User manual MKA 120
Conforms to
Issue 07.07.2021_01 Page 13
Be aware
No pre-set step time:
If you have not entered a step time, time will be counted forward while the step is running. (
in
this way you always know how long the step has been in operation).
A maximum value of "99:59" (hours : minutes) can be displayed. If this value is exceeded,
only the colon between hours : minutes flashes.
5.6 Optional nominal values
A service technician can make further nominal values available by changing the configuration of
the controller. The relevance of these nominal values can vary, this is why your service
technician should explain them to you. The following description is just a list of possible
applications.
5.6.1 Delta temperature (Delta-T process)
Cooking with the Delta-T process (Delta temperature control) allows you to heat the product
gently and evenly. When using this process the chamber temperature is always kept higher, by
the nominal Delta value, than the actual core of the product. This means the temperature
difference between the surface and the core of the product always remains constant. The pre-set
nominal chamber value is used as upper limit value for chamber temperature control.
A lower nominal Delta value will prolong the duration of the cooking process and the heating
process is gentler, a higher nominal Delta value will speed up the cooking process.
Hint
Apart from a nominal temperature value and a nominal Delta value, you can also enter a
nominal core value, which will be used as core shut-down condition for the step.
5.6.2 FC
– value
Hint
Bacteria have to be killed through pasteurisation (FC70)/sterilisation(FC121). How thoroughly
the bacteria are killed depends on the temperature and the length of time this temperature is
maintained. A mathematical formula can be applied to this process. The degree to which the
bacteria are killed is called FC value.
The process:
It is the aim of
sterilisation
to kill
all the bacteria and their spores. How thoroughly the
bacteria are killed depends on the temperature and the length of time this temperature is
maintained. A mathematical formula can be applied to this process.
(
)
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Samplingra
F
Value
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mperature
eferencete
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ature
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10
The degree to which the bacteria are killed is called F-value.
For meat cans F-value 1 means the bacteria extermination which is achieved at a core
temperature of 121,1°C, when maintained for one minute. How thoroughly the bacteria are
killed also depends on the acidity of the conserved product. Acidic conserves, fruit juices,
pickled gherkins etc have a higher killing rate and therefore a different FC value table than
normal meat conserves with a PH value between 5 and 7.
