Microstructure affects the rate of chemical, physical and color changes during storage of dried apple discs. http://dx.doi.org/10.1016/j.jfoodeng.2007.06.037

Abstract

Blanching, freezing and drying induce major changes in the physical properties of processed foods. Microstructural changes induced by these processes in applediscs were related to the degree and kinetics of browning and to fracture mechanics after drying and later storage at 70 °C under a wide range of relative humidity (RH). Blanched and unblanched applediscs were dehydrated by vacuum drying or freeze-drying to induce the formation of different structures, then equilibrated from 33% to 75% RH and stored at 70 °C in order to promote browning. Colorchanges on the surface of applediscs were analyzed non-invasively by image analysis using a computerized vision system. Pre-treatments and drying conditions modified the structural characteristics of applediscs, which in turn, changed sorption properties, texture hardness and browning development. Microstructural changes (e.g., loss of cellular integrity) promoted higher browning rates, the rate and degree of browning was analyzed.