FSTC 326 EXAM 2 2024/2025 questions and answers | verified
what are metabolically dormant - bacterial endospores (spores)
what are more process-tolerant verses vegetative cells - bacterial endospores (spores)
the three "philics" that describe bacterial endospores - thermophilic, mesophilic, and
psychrotrophic
what are bacterial endospores - they are bacterial organisms that are gram positive
c. bot and c. perfringens belong to what class of pathogenic organism - toxigenic clostridium spp.
b. cereus and b. thuringiensis belong to what class of pathogenic organism - toxigenic bacillus spp.
why are spores problematic for food safety in cooked foods and spoilage in foods - they can
survive cooking. they are important in low-acid foods (ph >4.6) packaged in cans, bottles, pouches, or
other hermetically (vacuum) sealed containers (ex, canned foods) that are processed by heat. (Diseases
and spoilage caused by sporeformers are usually associated with thermally processed foods, since heat
kills vegetative cells but allows survival and growth of spore-forming organisms)
psychrotrophic sporeformers cause spoilage of - refrigerated foods
FDA and USDA define low-acid canned foods as one with a final pH of ____ and water activity of _______
- >4.6; >0.85 (4.6 pH criterion for considered low acid food. C. botulism stops growth at)
low-acid canned foods are packaged in hermetically (airtight) sealed containers. These cans must be
processed by heat to achieve..... - commercial sterility
commercial sterility? - uses heat to inactivate foodborne pathogens and spoilage microorganisms
that can grow in the food. It indicates a shelf-stable product with a negligible level of microbial survival.
,primary processing goal for low-acid canned foods? - inactivation of C. botulinum spores
most heat-resistant microbial pathogen? - C. botulinum
The severity of the heat treatment required depends on the class of food, its spore content, pH, storage
conditions, and other factors. For example, canned low-acid vegetables and uncured meats usually
receive a ______ process or "botulinum cook". Some foods and ingredients, such as mushrooms, may
contain high spore level and requires more than a 12D process to prevent spoilage - 12D
example of pathogen of concern? - c. botulism. (Most processed tolerant)
time required for a 1-log reduction in viability at a given temperature - D value
one log kill is ___% reduction. 12D is a ____% kill - 90%; 99.9%
temperature change required to alter the D value by a factor of 10 - Z value
t/f acidification or aw (water activity) reduction can't produce commercial sterility - false (it can!)
characteristics of clostridium botulinum - bacilli (rod shaped), obtain energy by fermentation,
obligate anaerobe, neurotoxin (highly potent), pathogen of concern, foodborne intoxicating pathogen
(adults) - causes botulism
three species of Sporeformers of public health significance....? - C. botulinum, C. perfringens, and
B. cereus (cause foodborne disease)
B. cereus can produce a heat-labile enterotoxin causing ___
and a heat-stable toxin causing ___ in humans - diarrhea; emesis (vomiting)
, this sporeformer is widespread in soils and in the intestinal tracts of humans and certain animals. They
grow extremely rapidly in high-protein foods. production of diarrheal enterotoxin - c. perfringens
spores naturally present in foods and the cannery environment contribute to spoilage problems. dry
ingredients such as ____, ___, ____,& ____ often contain high spore levels. - sugar, starches,
flours, and spices
spore populations can also accumulate in a food-processing plant, such as ______ spores on heated
equipment and saccharolytic clostridia in plants processing sugar-rich foods such as fruits. -
thermophilic
the principal classes of sporeformers causing spoilage are thermophilic (listed on the slides. the book has
others).... - flat-sour organisms, thermophilic anaerobes, putrefactive anaerobes,
major sporeformer responsible for flat-sour spoilage? what are the defects? - thermophilic
bacillus spp.
defects include: no gas, pH lowered, and may have abnormal odor and cloudy liquor
major sporeformer responsible for thermophilic anaerobe spoilage? what are the defects? -
thermophilic clostridium spp.
defects include: can swell (excess gas), may burst. anaerobic end products give sour, fermedted, or
butyric odor. (typical foods are corn and spinach)
major sporeformer responsible for anaerobic putrefactive spoilage? what are the defects? - c.
