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Microwave Drying (microwave + drying)

Distribution by Scientific Domains
Chemistry100%

Selected Abstracts

A MODEL FOR TEMPERATURE AND MOISTURE DISTRIBUTION DURING CONTINUOUS MICROWAVE DRYING,

JOURNAL OF FOOD PROCESS ENGINEERING, Issue 1 2005
D. BOLDOR
ABSTRACT A heat and mass transfer model of continuous drying of farmer stock (in-shell, uncured) peanuts (Arachis hypogaea L.) in a planar microwave applicator was developed and investigated. Transport phenomena equations previously developed for batch-type microwave drying were successfully adapted to account for the spatial variation of the electric field inside the applicator. The theoretical equations developed, together with experimental methods, were used to determine the effect of microwave power level and dielectric properties on the temperature profiles and reduction in peanuts' moisture content (mc). The temperature profiles from the solution of these equations matched the experimental ones determined using fiber optic temperature probes inserted into drying peanut pods. An exact theoretical determination of mc reduction during microwave drying was not possible due to the dependence of dielectric properties on mc. The surface temperature distribution of the peanut bed measured using infrared pyrometry was well correlated with internal temperature profiles. [source]

Studies on different combined microwave drying of carrot pieces

INTERNATIONAL JOURNAL OF FOOD SCIENCE & TECHNOLOGY, Issue 10 2010
Wei-Qiang Yan
Summary Three different combined microwave (MW) drying methods were compared, namely microwave-assisted vacuum drying (MWVD), microwave-assisted freeze drying (MWFD), microwave-enhanced spouted bed drying (MWSD), in terms of drying rate, drying uniformity, product colour, rehydration ratio, retention of , - carotene and vitamin C, and energy consumption. The drying rate of MWVD and MWSD were much faster than that of MWFD. The largest drying rate was obtained in MWSD with 3.5 W g,1. In general, the colour of MWSD products was very uniform. Rehydration ratio of MWFD carrot pieces was almost the same as the freeze-dried (FD) products and better than MWVD and MWSD products. In addition, the highest retention of carotene and vitamin C was observed in MWFD carrot pieces. No significant differences were observed in carotene and vitamin C between MWVD and MWSD products. However, the energy consumption in MWFD was the highest. [source]

A MODEL FOR TEMPERATURE AND MOISTURE DISTRIBUTION DURING CONTINUOUS MICROWAVE DRYING,

JOURNAL OF FOOD PROCESS ENGINEERING, Issue 1 2005
D. BOLDOR
ABSTRACT A heat and mass transfer model of continuous drying of farmer stock (in-shell, uncured) peanuts (Arachis hypogaea L.) in a planar microwave applicator was developed and investigated. Transport phenomena equations previously developed for batch-type microwave drying were successfully adapted to account for the spatial variation of the electric field inside the applicator. The theoretical equations developed, together with experimental methods, were used to determine the effect of microwave power level and dielectric properties on the temperature profiles and reduction in peanuts' moisture content (mc). The temperature profiles from the solution of these equations matched the experimental ones determined using fiber optic temperature probes inserted into drying peanut pods. An exact theoretical determination of mc reduction during microwave drying was not possible due to the dependence of dielectric properties on mc. The surface temperature distribution of the peanut bed measured using infrared pyrometry was well correlated with internal temperature profiles. [source]