The water activity of a food describes the energy status of water in a food, and hence its availability to act as a solvent and participate in chemical or biochemical reactions. Water activity, not water content, determines the lower limit of available water for microbial growth. Water activity also plays a role in the appearance, texture and smell of a food. Currently, the instruments used to measure water activity, differential scanning calorimeters and dynamic mechanical thermal analysis, are expensive and require technical expertise to operate. Decagon Devices, located in Pullman, WA, and known for their high quality biophysical instruments for food quality testing and environmental research, has developed a prototype instrument that will be easier to use, produce results quicker, and at lower cost.
Seaweeds are sources of food, fiber, unique chemicals and essential habitat for many organisms.
They have a long history of traditional uses but are also studied as a source of novel chemicals. Russell Tucker, Assistant Professor, Veterinary Clinical Sciences, Washington State University.