A Two-Stage Vacuum Freeze and Convective Air Drying Method for Strawberries

Strawberries were dehydrated in a two-stage combination drying consisting of vacuum freeze drying (FD) followed by hot air drying (AD), and in a two-stage hybrid method involving FD and finish AD(FAD) to obtain dehydrated strawberries of high quality at reduced cost. Energy consumption and physicochemical properties of the FAD product were compared with single-stage AD and single-stage FD. The quality parameters of the products were also analyzed. It was found that the quality of combined FAD-dried products approximated that of single-stage FD. Hence, the proposed two-stage combination drying method is recommended for dehydration of strawberries to obtain a high-quality product at lower cost when compared with vacuum freeze drying alone.