Drying of restructured chips made from the old stalks of Asparagus officinalis: impact of different drying methods

BACKGROUND: Old stalks of Asparagus officinalis, which account for one third of the total length of each spear, are always discarded as waste. To make full use of the resource, a kind of restructured Asparagus officinalis chip was made. The effects of pulse-spouted microwave-assisted vacuum drying (PSMVD), microwave-assisted vacuum drying (MVD) and vacuum drying (VD) on texture, color and other quality parameters of restructured chips were then studied to obtain high-quality dried chips. RESULTS: Results indicated that the drying time was significantly affected by drying methods, and PSMVD had much better drying uniformity than MVD. The expansion ratio and crispness of chips increased with increasing microwave power and vacuum degree. The browning reaction of samples in VD was more serious, which was confirmed by the results of color test and electronic nose. CONCLUSIONS: The PSMVD drying method showed much better drying uniformity than MVD. The dried chips obtained by PSMVD showed optimal quality and were more readily accepted by consumers. (c) 2015 Society of Chemical Industry