Microwave–osmotic–vacuum combination drying of mango cubes with maltodextrin moderated sucrose solution

Abstract

A microwave–osmotic–vacuum combination drying technique was used to evaluate the effect of processing factors such as temperature and concentration with 15% inclusion of maltodetrin (dextrose equivalent, DE 10) during the microwave osmotic drying under continuous medium spray flow (MWODS) and power level during finish microwave vacuum drying (MVD). Moisture loss (ML), solids gain (SG), ML/SG ratio, weight reduction (WR), bulk density (BD), rehydration capacity (RC), drying times, and quality parameters, total color difference (ΔE), texture (hardness and chewiness) were evaluated during the process to assess the product quality. Drying conditions were optimized to maximize ML, ML/SG, WR, BD, RC and minimize ΔE, hardness, chewiness, and drying times. Optimum levels were found at 58.5 °C temperature, 50.0% concentration, and 30 min contact time during MWODS and 20% initial power up to 50% moisture content and 10% final power level to the final moisture content of 20% (32 min). In addition to MVD, freeze drying, vacuum and air drying were also used for comparison for finish drying. Overall, the MWODS with maltodextrin moderated sucrose as solute and MVD for finished drying resulted in better product quality and remained closest to the freeze dried samples.

Keywords:

• Microwave
• drying
• osmotic
• vacuum
• combination drying
• quality
• optimization