An improved simple gravimetric method for measurement of high water activities

Abstract
Summary: A previously reported gravimetric method for measurement of water activity (aw) has been simplified and improved, to determine aw in the range from about 0.700 to 0.999. Extrapolated aw values above 0.990 gave average underestimates of –0.001 aw units with the improved method. Comparative results on various dairy products were in good agreement with those found by a reference method (thermocouple psychrometer). The differences between the results provided by both methods were smaller for products with very high aw values than for products with high and intermediate aw values.