What exactly is Freeze Drying and Freeze-Dried Foods?

Freeze-drying is the process that removes moisture by freezing products and then utilising a vacuum to sublime the moisture leaving an almost 100% dry product. Now let’s dive in a little deeper!

The freeze-drying process is one of the best processes for preserving food items for a longer duration. The new technology allows solid food elements that contain certain moisture levels or have liquids levels that contain certain solid food elements to be dried to almost a point where the food mixture contains zero moisture levels. 

• The freeze-drying process involves a few steps which are to be performed in a particular order: 

1. The process begins by cooking the food with its authentic recipe. 

2. The Blast Freezer freezes the food mix to a temperature between – 30 C and – 40 C making the food mix fully frozen at an extremely low temperature. 

3. After the food has been frozen, The food is transferred to vacuum chambers or freeze-drying machines. In this machine, this food is heated at 0 degrees C for nearly around 8 to 10 hours. Surprisingly the nutritional value of each food item is intact. 

4. Moisture from the food is taken out by nearly 99.9% 

5. Later the dried food is packed into small packets. 

The entire process makes the food freeze-dried and can be stored for a really long time.  

• Is Freeze Dried food healthy?

Freeze-dried food is really no different than regular food! It simply doesn’t have moisture. 

While there is limited research specifically on freeze-drying technology, the research that has been completed shows that freeze-dried food retains an almost identical flavour, colour, texture and nutritional profile to non-freeze-dried food with some nutritional loss for water-soluble vitamins. 

When comparing freeze-dried to other preserved food, freeze-dried food most closely matches fresh food.

With the exception of certain vitamins, the nutrition profile is virtually unchanged. 

• Advantages of Freeze Drying Food

With freeze-drying, foods and liquids can be dried at low temperatures without damaging their physical structure. Freeze-dried foods don’t need to be refrigerated or preserved with chemicals and can be reconstituted quickly and easily by adding water.

Conventional drying methods also have a major disadvantage as the high temperatures used can cause chemical or physical changes. Changing the taste or texture of a food product could make it inedible or less palatable which would be very undesirable.