Food processing extends the edible time frame of foods through various preservation methods like drying, salting, curing, fermentation, freezing, smoking, canning, pasteurization, refrigeration, and freezing. These techniques work by inhibiting the growth of microorganisms through moisture removal, salt or chemical addition, lowering the temperature, or changing the environment. Proper food safety involves identifying and controlling hazards like pathogenic bacteria at each stage of production using techniques like HACCP and ensuring foods do not remain in the temperature danger zone where bacteria proliferate rapidly.

1. Introduction to Food
Processing

2. Why process foods?
• Extend edible time frame -Preservation
• Make better tasting foods
• Make more varieties of food
• Convenience

3. Drying
• Extraction of moisture by sun, air, heat or
vacuum to inhibit the growth of molds,
bacteria and yeasts
– Name 3 dried foods

4. Salting
• The addition of salt or a brine solution to
foods to decrease the activity of molds,
bacteria and yeasts.
– Name 3 salted foods

5. Curing
• The addition of a chemical compound
(sodium nitrate or sodium nitrite) to food to
slow the growth of bacteria.
– Name 3 cured foods

6. Fermentation
• The use of special bacteria, molds or
yeasts to prevent spoilage by converting
the elements of food that spoil easily to
stable elements that act as preservatives.
– Name 3 fermented foods

7. Freeze Drying
• The freezing of food and the subsequent
removal of water from the frozen food
through the use of heat and a vacuum.

8. Smoking
• The addition of smoke and heat to
preserve food by the action of the
chemicals from the smoked wood and the
partial drying of the food.
– Name 3 smoked foods

9. Canning/Aseptic Packaging
• The packing of food in a container, sealing
the container and heating it to sterilize the
food.
– Name 3 canned foods

10. Pasteurization
• The heating of milk and other liquids
which reduces the number of disease-
producing bacteria.
– Name 3 pasteurized foods

11. Refrigeration
• The lowering of the temperature of food to
inhibit the growth of bacteria, molds and
yeasts.
– Name 3 refrigerated foods

12. Freezing
• The lowering of the temperature of food to
temperatures below 28 degrees F to stop
the growth of bacteria, yeasts and molds
and to kill parasites.
– Name 3 frozen foods

13. Food concentration
• Heating food until it boils and removing the
water or partially freezing food and
removing water in the form of ice crystals.
– Name 3 concentrated foods

14. Irradiation
• Passing energy through food to destroy
insects, fungi, or bacteria that cause
human disease or cause food to spoil.
– Name 3 irradiated foods

15. Food Safety
• HAACP: Hazard Analysis Critical Control
Point
• What safety risk is present for each food
– Pathogenic microorganisms
• Bacteria, viruses
– Spoilage microorganisms
• Fungi, bacteria
• What foods are at greatest risk for
contamination?

16. Most important qualities to control
• pH
– Bacteria thrive in a pH neutral environment (7)
– Items with pH above 8 tend to be very bitter &
toxic
– Foods with pHs below 6 tend to be tart or sour
1 7 14
Bacteria
Yeast/Fungi

17. Qualities to control
• Temperature
• 40 – 140°F = the temperature danger zone
– Rapid multiplication of microorganisms
• <40°F very slow growth
• <28°F – no growth – no death
• >140°F – death of microorgamisms

18. Qualities to Control
• Moisture content & Protein content
• Bacteria need a high moisture content
• Fungi can grow in lower moisture
– Dry foods won’t make you sick
– Dry foods do spoil
• Bacteria need protein, fungi less so
– Candy & carbohydrates may spoil but don’t
won’t make you sick

19. Food Deterioration
• Enzymes break down proteins over time
– Must deactivate enzymes before food can be
stored
– Heat destroys enzymes
• Fats and oils can oxidize in storage
– Gives off flavors
– Need airtight packaging or antioxidant
additives