1. Food Preservation Techniques Preservatives Added Canning Freezing Dehydration Irradiation Freeze-Drying Packaging Fermentation

2. Dehydration Helps to ensure microbes don’t live Decreases enzyme activity Decrease weight of food

3. Principles Add heat to remove water This could be through sun-drying Or by using special dehydrators

4. Dehydration Regardless, you need to control it! Still need some water content (15-20% of original moisture content) Otherwise flavour and nutritional content is decreased

5. Controlling Dehydration Air must be able to circulate Temperature must be monitored Must avoid bacteria and spoilage

6. Controlling & Pre-treatment… Define the following terms: –Case-Harden –Sulfiting –Sulfuring –Blanching (both steam & syrup blanching) –Sun Drying –Room Drying –Oven Drying –Dehydrators –Dehydro-Freezing