FDSC EXAM 3 QUESTIONS AND
ANSWERS
define preservatives - Correct Answers -substances which are under certain conditions,
either delay the growth of microorganisms without necessarily destroying them or
prevent deterioration of quality during manufacture and distribution
Characteristics of preservatives - Correct Answers -naturally occurring or synthetic
substance that is added to products to prevent decomposition by microbial growth or by
undesirable chemical changes
Amount of preservatives added - Correct Answers -added in low quantities <0.2% which
do not alter the organoleptic and physico-chemical properties of the foods at or only
very little of
drying rate - Correct Answers -typically 4 hours
case hardening - Correct Answers -thick dry outside, serves as insulator for air and heat
food additives - Correct Answers -spices and flavoring agent
food additive developed by itself - Correct Answers -fermentation
Type of chemical preservatives - Correct Answers -traditional
acidulants
gaseous chemical/leavening agents
table sugar - Correct Answers -determined by the ration between the total quantity in
the finished product and the total concentration in the liquid phase
table sugar total concentration in finished product assures food preservation - Correct
Answers -60%
applications of sugar-high sugar - Correct Answers -jellies, preserves, syrups, juice
concentrates
applications of sugar-interaction with other ingredients - Correct Answers -drying and
heating
,applications of sugar-indirect food preservation - Correct Answers -form ethanol-
fermentation
table salt - Correct Answers -used in brines or directly applied
function as seasoning or preservative
removing water by osmosis
more=greater protection
lactic acid - Correct Answers -main product of many food fermentations
formed by microbial degradation of sugars
decreases the pH to levels unfavorable for growth of spoilage
spoilage organisms - Correct Answers -putrefactive, anaerobes, butric-acid
yeasts and molds can be controlled by - Correct Answers -sorbate and benzoate
acetic acid - Correct Answers -inhibits many species of bacteria, yeasts, and (lesser
extent) molds
product of lactic-acid fermentation
main applications of vinegar
contents of vinegar - Correct Answers -4-8% acetic acid (avg 5%)
pH ~2.4
pKa- 4.75
other acidulants - Correct Answers -malic and tartaric
citric
ascorbic acid
malic and tartaric acid - Correct Answers -acidify and preserve fruit sugar preserves,
jams, jellies
citric acid - Correct Answers -found in citrus fruits
used in beverages
highly soluble in water
less effective microbial agent
lipophilic acid food preservative - Correct Answers -benzoic and sorbic
benzoic acid / benzoates - Correct Answers -berries (cranberries) and other fruits
benzoic acid inhibits - Correct Answers -yeasts & molds
primary use of benzoic acid, pKA, and percent used - Correct Answers -antifungal , 4.19
, 0.1%
, bacteria resistant to benzoic acid - Correct Answers -Zygosaccharomyces bailii
Applications and percent use of benzoic acid/benzoates - Correct Answers -beverages-
0.03%
syrups-0.1%
olives, pickles, relishes-0.1%
jams, jellies-0.1%
fruit products-0.1%
Sorbic acid/sorbates characteristics - Correct Answers -isolated from oil of unripe
rowanberries
rowans
patent issued 1945
control microbial growth
genus of sorbic acid - Correct Answers -Sorbus
primary use of sorbic acid and pKa - Correct Answers -yeasts, molds, bacteria , 4.75
bacteria resistant to sorbic acid - Correct Answers -Z. bailii , Zygosacchromyces rouxii ,
Penicillium spp. , lactic acid bacteria
Applications and percent use of sorbic acid - Correct Answers -Fruits and vegetables-
0.3%
fruit juices-0.3%
pickles-0.3%
sauerkraut-0.3%
syrups-0.3%
jellies and jams-0.3%
high moisture dehydrated fruits-0.3%
types of gaseous chemical preservatives - Correct Answers -sulphur dioxide , sulphites ,
sodium metabisulfite
Function of gaseous chemical - Correct Answers -antimicrobial , antioxidant , and very
soluble in cold water
Function of metabisulfite - Correct Answers -most effective at low pH
effective against yeasts and mold
used in fruit products and wine
cause allergic reactions
standard solution for sulfur dioxide - Correct Answers -85g in 100ml at 25C
