The Problem
Every food manufacturer has to ask: how long before my product
molds, gets soggy, goes stale, becomes rancid, cakes, clumps,
crystallizes-in short, becomes unacceptable? What can I do to
preserve and extend the shelf life of my product?
Moisture Sorption Isotherms
One key to answering that question lies in an energy status
picture of the product-its moisture sorption isotherm.
A moisture sorption isotherm is a graph showing how water activity
changes as water is adsorbed into and desorbed from a product held
at constant temperature.
Isotherms provide the specific data you need to:
Make component mixing models
Set QA/AC specifications
Define critical control points
Do packaging calculations
Predict the effects of temperature abuse
High-resolution isotherms can determine monolayer value and allow
formulation for maximum shelf life. They can even pinpoint
exact water activity values for caking and clumping, glass
transition, deliquescence, protective coating/layer permeability
and hygroscopicity.