Food Microbiology
D-value
The time at a given temperature required to destroy 90% of a microbial population — one log reduction.
Used by canneries and sterilisation engineers to work out exactly how long a product must be heated to kill enough bacteria to be safe.
Related terms
z-value
Food MicrobiologyThe temperature increase required to reduce the D-value by a factor of ten — the slope of the thermal death time curve.
F-value
Food MicrobiologyThe total lethality of a heat process expressed as equivalent minutes at a reference temperature. F0 is the reference at 121.1 °C with z = 10 °C.
12D concept
Food MicrobiologyThe commercial sterility standard for low-acid canned food: a heat process delivering twelve decimal reductions of Clostridium botulinum spores.
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