Experimental study about changeable pressure on vacuum freeze-drying of Argopecten irradians concentricus

The article follows the former study'The effects of the operational parameters on drying time and energy consumption during vacuum freeze-drying of Argopecten irradians concentricus'. But it is unsuitable for the complicated freeze-drying process, fixed heating temperature and constant pressure of chamber during the whole process. By the orthogonal experiment, this article mainly explores the effects of adjustable pressure on the time of freeze-drying to obtain the optimal parameters as follows: high pressure 60 Pa, low pressure 10 Pa, adjustable temperature 0℃. The results indicate that compared with the optimal constant pressure, the method of adjustable pressure shortens the time of freeze-drying 10% or so, optimal adjustable method shortens 20% or so.