Glucose loss and maillard browning in solids as affected by porosity and collapse

The effects of porosity and collapse on the kinetics of glucose loss and br own pigment formation via the Maillard reaction were analyzed in solid low- moisture model food systems. Equimolar glucose and glycine were incorporate d into amorphous polyvinylpyrrolidones having different porosities, ranging from high porosity to totally collapsed. Samples were equilibrated and sto red in desiccators at water activity 0.33 or 0.44 and 25 degrees C. Glucose loss and brown pigment development were monitored for 3 months. Glucose lo ss rate constants were lower in collapsed systems compared to non-collapsed systems. The extent of porosity did not affect glucose loss rate constants . Collapse and porosity had minimal effects on the browning rate constants. Porosity and collapse affect chemical reactivity in low-moisture solids an d should be considered during product development and shelf-life testing.