- CLEANING & BLENDING OF GREEN COFFEE
- ROASTING & GRINDING OF GREEN COFFEE
- CLARIFICATION SYSTEM
- AROMA RECOVERY CUM CONCENTRATION SYSTEM (ARC System)
- COFFEE CONCENTRATION
UNIQUE FEATURES OF INSTANT COFFEE PLANTS
UNIQUE SPRAY DRYER DESIGN ENSURES:
However, use of freeze dryer retains aroma, improves appearance and taste because freeze drying takes place at a low temperature which minimizes heat damage and retains volatile components (aroma). It also increases the shelf life of the dried product as compared to standard drying practices.
Freeze-drying involves dehydration of food products at low temperature and pressure. As a result only the moisture is removed, leaving the molecular structure intact. The end product is light in weight with least or no change in volume. Worldwide freeze-drying technology is considered as the ultimate amongst all other dehydration methods. Hence this technique is currently being used for the production of instant coffee.
In a freeze drying system, concentrated coffee (42-45%), is first freezed and then exposed to a low partial pressure (4.6 mmHg) of water vapour when ice sublimes directly to vapour leaving behind dried coffee.
Freeze drying is an expensive process in terms of capital, expenditure and operating cost but results in excellent product quality.
FREEZE DRYING OF COFFEE INVOLVES FOUR STEPS:
Freezing of the prefreezed coffee liquor at -50 °C in a blast freezer.
Sizing of the freezed coffee particles to a granular size of 3X3mm.
Sublimation of the ice in a vacuum freeze dryer (VFD) under vacuum (0.5 torr) and controlled temperature.
Gte Ltd has developed this technology successfully in their R&D laboratory, where a pilot plant has been set up for demonstration.
ADVANTAGES OF FREEZE DRYERS ARE: