Innovative technologies optimizing the production process of "Castagne del Prete": Impact on microstructure and volatile compounds

"Castagne del Prete" are traditional processed chestnuts from the Campania Region obtained through a treatment involving a drying, roasting and rehydration phase. The last one is a long, costly and non-standardized treatment that is therefore in need of improvement. In the present study, different technologies (heat treatment, steam and thermosonication) were evaluated to optimize the chestnuts rehydration phase. To this end, microstructure, thermal properties and volatile organic compounds (VOCs) of "Castagne del Prete" obtained by different rehydration methods were evaluated. Results highlighted that thermosonication strongly influenced the starch gelatinization process, responsible for the total destructuration and denaturation of the crystalline network. VOCs analysis showed that the samples rehydrated by thermosonication with chestnuts/water ratio 1:5 had a volatile compounds pattern very similar to the control sample obtained by classic rehydration method. In addition, the time for obtaining "Castagne del Prete" by using thermosonication (approx. 5 h) as rehydration treatment was significantly reduced in comparison to the classic method which took approximately 7 days. Thus, thermosonication emerged as the most promising technique among those investigated for the production of "Castagne del Prete", as it saves energy and time, while guaranteeing the flavor and structural characteristics of the finished products.