Hot air and microwave drying of pomegranate (Punica granatum L.) arils

In this study, arils of Hicaz type pomegranates were dried by hot air and microwave drying technique. Drying behavior, shrinkage, rehydration, bulk density and color changes of the products were investigated. Hot air drying process was carried out at three different temperatures; 50, 60 and 70 °C at 1.0 m/s air velocity. Also, three microwave power levels (210, 350, and 490 W) were studied as another drying technique. Among the several models listed in literature, the Page drying model was appropriate for both convective and microwave drying of the pomegranate arils drying. Increasing drying temperature and power intensity shortened the drying time of arils. Rate of drying was higher when microwave (5.83 × 10−3 - 2.85 × 10−2) used compared to air drying process (1.52 × 10−4 - 1.70 × 10−3). It was observed that shrinkage of air dried samples was higher than microwave dried sample. Rate of rehydration of microwave dried aril samples was relatively faster than air dried samples, but not significant statistically. However, bulk density of air dried samples was higher than those of microwave dried sample.