Nonenzymatic Browning in Amorphous Food Models: Effects of Glass Transition and Water

Abstract

ABSTRACT: The effect of glass transition on nonenzymatic browning (NEB) rates of amorphous, L‐lysine, and D‐xylose containing maltodextrin (MD)‐ or polyvinylpyrrolidone (PVP)‐based food models, equilibrated into a w of 0.23, 0.33, or 0.44 was studied. Glass transition temperature, T g , was measured using DSC and NEB rates, followed spectrophotometrically. Use of citrate buffer as a pH regulator was evaluated. The NEB rates were higher in PVP than in MD models. Arrhenius plots showed nonlinearity in the vicinity of the T g . Increasing a w decreased T g , but did not affect NEB rates around the T g . The temperature difference (T ‐ T g ) was not a sufficient measure of material stability.