Freeze dryer (Christ) : drying product without heating, 18 L/24h, 10 heating plate of 1 L.
1. Freezing of product
2. Primary desiccation (sublimation) : under vacuum, interstitial water contained in product changes from solid state (ice) to gas state
3. Secondary desiccation or final drying: under vacuum, this step allows to remove bound water, thus achieving residual humidity between 4% and 6%.
Two steps which play an important role in the quality of lyophilization process:
- Freezing : the aim is to lock water in the form of solid ice and not in form of small ice crystals;
- Vacuum: its quality is one of the most important part of lyophilization
- Preservation of organoleptic and nutritional quality in thermosensitive food products;
- Fast rehydration thanks to porous structure of powder;
- Preservation of biologic properties of molecules;
- Preservation of product until several years without modification;
- Require less place of storage.
Industrial applications :
- Organic products (protein, enzyme, microorganism….);
- Pharmaceutical and cosmetic products;
- Food products.