Food Preservation

1
Food Preservation

• FCS 3120

2
Purpose of preservation

• To slow down the activity of disease-causing
  bacteria
• To kill bacteria
• To prevent spoilage

3
Ref. Freezing

• Refrigeration
• Slows bacterial action
• No effect on taste or texture
• Freezing
• Stops but does not kill bacterial action
• No effect on taste texture of meats
• Minimal effects on veg.
• Changes texture of fruits

4
Canning

• Boil food in can or jar to kill bacteria seal
  to prevent new bacteria from entering
• Causes changes in taste texture
• Causes changes in nutritional content

5
Dehydration

• Water removed
• Water activity level too low to support bacteria
• Alters taste and texture

6
Freeze-Drying

• Food frozen and vacuum sealed
• Removes all moisture
• Less effect on food taste than dehydration
• Sublimation process

7
Salting Pickling

• Salt draws out moisture
• Salt cold weather
• Pickling uses salt acid
• brine of 10 salt water
• Preserved in vinegar

8
Pasteurizing, Fermenting, Carbonating

• Pasteurizing
• Heating to temp. to kill some bacteria enzymes
  but not high enough to effect taste
• Fermenting
• Uses yeast to produce alcolol which kills
  bacteria (wine)
• Carbonating
• CO2 gas added under pressure eliminate oxygen

9
Cheese-making

• Uses bacteria enzymes acids
• Lactic acid bacteria rennet
• Way of preserving milk

10
Additives

• Substance or mixture of substances other than
  basic foodstuff, which is present in a food as a
  result of any aspect of production, processing,
  storage, or packaging. ( FDA definition)
• GRAS
• Risk vs. Benefit
• 3 classes of chemical additives
• Benzoates
• Nitrites
• Sulphites

11
Additive Functions

• Enhance nutritive value
• Improve flavor
• Improve color
• Extend shelf life
• Improve texture
• Control pH
• Leavening
• Bleaching maturing
• Ease manufacturing problems

12
Irradiation

• Application of ionizing radiation to foods
• Type of radiant energy that has enough energy to
  change atoms by knocking off electrons to form
  ions, but not enough to split the atom Its
  the split atom that causes radioactivity.

13
Why use Irradiaton?

• It is a cold processing technique (without heat
  application) therefore, quality characteristics
  are less affected

14
Benefits of Irradiation

• Reduces or eliminates pathogenic bacteria,
  insects, and parasites
• Reduces spoilage
• Inhibits sprouting delays ripening
• Extends shelf life
• Less use of chemicals

15
Consumer Concerns/Issues

• Food will be radioactive
• Toxic by-products will be produced
• Food quality will suffer
• Is unsafe for workers/environment
• Irradiated foods will not be identifiable

16
Governments Role

• FDA approval
• First approved 1963 for use on wheat flour
• Labeling requirements

17
Governments Role

• FDA approval
• First approved 1963 for use on wheat flour
• Labeling requirements

18
Extent of use

• No widespread use
• Retailers unwilling due to lack of consumer
  acceptance
• Consumer acceptance increases with education