Freezing rate ......slow freezing rates allow the growth of large ice crystals, leading to larger pores, to higher mass flow and thus shorter freeze drying time
Drying rate .......If drying proceeds too rapidly, the product melt, collapse, or be blown out of the container. This may cause degradation of the product.
Chamber The pressure..... both controls the mean of sublimation temperature and modifies the pressure transport parameters that influence the kinetics of vapour removing.............
Temperature ....Maintaining low temperatures during primary drying will reduce aroma losses.