Bilgiç B., Baydar Atak G. , Sadıkoğlu H.

5TH INTERNATIONAL CONFERENCE ON ADVANCES IN MECHANICAL ENGINEERING , İstanbul, Turkey, 17 - 19 December 2019, pp.1362-1363

  • Publication Type: Conference Paper / Summary Text
  • City: İstanbul
  • Country: Turkey
  • Page Numbers: pp.1362-1363



Drying is a separation process that can be defined as the removal of water from a solid material. This process 

is used as a protection method of foods since ancient times because microorganisms that cause decay of foods do not 

grow or multiply without water. If the water content in food drops approximately below 10%, microorganisms can't 

work. At the same time, water content should usually drop below 5% in order to protect the taste, smell and 

substantiality. Like microorganisms, also, enzymes that cause chemical changes in foods do not perform without water. 

Because of these reasons, dried foods can be stored for a long time. In the literature, several methods used for drying 

of foods such as hot-air drying, freeze-drying, microwave drying, sun drying, etc. Freeze-drying in food is a relatively 

expensive drying method since the drying speed is very low compared to other drying methods and requires high 

energy usage. However, when compared with other drying methods, the highest quality product is obtained in freezedrying. In this study, drying methods are theoretically investigated and summarized. Freeze-drying was compared with 

the other drying methods in terms of the quality of foods that dried with different methods, advantages, and 

disadvantages of drying processes and the costs of these methods. In light of these comparisons, optimum operating 

conditions were determined for freeze-drying of foods.

Keywords: Drying, Freeze-Drying