Drying kinetics and quality parameters of pumpkin slices dehydrated using different methods

摘要

Drying of pumpkin slices was carried out using convective, vacuum-microwave, vacuum and freeze drying methods. The aim of our study was to determine the drying shrinkage and bulk density, as well as to measure the colour and carotenoid content for the slices of 12 pumpkin cultivars. Another major objective was to establish the moisture content, specific density and cutting strength of the slices before dried, as well as the kinetics of their dehydration by the convective and vacuum-microwave methods. The application of the vacuum-microwave method has approximately tenfold shortened the time of pumpkin slice drying as compared to the convective method. In the hot air stream, the slices of the species Cucur-bita pepo were dehydrated faster than those of the species Cucurbita maxima. When use was made of the vacuum-microwave process, the slices of C. maxima dried at a faster rate. Each of the drying methods used was more effective than the convective method.