PKSC 2010 sterilization exam
1. 12 logs: 1 F value = ?
2. specific: The thermal death time curve is to each food at each temperature.
3. viscosity, size of container, initial microbial load: What are the three parameters for shelf
stability when using sterilization?
4. conduction, high viscosity foods: What type of heating profile is slow, as heat travels from molecule
to molecule? What type of foods are characterized by this heating profile?
5. convection, low viscosity foods: What type of heating profile is a "rolling boil"? What type of foods
are characterized by this heating profile?
6. value for a specific food at a specific temperature to decrease bacteria by 1
log: What is a D value?
7. 12: How many D values equal an F value?
1/5
, 8. F value, 250: What is the time to destroy 12 orders of magnitude of micro-organisms? What temperature does
this typically occur in Fahrenheit?
9. Z value: What is the temperature increment which speeds up the destruction of micro-organisms by a factor of
1 log or lowers the rate by a factor of 1 log?
10. 8.1 minutes: Solve question 1.
11. 8100 minutes: Solve question 2.
12. 33.75 minutes: Solve question 3.
13. : .
14. direct thermal processing, heat breaks down globular protein matrix, de-
2/5
1. 12 logs: 1 F value = ?
2. specific: The thermal death time curve is to each food at each temperature.
3. viscosity, size of container, initial microbial load: What are the three parameters for shelf
stability when using sterilization?
4. conduction, high viscosity foods: What type of heating profile is slow, as heat travels from molecule
to molecule? What type of foods are characterized by this heating profile?
5. convection, low viscosity foods: What type of heating profile is a "rolling boil"? What type of foods
are characterized by this heating profile?
6. value for a specific food at a specific temperature to decrease bacteria by 1
log: What is a D value?
7. 12: How many D values equal an F value?
1/5
, 8. F value, 250: What is the time to destroy 12 orders of magnitude of micro-organisms? What temperature does
this typically occur in Fahrenheit?
9. Z value: What is the temperature increment which speeds up the destruction of micro-organisms by a factor of
1 log or lowers the rate by a factor of 1 log?
10. 8.1 minutes: Solve question 1.
11. 8100 minutes: Solve question 2.
12. 33.75 minutes: Solve question 3.
13. : .
14. direct thermal processing, heat breaks down globular protein matrix, de-
2/5
