1. Food Preservation: Overview of Methodologies
By Lauren Woodliff for the CTAE Resource Network

2. Drying Oldest known method; 12,000 B.C. Sun, Wind & Fire
Fire also used to dry fruits, vegetables & herbs
Modern day examples of dried preserved food:
Beef Jerky
Sun Dried Tomatoes
Sun and wind were found to naturally dry and preserve foods
Oldest known method; 12,000 B.C.
Fire also used to dry fruits, vegetables & herbs
Wild game, fish and early domesticated animal meat were also dried
Modern day examples of dried preserved food:
Beef Jerky
Sun Dried Tomatoes

3. Pickling & Fermenting Pickling
Preserve foods in vinegar or other organic acid
Lower pH inhibit bacteria and microorganisms
Fermenting
Helpful microorganisms lower pH
Can make food more nutritious
Examples:
Sauerkraut
Yogurt
Wine
Most Cheeses

4. Sugar reduces the water content Lower pH Cooked during the process
Jam & Jelly
Sugar reduces the water content
Lower pH
Cooked during the process
All of the above inhibit microorganism growth

5. Curing Curing: Salt reduces water content
The addition of Nitrites and Nitrates inhibit the bacteria Clostridium botulinum, which causes botulism
Smoked foods are also cured

6. Freezing & Refrigeration
Zero degrees Fahrenheit
Easiest, least time-consuming and most convenient method
Refrigeration
40 degrees Fahrenheit or below
Prolongs shelf life of food
Slows growth of most microorganisms but does not kill or inhibit growth
Food will eventually spoil

7. Canning Extreme heating Oxygen is driven out Creates a vacuum seal
Two methods:
Water Boiling Canning
Pressure Canning
The method that should be used depends on the type of food and its pH

8. Boiling Water Canning Foods with pH below 4.6, high acid foods
212 degrees Fahrenheit
Kills most food spoiling/illness causing bacteria and microorganisms except Clostridium botulinum (cause of Botulism)

9. Pressure Canning Foods with ph above 4.6, low acid foods
240 degrees Fahrenheit
Only pressure canning
can reach temperatures
this high
Kills the bacteria,
Clostridium botulinum

10. Summarize and Discuss
Why is it important to preserve food for later use, especially before modern day packaging and refrigeration?
Why is important to choose the right method for different foods?
What are some of the factors that determine what method to use?
Think about the food that you eat on a daily basis that have been preserved using the methods that have been discussed.