1. PRESERVATION From foukeffa.org Written by Teri Micke
Ag Student Texas A&M
GA Ag Ed Curriculum Office
To accompany the Georgia Agriculture Education Curriculum Lesson
June, 2002

2. WHAT IS PRESERVATION?
the treatment of food to keep it from spoiling

3. PALATABLE
an agreeable taste and/or texture

4. CONDUCTION heating through direct contact
example: roasting marshmellows, grilling hamburgers on stove top

5. CONVECTION heating through water or air
example: boiling water, using oven

6. RADIATION
heated through electromagnetic spectrum
example: microwave

7. PASTEURIZATION
destroy pathogenic microorganisms but not spoilage microorganisms
example: milk

8. TYPES OF PRESERVATION 1. canning - around for over 200 yrs 2 ways
a. hot fill - heated before put in can
b. canner’s brine - liquid (sugar/salt mix) added

9. 2. Refrigeration - above freezing point 28 to 65 degrees F; short term storage
3. Freezing - actually freezing the water in the food

10. a. mechanical: heat (sunlight), wind, smoke/heat
4. Drying
a. mechanical: heat (sunlight), wind, smoke/heat
examples: grapes to raisins, meat to jerky
b. freeze drying: used by astronauts, just add water
examples: milk replacers

11. c. chemical drying
add salt and sugar
example: ham

12. 5. Fermentation - involves microorganisms (yeast, mold, bacteria)
2 ways:
a. aerobic: with air
b. anaerobic: without air

13. 6. Irradiation: expose food to ionizing radiation like x-rays, makes food sterile
veg/spices easy to treat
meats hard to do, but they are using on poultry

14. 7. Food Additives
examples:
Salt
Na or Ca - inhibit mold
Sorbic acid - inhibit yeast/mold, used in cheese and fruit drinks

15. Benzoic acid/sodium benzoate - candied products
BHT/BHA - preserve fat in meat
Citric acid/tartaric acid - antioxidants (traps oxygen)

16. WHAT HAPPENS WHEN FOOD FREEZES??
Example: Tomato
the water in the tomato freezes and forms ice crystals which act like sharp pieces of glass and puncture cells, the slower the freezing the larger the crystals

17. WHAT IS FREEZER BURN?
it’s the loss of water from the frozen food