7 - Control of Growth Flashcards
Sterilization
removal of all microbes
Commercial sterilization
heat enough to kill Clostridium botulinum (but not enough to degrade food quality and thermophiles remain, but will not grow at food storage temp)
Disinfection
destroy harmful microbes (chemical, UV radiation, boiling water, steam)
Antiseptic
a disinfectant used on living tissue
Sanitization
lower microbe levels to public health levels (high temp washing, dip in chemical disinfectant - reducing level not destroying
“cide”
kill
“stasis”
inhibit growth
Bacteria death is at a _________ rate.
constant
What are the 3 mechanisms used to kill microbes?
- plasma membrane (cause cellular components to leak)
- break bonds in proteins/enzymes (denature proteins and stop enzymes vital to cell activity)
- nucleic acids DNA/RNA (can’t replicate to make proteins/enzymes)
What are six physical methods used to kill microbes?
- Heat
- Filter
- Refrigeration
- Desiccation
- Osmotic pressure
- Radiation
What mechanism does heat use to kill microbes?
denatures enzymes/proteins
Does pasteurization sterilize?
does not sterilize just eliminates pathogens
What is the disk diffusion method?
determine how well a chemical kills a specific bacteria - make a lawn of bacteria and add discs soaked with chemical there will be a zone of inhibition
What does a large zone of inhibition mean?
the bigger the zone the more effective the agent
What mechanism do halogens use to kill microbes?
destroy proteins (enzymes) - betadine (iodine) /clorox (chlorine)
