Characterization of vacuum microwave, air and freeze dried carrot slices

Abstract

Vacuum microwave drying of carrot slices was compared to air drying and freeze drying on the basis of rehydration potential, color, density, nutritional value, and textural properties. Vacuum microwave dried (VMD) carrot slices had higher rehydration potential, higher α-carotene and vitamin C content, lower density, and softer texture than those prepared by air drying. Carrot slices that were air dried (AD) were darker, and had less red and yellow hues. Less color deterioration occurred when vacuum-microwave drying was applied. Although freeze drying of carrot slices yielded a product with improved rehydration potential, appearance, and nutrient retention, the VMD carrot slices were rated as equal to or better than freeze dried (FD) samples by a sensory panel for color, texture, flavor and overall preference, in both the dry and rehydrated state.