Impacts of Explosion Puffing Drying Combined with Hot-Air and Freeze Drying on the Quality of Papaya Chips

Effects of two combination drying methods as well as two single drying methods on the quality of papaya chips were studied. The longest drying time was found in freeze drying (FD), while the shortest drying time was found in hot-air-explosion puffing drying (HA-EPD). The papaya chips dried by FD exhibited the lowest shrinkage, while the highest shrinkage was found in the hot-air drying (HAD) dried sample. The lowest and highest total color differences (△E) were found in the FD and FD-EPD. The FD dehydrated papaya chips showed the highest retention of ascorbic acid and total carotenoids. The fastest rehydration rate was also observed in samples dried by FD. The worst rehydration capacity was found in FD-EPD, which related to the collapsed porous microstructure. Papaya chips prepared by FD-EPD showed crispier texture, which were in line with their expanded porous microstructures. In conclusion, the application of combining with EPD may improve the retention of nutrition of papaya.