Transcript File - Wakefield FFA

Control Measures
Control Measures
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Focus on safety and quality
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Food safety control measures -- prevent foodborne
illness.
Food quality control measures -- maximize shelf-life,
slow spoilage, or produce a new product.
Processors use a combination of controls
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One-control system can be harsh making food
unacceptable to the consumer.
Multiple controls is called the hurdle concept and is
commonly used.
C 5.01 -- Control Measures
Hurdle Concept
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Food processors use a combination of control
measures called hurdle concept.
The three primary control measures are:
1.
Controlling water activity and/or pH values of the
food.
2. Adding chemicals, such as additives or substances
like salt, directly to the food.
3. Adjusting the atmosphere surrounding the food
using special packaging methods.
C 5.01 -- Control Measures
1a -- Controlling Water Activity
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Water activity (Aw)
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Minimum, optimum, and maximum values
Yeasts and mold grow at a lower water activity
than do bacteria.
0.85 safe cutoff for pathogen growth
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Based on minimum water activity needed for S.
aureus toxin production.
C 5.01 -- Control Measures
Water activity and foods
Above 0.85
Moist foods
Refrigeration or another barrier
to control pathogen growth
0.60 and 0.85 Intermediate
No refrigeration, short shelf-life
moisture foods because spoilage by yeast and
mold
Below 0.60
Low moisture
foods
Extended shelf-life without
refrigeration
C 5.01 -- Control Measures
Controlling water activity
Method
Foods
Hot air drying
Spray drying
Solid foods like vegetables, fruit, and
fish
Liquids and semi-liquids like milk
Vacuum drying
Liquids like juice
Freeze drying
Variety of foods
Adding salt or sugar
Soy sauce, jams, salted fish
C 5.01 -- Control Measures
1b -- Controlling pH
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Minimum, optimum, and maximum pH
values for microbial growth
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Yeasts and mold grow at low pH.
Pathogenic bacteria do not grow at 4.6 or
below.
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pH controls growth and is not a method to kill
pathogens.
C 5.01 -- Control Measures
Ways to Control pH
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Acidification
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direct addition of acid to a low-acid food
Use organic acids, acetic, lactic, or citric or add high-acid
food to mixture
Direct – predetermined amounts of acids added to
individual finished product
Bath – acid and food combined in large batches and
allowed to equilibrate.
Fermentation
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Lactic acid bacteria produces lactic acid.
C 5.01 -- Control Measures
Measuring pH
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pH meter
 Digital method but expensive
 Easy, the MOST accurate, and sanitary
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Indicator solutions
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Organic dyes used with dropper
Solution turns pink or red in acid; green or blue in base
Neutral solution may turn lilac and might be difficult to read
Not totally accurate
Indicator paper
 Used by dipping
 Turns yellow to red in acids; turns green or blue in bases
 Easy but not completely accurate
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Titration
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Add base with know ph to an acid
Uses burette
Difficult to calculate math so recommended for those with chemistry knowledge
C 5.01 -- Control Measures
2 -- Adding Chemicals
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Preservation method might not prevent growth of all
microorganisms.
Add chemical preservatives, such as:
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sorbates
benzoates
sulfites
nitrites
antibiotics
C 5.01 -- Control Measures
How Chemicals Function?
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Denature proteins.
Inhibit enzymes.
Alter or destroy cell walls.
Alter or destroy cell membranes.
C 5.01 -- Control Measures
Common Chemical Preservatives
Preservative
Mechanism
Benzoates
Inhibit yeast or mold
Sorbates
Inhibit mold
Propionic acid
Inhibit mold
Sulfites
Antioxidant and antimicrobial
Nitrites
Inhibit C. botulinum
Salt
Inhibit pathogens, especially C. botulinum
Antibiotics -- nisin Antimicrobial in cheese
C 5.01 -- Control Measures
Regulating Preservatives
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Chemical preservatives are food additives.
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Approved uses and use levels in FDA’s Food Additive
Status List.
Addressed through product formulation.
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Processor must carefully control the quantity of food
additive for each batch.
Processing conditions must be scientifically established
and followed
C 5.01 -- Control Measures
3 -- Adjusting the Atmosphere
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Packaging does not control the growth of
pathogens, it is limited to the control of
spoilage microorganisms.
Two functions:
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Prevents contamination of the food and/or
Extends the effectiveness of food preservation
methods.
C 5.01 -- Control Measures
Types of Packaging
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Reduced Oxygen Packaging (ROP) – prevents
growth of microorganisms to extend shelf-life
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Vacuum Packaging – air mechanically removed from the
package before sealing
Modified Atmosphere Packaging – flush with nitrogen,
carbon dioxide, and/or oxygen before sealing.
Controlled Atmosphere Packaging – retain atmosphere
throughout shelf-life using an oxygen scavenger in
packaging.
C 5.01 -- Control Measures
Packaging – Key Concerns
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If ROP used, must have barrier to C. botulinum.
Barriers include:
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Water activity below 0.93 with refrigeration
pH below 4.6; salt above 10%
High levels of competing microorganisms
Thermal processing in final container
Freezing with frozen storage and distribution
C 5.01 -- Control Measures