Biochemical characterization of apple slices dried using low temperature and stored in modified atmosphere packaging

Apple slices (Pinova cv) dried at mild temperature (40 ºC), compared to 65 ºC dried slices, are enriched (up to about 50 %) in polyphenols (e.g., catechin, epicatechin, quercetin 3-glucoside, quercetin derivatives). Chemical (dipping solutions) and physical (packaging) treatments are key in controlling the enzymatic browning of dried apple slices and maintain their nutritional content. In the present study we investigated the effects of dipping and packaging on the physicochemical properties of dried apple slices. Specifically, apple slices dried at 40 oC were comparatively dipped in 1 % calcium citrate (CC) or 1% citric acid (CA) and stored in active modified atmosphere (a-MA) or in passive (p-MA) for 100 days. A mild drying approach combined with dipping in CC and a-MA preservation, produced high quality dried apple slices, both in terms of sensory characteristics and colour retention. Remarkably, upon this treatment, fruits exhibited an enhanced volatile profile that correlated with fresh and fruity apple notes.