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Energy Consumption, Density, and Rehydration Rate of Vacuum Microwave‐ and Hot‐Air Convection‐ Dehydrated Tomatoes
Author(s) -
Durance T.D.,
Wang J.H.
Publication year - 2002
Publication title -
journal of food science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.772
H-Index - 150
eISSN - 1750-3841
pISSN - 0022-1147
DOI - 10.1111/j.1365-2621.2002.tb09529.x
Subject(s) - dehydration , microwave , boiling , convection , chemistry , energy consumption , vacuum level , process (computing) , materials science , pulp and paper industry , meteorology , physics , electrical engineering , biochemistry , organic chemistry , quantum mechanics , computer science , engineering , operating system
ABSTRACT: Vacuum to lower boiling temperature and microwaves for energy transfer can provide very rapid dehydration at low temperatures. Tomato sections were dehydrated in a batch convection air dryer (AD), a 16 kW vacuum microwave (VM) dryer, or by 1 of 3 combination processes. Drying rate of the 100% VM process was 18 times that of the 100% AD process. Only a slight falling rate effect was noted in VM drying AD and VM in sequence allowed the operator to choose any process time between 0.8 and 14.75 h. In this instance the least energy consumption occurred in the 100% VM process. Lowest energy cost was found for the 70% AD / 30% VM process. These results are expected to be strongly dependent upon the scale and design of dryers. Tomatoes finish‐dried by VM exhibited a puffed structure associated with faster rehydration.