Implications of Non-Equilibrium State Glass Transitions on Carbohydrate Polymers

Abstract This chapter reviews the implications of the non-equilibrium state of amorphous carbohydrate polymers in the vicinity of the glass-transition temperature ( T g ). Particular emphasis has been made in the behavior of starch-based materials with low humidity contents. In order to approximate to the equilibrium state, amorphous starchy materials can undergo significant changes when they are annealed below or above the glass-transition temperature. Physical ageing and recrystallization processes have been discussed in detail, as well as their consequences on calorimetric and mechanical properties. Other aspects that are reviewed here include some rheological properties, relaxation times and plasticizing/antiplasticizing effects of water and other ingredients of starch-based food formulations.