Freeze drying system for berries

Delicate structure and high moisture levels make it difficult to dry berries while remaining shape, flavour and nutrients. Loss of volatile compounds and acids can result in loss of aroma and flavours even when using gentle and low-impact drying methods such as lyophilisation.

Water adsorption with zeolite reactors to minimize loss of volatile molecules

Bucher Unipektins’ Zeodration system uses Zeolite reactors to selectively adsorb water molecules. Zeolite is crystallised clay with a pore diameter of 4 Angstroms (water molecules are 3 Angstroms). Its properties combined with polarity factors lead to a selective moisture trap, which under operating pressure conditions retains water only. Because of a very low partial pressure at the water adsorption, a maximum reduction of lost volatile molecules through the vacuum system is achieved.

Due to an integrated regeneration of Zeolite, full adsorption capacity is maintained and drying in the pressure range of 0.5–10 mbar is permitted. Most importantly, zeodration technology ensures that no change of product shape occurs in the process of adsorption. Bucher Zeodration systems have an adsorption capacity from 1 to 1000 kg/h water and are used for drying a wide range of products such as herbal and plant extracts, herbs and bacteria.


  • Residual moisture content of less than 0.5%
  • Best aroma retention
  • Batch or continuous process