Novasina

Water activity is a measure of the availability of the energy of “free” water and must not be mixed up with water content (g water / g substrate). The water activity is indicated with the so-called aW value and ranges between 0 (absolute dryness) and 1 (condensing moisture).  Only this part actively participates in the exchange with the ambient moisture and is of great importance with regard to the microbiological durability or the biological functions of the microorganisms.  The “free” water in products is partly responsible for the growth of undesirable organisms such as bacteria or fungi, which produce “toxin” or other harmful substances and has also a significant influence on the chemical behaviour of food, cosmetic, pharma and other products.