Transcript Thermal Preservation

Thermal Preservation
Definition
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Adding or removing heat to alter shelflife. Shelf-life -- time food can be
stored and still maintain its quality
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Heat processing -- adding heat to a food
to destroy enzymes and some spoilage
and pathogenic bacteria.
Cold processing -- removing heat from
food to slow deterioration from enzymes
and bacteria.
D 9.01 -- Thermal Preservation
Types of Thermal Preservation
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Heat processing
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Blanching
Commercial sterilization
Pasteurization
Sterilization
Dehydration
Canning
Cold processing
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Refrigeration
Freezing
D 9.01 -- Thermal Preservation
Blanching
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Immersing food in
boiling water or steam
to destroy enzymes.
Often used before
freezing or drying
foods.
Product shelf-life is
short.
D 9.01 -- Thermal Preservation
Commercial Sterilization
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Combines heat and
vacuum seal to destroy
spoilage and pathogenic
microorganisms.
Product shelf-life is long.
Examples include water
bath, retort, or
hydrostatic cooker and
cooler
D 9.01 -- Thermal Preservation
Pasteurization
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A low heat treatment
that destroys pathogenic
microorganisms and
stops enzyme activity
Products have a medium
shelf-life.
Examples include batch,
high temperature, and
short-time.
D 9.01 -- Thermal Preservation
Sterilization
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A high temperature
heat treatment that
destroys all
microorganisms.
Products have a
long shelf-life.
Examples include
aseptic canning.
D 9.01 -- Thermal Preservation
Dehydration
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Low temperature heat
treatment that involves the
removal of water as a means
to prevent microbial growth.
Products have a long shelflife.
Examples include tray, belt,
drum, spray, vacuum, freezedrying, sun, and oven drying
D 9.01 -- Thermal Preservation
Concentration
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Removal of a portion of
water from food to
prevent microbial growth.
Products have a medium
shelf-life.
Examples -- open kettle,
heat evaporation, vacuum
evaporation, and filtration
D 9.01 -- Thermal Preservation
Refrigeration
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Slows enzyme activity
and microbial growth.
Products have a short
shelf-life.
D 9.01 -- Thermal Preservation
Freezing
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Slows enzyme
activity and
microbial growth
Products have a
long shelf-life
D 9.01 -- Thermal Preservation