Vacuum belt freeze dryer for fruits and vegetables

High-value products such as seasonal fruits are freeze-dried to maintain their original shape and quality regarding flavors, colors, and nutrients.

Continuous freeze-drying of high-value food products

Bucher Unipektins’ Dryband S is a dynamic belt dryer specially designed for freeze-drying delicate luxury solid food products such as coffee and tea, seasonal fruits and fish, and meats.

During the freezing process, drying water is removed from the product by sublimation under a vacuum. Quick-frozen products are fed onto the dryer’s belt through a vacuum-tight rotary valve, and drying is controlled through a combination of belt speed and plate temperatures. Solids are transported back and forward through the dryer to extend the residence time.

The drying belts feeding rate can range from 2 to 4,000 kg/h, and vacuum ranges from 1 to 50 m bar. The surfaces can achieve heating and cooling surfaces up to 325 m2 with a heating range between 20 to 180 °C. Freeze-dried fruits and vegetables such as corn and peas maintain their original shape and have a characteristic soft, crispy texture.

Benefits

  • Short drying time due to thin product layer
  • Low residual humidity
  • Fully automized WIP cleaning
  • Minimize loss of volatile oils and flavors