Midterm T.3

Question 1

Parasites

Answer 1

in raw and undercooked foods

transmitted by water, soil, person to person contact

cryptosporidium sp

trichinella larva

Question 2

Virus

Answer 2

food is a transportation, do not multiply, remain in under or over-cooked foods

Norovirus (cause of gastroenteritis, stomach flu)

Hepatitis A: liver disease, contaminated food or water

Question 3

Molds

Answer 3

grow in mass (mycelium)

replicate by spores (conidia) on hyphae

anchor mold by rhizoids

Aspergillus fumigatus
Penicillium glabrum

spoilage organisms

not known to cause gastrointestinal distress but may cause allergic reactions, respiratory problems, long term health consequences (some produce mycotoxins)

Question 4

Yeasts

Answer 4

can be spoiling organisms

food fermentations

Question 5

Bacteria

Answer 5

primary organisms

salmonella spp
clostridium botulinum
staphylococcus aureus
probiotics: bacteria with health benefits
fermentations (lactic acid bacteria)

Question 6

Vegetative Bacteria

Answer 6

produce spores in unfavourable conditions

vegetative bacteria die while spores are pseudo dormant

spores germinate into vegetative states when favourable conditions return

starvation state
onset state
commitment state
engulfment state
maturation state
mother cell lysis
germination
vegetative state

Question 7

Spores have greater resistance to

Answer 7

heating, drying, irradiation

thermoduric and acid resistant

Question 8

Most pathogens grow at pH values between

Answer 8

4.6 - 9

Question 9

Microbes are categorized according to the T where they grow best:

Answer 9

psychrophiles
mesophiles
thermophiles

Question 10

Bacteria can be categorized by their needs for oxygen

Answer 10

obligate aerobes bacillus sp

microaerophilic bacteria campylobacter sp

indifferent bacteria lactobacillus sp

facultative anaerobes escherichia sp

obligate anaerobes clostridium sp