Dr. Elliot: Dehydrated vs. Freeze Dried Treats
With the abundance of animal treats appearing on store shelves, purchasing can be a daunting task. We are going to explore the differences between these two different approaches and the benefits of each.
Food drying, also called food dehydration, is the process of removing water from food, thus inhibiting the growth of microorganisms (enzymes) and bacteria by the circulation of hot, dry air through the food. Some companies utilize the sun and wind to dry the product and prevent spoilage which has been practiced since ancient times. Water is removed by evaporation (air drying, sun drying, smoking or wind drying).
Benefits of Dehydrated Food:
- No need to refrigerate
- Easy to store
- Lasts a long time
- Can have a smoked scent
- Elimination of pathogens
- What does dehydrated food look like?
- The usual colorization can be shades darker.
Process of Dehydrating Food:
The food is put on trays and placed in a rotating rack system in an oven. Heat is brought up to 145 degrees with circulating air exhausts. Many of the nutrients are destroyed, but this is something you don't need to worry about. The lower the temperature, the longer the drying time. Temperatures that are too high can cause hardened food. The hotter the temperature-the shorter the time for water removal.
Freeze Dried Food
Freeze-drying is a dehydration process used to freeze material and then reducing the surrounding pressure and adding enough heat to allow the frozen water in the material to change directly from the solid phase to the gas phase. Usually, the freezing temperatures are between −50 C and -80 C. Freeze-drying is used to preserve food and make it very lightweight which eliminates costly freight charges and also lengthens shelf storage. A properly sealed bag that prevents moisture stored at room temperature can be stored for years. The low water content eliminates the growth of microorganisms and decaying enzymes. Freeze–drying will keep products in a more natural state than heat dehydration. The natural flavor and nutritional content will not be altered. Freeze-dried products can be easily rehydrated.