Food Drying Processes

Food Drying processes is a method to preserve foods. By the removal of water bacteria, mold or yeast cannot grow to decay the food.

Food can be removed by food hydration through classic evaporation by the sun, air, smoke, and electric dehydrators or through the modern freeze-drying process. The classic method has been used for thousands of years and allows limited long-term storage. Freeze drying provides foods that can be stored with oxygen adsorbers in dried containers for 10 to 20 years. They keep better the texture, flavor and nutritional values.

Freeze Drying Process

The process takes advantage of a physical property of water which is shown in a phase diagram.If water is cooled under reduced pressure below its triple point, the formed ice can be removed as a gas by a process that is called sublimation.

The freeze drying machines are using 3 steps:

1. Fast freezing to – 40F to form ice crystals
2. Low pressure and slight heating are used to sublime the water and remove it.
3. By raising again slightly temperature stronger boded water molecules are removed.

We are using a Harvest Right home freeze dryer, giving the link here.