FSTC 326 EXAM 2 Questions and
Answers 100% Solved | Graded A+
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.
1
©JOSHCLAY 2024/2025. YEAR PUBLISHED 2024.
,(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 ______
2
©JOSHCLAY 2024/2025. YEAR PUBLISHED 2024.
,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 ___
3
©JOSHCLAY 2024/2025. YEAR PUBLISHED 2024.
, 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
4
©JOSHCLAY 2024/2025. YEAR PUBLISHED 2024.
Answers 100% Solved | Graded A+
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.
1
©JOSHCLAY 2024/2025. YEAR PUBLISHED 2024.
,(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 ______
2
©JOSHCLAY 2024/2025. YEAR PUBLISHED 2024.
,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 ___
3
©JOSHCLAY 2024/2025. YEAR PUBLISHED 2024.
, 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
4
©JOSHCLAY 2024/2025. YEAR PUBLISHED 2024.
