##  [Water Activity](/index.php/water-activity) 

  ##  [Water Activity](https://commerce.quantumdictionary.io/water-activity-0) 

  

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**Commerce, Trade & Industry Dictionary**

 







 

 

 

 



 

 

 

 

Definition

A dimensionless measure of the chemical potential of water in a product defined as the ratio of the vapor pressure of water in the product to the vapor pressure of pure water at the same temperature; it quantifies the fraction of water that is thermodynamically available to participate in microbial growth and water‑dependent chemical reactions.