What means freeze drying? Picture of phase diagram of water for hot air drying, evaporation and sublimation $($freeze drying$)$ with pressure and temperature for phase diagram of water? Which advantages and disadvantages hat freeze drying compare to hot air drying? How can we transfer heat inside the freeze dryer $(3$ methods$)?$which factors affect the drying time during freeze drying?

Explain the principle of freeze concentration $($effect of crystal size, methods for separation of crystal from concentrate,? Why is important for freeze concentration very slow freezing rate?how high can be liquid food concentrated using freeze concentration? How much energy will be used for removing $1kg$ water from juice using evaporation, freeze concentration and reverse osmosis methods?