FSC 342 Final Exam Questions with Correct Answers Latest Update 2026/2027
sources of microorganisms in food - Answers - soil/water
- air/dust
- plants/plant products
- animals (hide, gastrointestinal, respiratory tract)
- animal feed
- humans (skin, gastrointestinal, respiratory tract)
- food/utensils/equipment
- environment
- fermented foods
characteristics of bacteria - Answers - free-living organisms
- unicellular (prokaryotes)
- colony morphology
- size
- binary fission (asexual)
- nutrient requirements
- growth curve/growth requirements
spoilage organisms - Answers - may grow at refrigerated temperatures
- can double their number in 20 mins
- large # of microorganisms and their waste products cause objectionable changes in odor,
taste, and texture
purpose of microorganisms - Answers survive and multiply
foods produced using microorganisms - Answers - bread
- beer
- wine
- cheese
,- yogurt
- sauerkraut
- pickles
- miso
- pepperoni
- fruit
- sausage
- kimchi
- kombucha
- vinegar
- chocolate
- coffee
- soy sauce
- hot sauce
changing picture of foodborne illness - Answers - low level of contamination
- imported vs. domestic products
- large centralized production
- longer shelf life for products
- decreased preservative usage
intrinsic parameters - Answers - inherent parameters
- properties that exist as part of the food product itself
- aka food composition
- nature's way of preventing microbial spoilage
list some intrinsic parameters - Answers - water activity (aw)
- pH
, - redox potential
- nutrient content
- antimicrobial constituents
- vitamins and related growth factors
- biological structures
- competitive microflora
no proliferation at water activity... - Answers <0.6
water activity - Answers - related to moisture content
- one of the oldest methods of preservation
- the ratio of the water vapor pressure of food to vapor pressure of pure water at the same
temperature
pure water water activity value - Answers 1.00
35% (v/v) glycerin and water solution water activity value - Answers 0.86
22% (m/v) NaCl solution water activity value - Answers 0.86
fresh foods water activity value - Answers >0.95
aw= - Answers p/po
p= vapor pressure of a solution or food
- po= vapor pressure of solvent (pure water)
RH= - Answers 100 x aw
effects of low aw on microbial growth - Answers - increase lag phase
- decrease growth rate
- decrease maximum population
best microbial growth at pH... - Answers 6.0-7.5
few organisms grow at pH - Answers <4.0
no growth of C. botulinum at pH - Answers </= 4.6
acidified food - Answers - AF
sources of microorganisms in food - Answers - soil/water
- air/dust
- plants/plant products
- animals (hide, gastrointestinal, respiratory tract)
- animal feed
- humans (skin, gastrointestinal, respiratory tract)
- food/utensils/equipment
- environment
- fermented foods
characteristics of bacteria - Answers - free-living organisms
- unicellular (prokaryotes)
- colony morphology
- size
- binary fission (asexual)
- nutrient requirements
- growth curve/growth requirements
spoilage organisms - Answers - may grow at refrigerated temperatures
- can double their number in 20 mins
- large # of microorganisms and their waste products cause objectionable changes in odor,
taste, and texture
purpose of microorganisms - Answers survive and multiply
foods produced using microorganisms - Answers - bread
- beer
- wine
- cheese
,- yogurt
- sauerkraut
- pickles
- miso
- pepperoni
- fruit
- sausage
- kimchi
- kombucha
- vinegar
- chocolate
- coffee
- soy sauce
- hot sauce
changing picture of foodborne illness - Answers - low level of contamination
- imported vs. domestic products
- large centralized production
- longer shelf life for products
- decreased preservative usage
intrinsic parameters - Answers - inherent parameters
- properties that exist as part of the food product itself
- aka food composition
- nature's way of preventing microbial spoilage
list some intrinsic parameters - Answers - water activity (aw)
- pH
, - redox potential
- nutrient content
- antimicrobial constituents
- vitamins and related growth factors
- biological structures
- competitive microflora
no proliferation at water activity... - Answers <0.6
water activity - Answers - related to moisture content
- one of the oldest methods of preservation
- the ratio of the water vapor pressure of food to vapor pressure of pure water at the same
temperature
pure water water activity value - Answers 1.00
35% (v/v) glycerin and water solution water activity value - Answers 0.86
22% (m/v) NaCl solution water activity value - Answers 0.86
fresh foods water activity value - Answers >0.95
aw= - Answers p/po
p= vapor pressure of a solution or food
- po= vapor pressure of solvent (pure water)
RH= - Answers 100 x aw
effects of low aw on microbial growth - Answers - increase lag phase
- decrease growth rate
- decrease maximum population
best microbial growth at pH... - Answers 6.0-7.5
few organisms grow at pH - Answers <4.0
no growth of C. botulinum at pH - Answers </= 4.6
acidified food - Answers - AF
