Comparison of the effect of microwave freeze drying and microwave vacuum drying upon the process and quality characteristics of potato/banana re-structured chips

摘要

This study investigated the drying characteristics of microwave freeze-drying (MFD)/microwave vacuum drying (MVD) of banana/potato restructured chips of varying proportion and microwave power. The results showed the MFD drying time had a maximum one-hour time difference between the samples treated with 2 W g~(-1) and 3 W g~(-1) microwave power; and the higher potato content samples have about 30 min predominance than low potato content samples in drying time and the total drying time of MVD samples was less than 60 min. For the rehydration ratio, MFD samples were far superior to the MVD samples. The MFD samples had more than 4.5 rehydration ratio. The data of the colour difference metre showed that 3 W g~(-1) microwave power would make samples slightly charred. The biggest differences between the MFD and MVD chips lie in their texture and shape; the hardness of MVD samples was 30.86 N, thrice higher than MFD samples.