Principle
The method is based on the drying of food sample under reduced pressure (typically 25-
100 mmHg) in a vacuum oven for a specified time and temperature and their dried mass is
determined. The boiling point of water is reduced when it is placed under vacuum. As lower
temperatures can be used to remove the moisture (e.g. 70o
C instead of 100 o
C), so problems
associated with degradation of heat labile substances can be reduced. The products high in sugar
and fat (> 10%) can be determined by this method and also be used for all food samples by
drying under vacuum at 70-100 oC.