Method and apparatus for the accelerated adjustment of water activity of foods and other materials

An accelerated method of achieving a desired moisture content or water activity in a standard sample of biomaterial by increasing the difference between the relative humidity of the atmosphere within the headspace of a sealed equilibration chamber and that of the sample whose moisture content or water activity is to be adjusted comprising the steps of:

• (a) determining the initial water activity and the desired water activity of said sample and determining therefrom whether the sample is to be dehumidified or humidified;
• (b) placing said sample on a sample support in the headspace of said equilibration chamber;
• (c) establishing and maintaining in said headspace an atmosphere of either 100% relative humidity if the sample is to be humidified or approximately 0% relative humidity if the sample is to be dehumidified;
• (d) exposing said sample in said headspace to said atmosphere for a predetermined length of time to achieve said desired moisture content or water activity, said length of time having been predetermined by the use of a previously prepared standard moisture content/water activity versus time curve, said curve having been prepared using corresponding samples under the same conditions in the same equilibration chamber;
• and
• (e) removing said sample from said chamber at the conclusion of said predetermined length of time when said sample has not reached an equilibrium with the humidity in said atmosphere in said chamber.