Module 3 Pathogens Flashcards
Advice given to questionable food
when in doubt, throw it out
2 categories of organisms
Spoilage organisms (food smells, looks rotten). Typically don’t cause illness.
Pathogens do cause illness. Usually invisible and undetectable.
Best before vs expiry
Not the same
Best before, just a promise from manufacture about freshness and quality. Just for food that expires before 90 days (bread cheese and such)
Expiry, don’t sell or consume past this date. Not suddenly a danger. But nutritional quality can’t be guaranteed. (just for baby formula, vitamins, meal replacement drinks)
Where do organisms come from?
Dust. So all food has to be coverd.
Soil. Everything must be washed with scrub brush.
Food handler sickness.
- Poor hand hygeine while infected.
- colonization. Stuff on skin, scalp that doesn’t make sick but just has be get inside body. (staph aureus is constantly on skin and can cause problems)
Carrier
Someone who carries it, sheds it in bodily waste, but does not show symptoms.
Can spread through poor hygiene habits.
Infected vs Colonizer vs Carrier
infected and showing symptoms
on skin
infected but no symptoms
6 things needed for bacterial growh
Can you prevent food borne illness by controlling for at least 1 thing?
water (lots water doesn’t mean it’s necessarily available or pure for bacteria. If dissolved with sugars and alt it’s often useless to bacteria. This is why bread and jerky last long time.)
food (carbs and protein)
temperature (4-60 C)
ph (closer to neutral, above 4.5)
oxygen (some food need O, some don’t, just know for the specific food)
pH (above 4.5 start to get dangerous)
time (2 hours at 20-22 C for potentially hazardous food, does not reset upon fridging. Above 32 (like many kitchens) it becomes the 1 hour rule)
Apparently yes you can
Does heat destroy spores?
No. this is why we don’t just reheat leftovers
How fast can bacteria reproduce
15-20 minutes
Do spores usually cause illness when injested?
no
Super dangerous bacteria
Why?
Clostridium Botulinum. Botulusim
Death within hours
But you can just poop out the spores.
The danger is from poorly canned food. They prefer non oxygen environment.
Boiling water doesn’t kill spores, but makes it more dangerous because oxygen is removed in process.
How to control with pH?
pH. foods below 4.5 is good against botulism and other pathogens.
Fruit generally below 4.5.
Vegetables and meat generally above.
How to control with pressure cooker
pressure cooker that can go above 120 C
But cooking in an oven wont do it because the food may not reach the same temperature as the oven itself.
How fast can bacteria grow per hour
X8 per hour
X16 per 2 hours
X 1 billion per 10 hours
If potentially hazardous is: - high protein - neutral ph - lots of moisture, which of these are potentially hazardous: Crackers Clam Chowder Garden Salad Roast Chicken Hamburger Dry pasta
Chowder
Chicken
Hamburger
What are the dangers from produce?
Often not dangerous from surface, but when cut it releases nutrients.
Fruit with bruises, pathogens can enter and spread this way.
Unpasteurized fruit juices
Can cause e coli.
Vegetables cooked in oil, creates non oxygen environment.
Cooling guidelines
(Temperature speed)
(7 cooling methods tips)
Max 6 hours to cool food through danger zone (4-60)
STAGE 1
Get from 60 - 20 c within 2 hours. If more, then it must be discarded.
STAGE 2
from 20 to 4 within 4 hours
Sounds like a lot, but fat portions of rice and such take a long time to get there. a cornish hen takes 4 hours to do it. So: - use ice bath - ice wand - stir - store in shallow containers - divide into small portions - Partially cover to protect contamination but allow steam and moisture to escape - put in fridge right away
Potatos are likely to contain
Botulinum
Salmonella symptoms
diarrhea, fever, and stomach cramps
