Characterisation of osmotically dehydrated papaya with further hot air drying and microwave vacuum drying

Papaya was subjected to osmotic dehydration (OD) prior to hot air drying (HA; 70 degrees C) and microwave vacuum drying (MVD; 3.75Wg1 and 13.3 kPa). An increase in immersion time in a sucrose solution [65/100g (w/w)] at 40 +/- 2 degrees C from 0 to 4h decreased moisture content from 7.5802 to 1.2215kg waterkg dry solid1. During HA and MVD, effective moisture diffusivity was in the range 7.09x108 to 9.13x108m2s1 and 2.85x106 to 3.50x106m2s1, respectively, depending on immersion time. The hue angle of HA samples was 0.830.91, whereas that of MVD samples was 48.5550.32. Both drying methods decreased springiness. Porosity was clearly observed in MVD samples. Rehydration rate was enhanced by increased immersion time and MVD (P0.05). From preference mapping, MVD samples were more preferable than HA samples. Moreover, MVD samples with 13h OD were more preferable than those with 4h OD.