Quality of restructured cookies made from old stalks of Asparagus officinalis using various drying methods

The restructured crisp cookies were made from the old stalks of Asparagus officinalis. Temperature distribution, expansion ratio, moisture content, and color were measured to evaluate the drying uniformity of the cookies by applying pulse-spouted microwave-assisted vacuum drying (PSMVD) and microwave-assisted vacuum drying (MVD). Besides, bulk density, expansion ratio, microstructure, and textural properties were used to compare the products' quality obtained by three different drying methods including vacuum drying, MVD, and PSMVD. Results showed that the products dried by PSMVD were more uniform compared to those samples dried by MVD. The pulse-spouted mode in drying chamber substantively improved the microwave-vacuum-dried products' quality, drying uniformity, and drying characteristics.