Effect of complementary microwave drying on three shapes of mango slices

The effect of complementary microwave drying on three different, osmotically predehydrated mango slices (oval, longitudinal and transversal) was investigated. Sugar gain, weight reduction and water loss were evaluated for the three shapes after osmotic dehydration. Surface response methodology was used to determine the effect of microwave drying time and microwave plate load on the osmotically dehydrated slices. The results showed a significant effect on the response variables: dissolved sugar content (°Bx) and slice surface final temperature. At temperatures greater than 100°C, thermal damage was present in all the shapes. The maximum weight loss (35-45%) without thermal damage was achieved for all the shapes at temperatures between 95 to 98°C. This favorable drying range was bounded with upper and lower linear regressions, then microwave drying times and microwave plate loads to reach this zone were determined. The transversal slice dried the most plate loads (170 to 500 g), in less drying time (268 to 600 s) and achieved a sugar concentration between 77 to 63 °Bx.