Microwave Vacuum-Assisted Drying of Green Peas Using Heat Pump and Fluidized Bed: A Comparative Study Between Atmospheric Freeze Drying and Hot Air Convective Drying

作者：Zielinska M; Zapotoczny P^*; Alves Filho O; Eikevik T M; Blaszczak W

来源：Drying Technology, 2013, 31(6): 633-642.

DOI：10.1080/07373937.2012.751921

• Atmospheric freeze drying
• Fluidized bed
• Green peas
• Heat pump
• Hot air convective drying
• Microwave vacuum drying

This study investigates the performance of microwave vacuumassisted drying (MVD) of green peas using both fluidized bed and heat pump systems. A comparative study of heat pumpfluidized bed atmospheric freeze drying (HP-FB-AFD) and heat pumpfluidized bed hot air convective drying (HP-FB-HACD) was conducted. The initial drying rates of green peas were 0.04 and 0.121/min for HP-FB-AFD and HP-FB-HACD, respectively. Moisture diffusivity of green peas dried in HP-FB-HACD and HP-FB-AFD were 1.04x10(9) and 6.94x10(11)m(2)/s, respectively. HP-FB-AFD did not entail changes in the starch granules and preserved the sample size and shape with minimal shrinkage (20%), whereas HP-FB-HACD generated significant volumetric shrinkage (50%). HP-FB-AFD+MVD created a desirable porous inner structure of the final product. HP-FB-HACD+MVD significantly increased the hardness of the dried product and produced green peas with a compact structure and tightly packed cells. Neither HP-FB-AFD+MVD nor HP-FB-HACD+MVD significantly influenced the color of dried green peas. To respond to the current demand for high-quality products, the multistage combined HP-FB-AFD+MVD method is an interesting technique for green peas processing.

• 出版日期2013-4-26