aureus | 3.0 | 9.5 | 0.03 | 0.0003 | 100 | 10−600 | 10−16,600 |
Vibrio species | 2.6 | 6.0 | 0.003 | 0.000003 | 100 | 10−6600 | 10−1,666,000 |
Yersinia enterocolitica | 5.0 | 5.0 | 0.0005 | 0.00000005 | 100 | 10−40,000 | 10−100,000,000 |
↵* D60 and z-value data in this table from Pflug (16).
↵** D80 and D100 values calculated from Pflug and rounded off for ease of calculation. Not precise, see note below.
↵*** PNSU values are rounded off for ease of comprehension.
↵**** N0 values have no meaningful impact on the estimated PNSU.
Note: Extrapolation of the D-value far from the reported 60 °C values introduces uncertainty; however, this lack of precision does not alter the recommendations of this paper for wider use of lower temperature moist heat sterilization processes.