Measuring Moisture Content & Water Activity

Both moisture content and water activity—the ratio of the water vapor pressure of a substance such as food to the water vapor pressure of pure water under the same conditions—are important in formulating products for safety and stability.

In his Processing column in the October 2009 issue of Food Technology , J. Peter Clark discussed the basics of water activity, so in this month’s Laboratory column I will not go into depth on the concept. Instead, I will focus on the methods and instruments avai…