Drying kinetics and effective moisture diffusivity of pomelo albedo under vacuum‐assisted microwave drying and its semi‐product

Abstract

The five different microwave power levels (800, 640, 480, 320, and 160 W) assisted with the vacuum of 40 kPa were investigated for the drying kinetics, effective moisture diffusivity and rehydration ratio of the dried pomelo albedo. The comparison of some product quality indicators after production and 6 months of storage was also taken place in this study. The higher microwave power levels provided the shorter drying times, the higher moisture diffusion and the drying rates. Drying time at 160 W needed more than 120 min while the rest needed less than 25 min to reach the moisture content below 8% (dry basis). By basing on χ 2 and root mean square error and R 2 , experimental drying data were best performed for the Page equations compared to other eight models (Diffusion approach, Two term exp, Henderson and Pabis, Lewis, Logarithmic, Vermar, Two modified compartment, Wang and Singh).The effective moisture diffusivity coefficient determined by Fick's second law was varied from 1.0 Â 10 À5 to 6.52 Â 10 À7 m 2 /s. The developed models describing the relationship between different drying parameters in this study can be used for optimizing the parameters in the drying process at a larger scale. The microwave power level of 480 or 640 W and the sample weight of 50 g were recommended for the drying of the pomelo albedo. Under these conditions, the dried albedo product possesses high quality. Most of the characteristic quality indicators changed insignificantly as compared after production and stored for 6 months at room temperature (25-28 C).

Comparison of water mobility and distribution in Dioscorea opposita Thunb. cv. Tiegun during hot‐air and microwave drying processes

“…The moisture ratio decreased more slowly at 180 W than at other powers. A similar trend was obtained in other food such as potato slices (Darvishi et al ., 2013) and pomelo albedo (Nguyen & Le, 2022). Higher microwave power can result in a larger difference in the vapour pressure between the inside and the outside of yam slices, thereby promoting water evaporation (Li et al ., 2018).…”

Effective moisture diffusivity prediction in two Portuguese fruit cultivars (Bravo de Esmolfe apple and Madeira banana) using drying kinetics data

“…This simplification is used very often to predicted D eff from drying kinetics data [ [39] , [40] , [41] , [42] , [43] , [44] ].…”