BIOS 111 Lecture Notes - Lecture 23: Ultra-High-Temperature Processing, Pascalization, Clostridium
Document Summary
Autoclaves: high pressure makes the temperature go up because steam isn"t allowed out. To keep an autoclave functioning, test it every few months. Hospitals will test theirs much more often so they don"t get lawsuits filed against them. 121 degrees celsius for 15 minutes to kill all spores. Bacillus stearothermophilus is the most heat resistant. To test an autoclave, we put strips of these spores in to see if they"re killed. As we increase pressure, liquid temperatures increase. For most autoclaves we stop as 15 psi because 121 degrees celsius is sufficient. If working in denver, you need higher pressures or longer times to kill the spores. It takes a longer time to heat up more liquid solution. It needs to heat up and kill all throughout the liquid. Most of the time we drink pasteurized milk. Sterile milk will keep a long period of time. Milk has protein so sterilizing it with an autoclave makes it undrinkable.
