The Microbiology of Food

Question 1

food spoilage

Answer 1

• any change in appearance, smell, or taste of a food that makes it unpalatable to the consumer
• may be safe to eat

Question 2

What are methods of food preservation?

Answer 2

• removal of microbes (filtration)
• low temp (fridge at 4C or freezer at -20C)
• high temp (cooking, canning, pasteurization)

Question 3

danger zone

Answer 3

5-60C

Question 4

intrinsic factors that control growth of microorganisms

Answer 4

• pH (low favors yeast and mold)
• presence and availability of water (lower water activity inhibits microbial growth)
• redox potential (lower favors the grow of anaerobic bacteria)
• physical structure (grinding and mixing promotes growth)
• antimicrobial substances (coumarins, lysozyme, allicin)

Question 5

extrinsic factors that control growth of microorganisms

Answer 5

• temperature (lower temperatures slow microbial growth)
• relative humidity (higher humidity promotes microbial growth)
• atmosphere (oxygen promotes growth, can use shrink wrap and vacuum technologies to package food in controlled atmospheres)