Microstructure and olfactory quality of apples de-hydrated by innovative technologies

The purpose of this study was to investigate on the of structural changes induced in apple texture upon dehydration with classical methods, as freeze-drying and convective-air drying, compared to apples dried through by packaging in innovative films based on natural polysaccharides. ESEM microscopy was used to detect structural changes. Our studies has shown that apples obtained by freeze drying had a more broken tissue texture, and that the composition of the films has an effect both on structure and re-hydration kinetics. Olfactory characteristics of the different dried apples were also investigated by using an electronic nose device and compared with tissue texture properties. Apples that have shown the most intact cell walls are those that better retain olfactory properties.