ANSWERS
define preservatives - Correct Answers -substances which are under certain conditions,
either delay the growth of microorganisms without necessarily destroying them or
prevent deterioration of quality during manufacture and distribution
Characteristics of preservatives - Correct Answers -naturally occurring or synthetic
substance that is added to products to prevent decomposition by microbial growth or by
undesirable chemical changes
Amount of preservatives added - Correct Answers -added in low quantities <0.2% which
do not alter the organoleptic and physico-chemical properties of the foods at or only
very little of
drying rate - Correct Answers -typically 4 hours
case hardening - Correct Answers -thick dry outside, serves as insulator for air and heat
food additives - Correct Answers -spices and flavoring agent
food additive developed by itself - Correct Answers -fermentation
Type of chemical preservatives - Correct Answers -traditional
acidulants
gaseous chemical/leavening agents
table sugar - Correct Answers -determined by the ration between the total quantity in
the finished product and the total concentration in the liquid phase
table sugar total concentration in finished product assures food preservation - Correct
Answers -60%
applications of sugar-high sugar - Correct Answers -jellies, preserves, syrups, juice
concentrates
applications of sugar-interaction with other ingredients - Correct Answers -drying and
heating
,applications of sugar-indirect food preservation - Correct Answers -form ethanol-
fermentation
table salt - Correct Answers -used in brines or directly applied
function as seasoning or preservative
removing water by osmosis
more=greater protection
lactic acid - Correct Answers -main product of many food fermentations
formed by microbial degradation of sugars
decreases the pH to levels unfavorable for growth of spoilage
spoilage organisms - Correct Answers -putrefactive, anaerobes, butric-acid
yeasts and molds can be controlled by - Correct Answers -sorbate and benzoate
acetic acid - Correct Answers -inhibits many species of bacteria, yeasts, and (lesser
extent) molds
product of lactic-acid fermentation
main applications of vinegar
contents of vinegar - Correct Answers -4-8% acetic acid (avg 5%)
pH ~2.4
pKa- 4.75
other acidulants - Correct Answers -malic and tartaric
citric
ascorbic acid
malic and tartaric acid - Correct Answers -acidify and preserve fruit sugar preserves,
jams, jellies
citric acid - Correct Answers -found in citrus fruits
used in beverages
highly soluble in water
less effective microbial agent
lipophilic acid food preservative - Correct Answers -benzoic and sorbic
benzoic acid / benzoates - Correct Answers -berries (cranberries) and other fruits
benzoic acid inhibits - Correct Answers -yeasts & molds
primary use of benzoic acid, pKA, and percent used - Correct Answers -antifungal , 4.19
, 0.1%
, bacteria resistant to benzoic acid - Correct Answers -Zygosaccharomyces bailii
Applications and percent use of benzoic acid/benzoates - Correct Answers -beverages-
0.03%
syrups-0.1%
olives, pickles, relishes-0.1%
jams, jellies-0.1%
fruit products-0.1%
Sorbic acid/sorbates characteristics - Correct Answers -isolated from oil of unripe
rowanberries
rowans
patent issued 1945
control microbial growth
genus of sorbic acid - Correct Answers -Sorbus
primary use of sorbic acid and pKa - Correct Answers -yeasts, molds, bacteria , 4.75
bacteria resistant to sorbic acid - Correct Answers -Z. bailii , Zygosacchromyces rouxii ,
Penicillium spp. , lactic acid bacteria
Applications and percent use of sorbic acid - Correct Answers -Fruits and vegetables-
0.3%
fruit juices-0.3%
pickles-0.3%
sauerkraut-0.3%
syrups-0.3%
jellies and jams-0.3%
high moisture dehydrated fruits-0.3%
types of gaseous chemical preservatives - Correct Answers -sulphur dioxide , sulphites ,
sodium metabisulfite
Function of gaseous chemical - Correct Answers -antimicrobial , antioxidant , and very
soluble in cold water
Function of metabisulfite - Correct Answers -most effective at low pH
effective against yeasts and mold
used in fruit products and wine
cause allergic reactions
standard solution for sulfur dioxide - Correct Answers -85g in 100ml at 25C
