1. Control Measures

2. Control Measures Focus on safety and quality
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
One-control system can be harsh making food unacceptable to the consumer.
Multiple controls is called the hurdle concept and is commonly used.
C Control Measures

3. Hurdle Concept
Food processors use a combination of control measures called hurdle concept.
The three primary control measures are:
Controlling water activity and/or pH values of the food.
Adding chemicals, such as additives or substances
like salt, directly to the food.
Adjusting the atmosphere surrounding the food using special packaging methods.
C Control Measures

4. 1a -- Controlling Water Activity
Water activity (Aw)
Minimum, optimum, and maximum values
Yeasts and mold grow at a lower water activity than do bacteria.
0.85 safe cutoff for pathogen growth
Based on minimum water activity needed for S. aureus toxin production.
C Control Measures

5. Water activity and foods
Above 0.85
Moist foods
Refrigeration or another barrier to control pathogen growth
0.60 and 0.85
Intermediate moisture foods
No refrigeration, short shelf-life because spoilage by yeast and mold
Below 0.60
Low moisture foods
Extended shelf-life without refrigeration
C Control Measures

6. Controlling water activity
Method
Foods
Hot air drying
Solid foods like vegetables, fruit, and fish
Spray drying
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 Control Measures

7. 1b -- Controlling pH
Minimum, optimum, and maximum pH values for microbial growth
Yeasts and mold grow at low pH.
Pathogenic bacteria do not grow at 4.6 or below.
pH controls growth and is not a method to kill pathogens.
C Control Measures

8. Ways to Control pH Acidification Fermentation
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
Lactic acid bacteria produces lactic acid.
C Control Measures

9. Measuring pH pH meter Indicator solutions Indicator paper Titration
Digital method but expensive
Easy, the MOST accurate, and sanitary
Indicator solutions
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
Titration
Add base with know ph to an acid
Uses burette
Difficult to calculate math so recommended for those with chemistry knowledge
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10. 2 -- Adding Chemicals
Preservation method might not prevent growth of all microorganisms.
Add chemical preservatives, such as:
sorbates
benzoates
sulfites
nitrites
antibiotics
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11. How Chemicals Function?
Denature proteins.
Inhibit enzymes.
Alter or destroy cell walls.
Alter or destroy cell membranes.
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12. Common Chemical Preservatives
Mechanism
Benzoates
Inhibit yeast or mold
Sorbates
Inhibit mold
Propionic acid
Sulfites
Antioxidant and antimicrobial
Nitrites
Inhibit C. botulinum
Salt
Inhibit pathogens, especially C. botulinum
Antibiotics -- nisin
Antimicrobial in cheese
C Control Measures

13. Regulating Preservatives
Chemical preservatives are food additives.
Approved uses and use levels in FDA’s Food Additive Status List.
Addressed through product formulation.
Processor must carefully control the quantity of food additive for each batch.
Processing conditions must be scientifically established and followed
C Control Measures

14. 3 -- Adjusting the Atmosphere
Packaging does not control the growth of pathogens, it is limited to the control of spoilage microorganisms.
Two functions:
Prevents contamination of the food and/or
Extends the effectiveness of food preservation methods.
C Control Measures

15. Types of Packaging
Reduced Oxygen Packaging (ROP) – prevents growth of microorganisms to extend shelf-life
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 Control Measures

16. Packaging – Key Concerns
If ROP used, must have barrier to C. botulinum.
Barriers include:
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 Control Measures