as the measurement method may itself cause changes to the product, resulting in a variation in the obtained values. Recognizing the difficulties in measurement of food properties, and the lack of completeness of such information, several research programs have been in existence during the last two decades. In Europe, a multinational effort has been underway since 1978. The first project supported by COST (European Cooperation in the Field of Scientific and Technical Research), was titled COST 90 "The Effect of Processing on the Physical Properties of Foodstuffs". This and another project COST 90bis have considerably added to our knowledge of measurement methods and data on a number of physical properties. Two publications that summarize the work conducted under 1 2 these projects are Physical Properties of Foods and Physical Properties of Foods .