microbiology Flashcards
pt 2
what is the minimum bacteria humans carry
150 billion
what is the “Danger Zone”
41ºF-135ºF
what is the maximum amount of time food can be held in the danger zone
4 hours
remember the higher the temperature (danger zone)
the shorter amount of time food can be left outside
what are the most common microorganisms that affect food
bacteria
why is bacteria the most common microorganisms that affect food
the can live and multiply anywhere and grow on food
what conditions do bacteria need to multiply
food, moisture, warm temp, time, adequate ph
what kind of food causes bacteria to grow faster
high in protein , such as milk, eggs, fish, and eggs
what specific temperature causes bacteria to grow faster
70ºF-135ºF
what is the adequate ph for bacteria to grow
4.5-7.5
what are the types of food that bacteria can grow on called
PHF- potentially hazardous food
why are cantaloups and watermelon considered PHFs
plenty of water, not too acidic, with a lot of nutrients
freezing, drying, and refrigerating food does not ftb bacteria
kill
what does freezing, drying, refrigerating food do to bacteria
keeps bacteria dormant
what happens as soon as you thaw food/remove from fridge
bacteria will continue to grow and double every 20 minutes
what happens when bacteria multiplies
it consumes the food, produces waste (toxins)
what do toxins look/feel like
slime
toxins cannot be killed by
heat or cold
can toxic food be fixed
no under any circumstances
what happens if toxins are ingested
they produce intoxication in people
what are examples of good bacteria
the kind used in preparing cheese, yogurt, sour cream, and other foods
what are spores
a type of bacteria that is able to change into forms that are resistant to heat and dry conditions
how are spores characterized
by the formation of a “shell”
how do spores multiply
they are unable to multiply in that form, once good conditions are found they will return to the bacteria state and continue multiplying
where may spores be formed
improperly processed home canned foods.
all food for sale to the public HAS to be purchased through
an approved source, a commercial kitchen
bacteria will grow best when (ph)
slightly acidic, neutral, or slightly alkaline also containing enough water for growth
what is an acid
any food that falls below a 7 on a pH scale
what is an alkaline
any food above 7 on a pH scale
what is a neutral
7 on the pH scale
where it the area of concern for bacteria on food (pH)
4.5-7.5
what kind of food does not support bacteria growth
food rich in acid such as citric juices, dressings, and mayo
where is salmonella found
human intestines, wild and domestic animals, pets roaches and rodents/ unpasteurized milk
how do you kill salmonella in poultry
cooking at 165ºF for 15 seconds
where is shigella found
human intestines
what does shigella cause in humans
dysentery
how do you pass shigella
not washing your hands after bathroom and touching food that wont be cooked
where is e. coli found
human intestines and that of warm blooded animals
what does e. coli affect
ground beef not cooked at 155ºF
