1. August 2008 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 02471-21.2 June, 2002

2. August 2008 WHAT IS PRESERVATION? the treatment of food to keep it from spoiling

3. August 2008 PALATABLE an agreeable taste and/or texture

4. August 2008 CONDUCTION heating through direct contact example: roasting marshmallows, grilling hamburgers on stove top

5. August 2008 CONVECTION heating through water or air example: boiling water, using oven

6. August 2008 RADIATION heated through electromagnetic spectrum example: microwave

7. August 2008 PASTEURIZATION destroy pathogenic microorganisms but not spoilage microorganisms example: milk

8. August 2008 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. August 2008 2. Refrigeration - above freezing point 28 to 65 degrees F; short term storage 3. Freezing - actually freezing the water in the food

10. August 2008 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. August 2008 c. chemical drying add salt and sugar example: ham

12. August 2008 5. Fermentation - involves microorganisms (yeast, mold, bacteria) 2 ways: a. aerobic: with air b. anaerobic: without air

13. August 2008 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. August 2008 7. Food Additives examples: Salt Na or Ca - inhibit mold Sorbic acid - inhibit yeast/mold, used in cheese and fruit drinks

15. August 2008 Benzoic acid/sodium benzoate - candied products BHT/BHA - preserve fat in meat Citric acid/tartaric acid - antioxidants (traps oxygen)

16. August 2008 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. August 2008 WHAT IS FREEZER BURN? it’s the loss of water from the frozen food