sporogenes
defects include: plentiful gas. disgusting putrid odor. putrefaction occurs (protein breakdown). pH often
increased. (typical foods are corn and asparagus)
describe sulfur stinker spoilage - H2S production givens rotten egg odors. precipitation of iron
sulfide gives black appearance to food (black speck spoilage)
describe psychrotropic clostridial spoilage - vacuum-packed refrigerated meat products; package
blowing (gas), discoloration, off-odors
what are metabolically dormant - bacterial endospores (spores)
what are more process-tolerant verses vegetative cells - bacterial endospores (spores)
the three "philics" that describe bacterial endospores - thermophilic, mesophilic, and
psychrotrophic
what are bacterial endospores - they are bacterial organisms that are gram positive
c. bot and c. perfringens belong to what class of pathogenic organism - toxigenic clostridium spp.
b. cereus and b. thuringiensis belong to what class of pathogenic organism - toxigenic bacillus spp.
why are spores problematic for food safety in cooked foods and spoilage in foods - they can
survive cooking. they are important in low-acid foods (ph >4.6) packaged in cans, bottles, pouches, or
other hermetically (vacuum) sealed containers (ex, canned foods) that are processed by heat. (Diseases
and spoilage caused by sporeformers are usually associated with thermally processed foods, since heat
kills vegetative cells but allows survival and growth of spore-forming organisms)
psychrotrophic sporeformers cause spoilage of - refrigerated foods
FDA and USDA define low-acid canned foods as one with a final pH of ____ and water activity of _______
- >4.6; >0.85 (4.6 pH criterion for considered low acid food. C. botulism stops growth at)
low-acid canned foods are packaged in hermetically (airtight) sealed containers. These cans must be
processed by heat to achieve..... - commercial sterility
commercial sterility? - uses heat to inactivate foodborne pathogens and spoilage microorganisms
that can grow in the food. It indicates a shelf-stable product with a negligible level of microbial survival.
,primary processing goal for low-acid canned foods? - inactivation of C. botulinum spores
most heat-resistant microbial pathogen? - C. botulinum
The severity of the heat treatment required depends on the class of food, its spore content, pH, storage
conditions, and other factors. For example, canned low-acid vegetables and uncured meats usually
receive a ______ process or "botulinum cook". Some foods and ingredients, such as mushrooms, may
contain high spore level and requires more than a 12D process to prevent spoilage - 12D
example of pathogen of concern? - c. botulism. (Most processed tolerant)
time required for a 1-log reduction in viability at a given temperature - D value
one log kill is ___% reduction. 12D is a ____% kill - 90%; 99.9%
temperature change required to alter the D value by a factor of 10 - Z value
t/f acidification or aw (water activity) reduction can't produce commercial sterility - false (it can!)
characteristics of clostridium botulinum - bacilli (rod shaped), obtain energy by fermentation,
obligate anaerobe, neurotoxin (highly potent), pathogen of concern, foodborne intoxicating pathogen
(adults) - causes botulism
three species of Sporeformers of public health significance....? - C. botulinum, C. perfringens, and
B. cereus (cause foodborne disease)
B. cereus can produce a heat-labile enterotoxin causing ___
and a heat-stable toxin causing ___ in humans - diarrhea; emesis (vomiting)
, this sporeformer is widespread in soils and in the intestinal tracts of humans and certain animals. They
grow extremely rapidly in high-protein foods. production of diarrheal enterotoxin - c. perfringens
spores naturally present in foods and the cannery environment contribute to spoilage problems. dry
ingredients such as ____, ___, ____,& ____ often contain high spore levels. - sugar, starches,
flours, and spices
spore populations can also accumulate in a food-processing plant, such as ______ spores on heated
equipment and saccharolytic clostridia in plants processing sugar-rich foods such as fruits. -
thermophilic
the principal classes of sporeformers causing spoilage are thermophilic (listed on the slides. the book has
others).... - flat-sour organisms, thermophilic anaerobes, putrefactive anaerobes,
major sporeformer responsible for flat-sour spoilage? what are the defects? - thermophilic
bacillus spp.
defects include: no gas, pH lowered, and may have abnormal odor and cloudy liquor
major sporeformer responsible for thermophilic anaerobe spoilage? what are the defects? -
thermophilic clostridium spp.
defects include: can swell (excess gas), may burst. anaerobic end products give sour, fermedted, or
butyric odor. (typical foods are corn and spinach)
major sporeformer responsible for anaerobic putrefactive spoilage? what are the defects? - c.
sporogenes
defects include: plentiful gas. disgusting putrid odor. putrefaction occurs (protein breakdown). pH often
increased. (typical foods are corn and asparagus)
describe sulfur stinker spoilage - H2S production givens rotten egg odors. precipitation of iron
sulfide gives black appearance to food (black speck spoilage)
describe psychrotropic clostridial spoilage - vacuum-packed refrigerated meat products; package
blowing (gas), discoloration, off-odors
