Freund Group Introduces Water Activity Meter

The Freund Group seeks to expand its non-pharmaceutical product business and take on new challenges that enable it to contribute to improving the quality of health and life of people around the world.  Building solutions around these new challenges will establish a foundation for next generation growth.

One challenge that Freund Group is working on is related to the food product design and food safety.  Water activity affects food stability and therefore it must be brought to a suitable level at the conclusion of drying and maintained within an acceptable range of activity values during storage.

Water Activity (aw) in Foods – Definition

The water activity (aw) of a food is the ratio between the vapor pressure of the food itself, when in a completely undisturbed balance with the surrounding air media, and the vapor pressure of distilled water under identical conditions. The water activity increases with temperature. The moisture condition of a product can be measured as the equilibrium relative humidity (ERH) expressed in percentage or as the water activity expressed as a decimal. Most foods have a water activity above 0.95 and that will provide sufficient moisture to support the growth of bacteria, yeasts, and mold.  (U.S. Food & Drug)

Sorption Behavior

The bacterial cell can only transfer nutrients in and waste materials out through the cell wall. The materials, therefore, must be in soluble form to permeate the cell wall. A portion of the total water content present in food is strongly bound to specific sites and does not act as a solvent.

Below is a chart that outlines the water activity influence on the growth of microorganisms.  Water activity is closely related to quality of product containing water.

Water activity influence on the growth of microorganisms


Moisture Content

Water activity is important for quality control and development of products.

Measurement Device

The EZ-200 Water Activity Meter offers the following features:

  • Accurate measurement with a sensor less susceptible to alcohol
  • Easy replacement and calibration of the sensor (tool-free)
  • Control of sensor deterioration due to acids by placing a sensor protection filter (option)
  • Device storage of up to 100 measurements; USB memory available (CSV output)
Water Activity Meter_EZ-200

If interested in learning more about how the Freund Group can assist with measuring your water activity, please send inquiry to .

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