What is D-value and its significance?
In microbiology, in the context of a sterilization procedure, the D-value or decimal reduction time (or decimal reduction dose) is the time (or dose) required, at a given condition (e.g. temperature) or set of conditions, to achieve a log reduction, that is, to kill 90% (or 1 log) of relevant microorganisms.
What is the effect of Z value on F value?
The z value for spore death time typically ranges between 16 to 20 F. As shown in fig. 2, z = 18 F, and indicates that if a process is raised 18 F, the processing time can be lowered one log cycle (10 to 1 min. for this example) and still have an equivalent process.
What is the difference between D and Z values?
D value measures the time required to kill 90% of the population of a particular microorganism in a specific medium at a specific temperature. In contrast, Z value is the temperature change that is required to achieve a tenfold reduction in the D-value. Therefore, this is the key difference between D value and Z value.
What is F not value?
F0 value is the time in minute for the specified temperature that gives the same thermal lethality as at 121 °C in one minute. Related: Determination of Z-Value. It explains that temperature is not an important factor in thermal sterilization but lethality is important.
What is 12D reduction?
12D concept refers to thermal processing requirements designed to reduce the probability of survival of the most heat resistant C. botulinum spores to 10-12. This helps to determine the time required at process temperature of 121oC to reduce spores of C.
What affects the D-value?
The pH, fat content (which may be related to aw), incubation atmosphere and conditions experienced prior to heating all have an influence on the D-value measured.”
What is F 12D concept?
12D concept refers to thermal processing requirements designed to reduce the probability of survival of the most heat resistant C. botulinum spores to 10-12. This helps to determine the time required at process temperature of 121oC to reduce spores of C. botulinum).
What is F-value in pasteurization?
The F-Value (or P-Value) is therefore the duration (in minutes) of the entire sterilisation or pasteurisation process, at a defined temperature. In pasteurisation applications, especially for drinks, one encounters the term Pasteurisation Units – PU.
What is difference between F0 and FH?
And thus, the F0 value is called Equivalent Exposure Time….Difference Between F0 and Fh Value.
| F0 Value | Fh Value |
|---|---|
| Much more complicated due to steam quality requirements | The lethality of the microbes is less than that of F0 at the same temperature |
