Effect of mixing and viscosity on rehydration of dry food particulates

Rehydration of dry food particulates is a rate-limiting step related to the nature and the history of the particulates and of utmost consumer importance. Developing the appropriate methodologies for studying the kinetics of water uptake during a short time, and identifying the pertinent variables affecting the process were the overall objectives. Water uptake of air- and freeze-dried carrots was monitored continuously. Open porosity increased water uptake significantly only when no starch was added to the medium. Water uptake was slightly affected by mixing speed and became significant with the increased viscosity of a 3% starch solution. The rehydration rate increased linearly with sample surface area.