Topic 3 - Food Microbiology Flashcards
What are the 5 most important microbes associated with food?
- viruses
- bacteria
- yeasts
- molds
- parasites
Where are parasites found? How are they transmitted?
- found in raw and undercooked foods
- transmitted by water, soil, or person-to-person contact
How are viruses transported?
food is a transportation medium btw hosts
Do viruses multiply in food?
No, they just remain in food that is under or not cooked
What is the most common virus?
Norovirus
- leading cause of gastroenteritis, the stomach flu
How do molds grow?
- in a tangled mass of mycelium
How do molds replicate?
by spores (which are dispersed through the air) called conidia, visible at the tope of hyphae
What do molds do to food?
- many molds are spoilage organisms
- some molds contribute character to cheeses and fermentations
- not known to cause gastrointestinal distress but some molds cause allergic rxns, respiratory problems and/or long term health consequences
What do yeasts do to food?
- can be spoilage organisms
- perform food fermentations
What are the primary organisms implicated in foodborne disease (on their own or their toxins)?
Bacteria
- Salmonella spp
- Clostridium botulinum
- Staphylococcus aureus
What are the 2 beneficial effects of bacteria?
- probiotics
- fermentations (ex. lactic acid bacteria)
When do vegetative bacteria produce spores?
- in unfavourable conditions
- vegetative bacteria die while spores are ‘pseudodormant’
- spores germinate into vegetative states when favourable conditions return
What are the implications of spores in food products?
- spores have greater resistance to heating, drying and irradiation processing than bacteria
- thermoduric and acid resistant
What are the processing implications of spores in food?
- higher heat and/or longer processing times are required for foods that may contain spores
