CATALYTIC INFRARED AND HOT AIR DEHYDRATION OF CARROT SLICES

摘要

This study investigated the drying and quality characteristics of carrot slices underrncatalytic infrared (CIR) and hot air (HA) heating. Carrot slices with thicknesses ofrn3, 5 and 7 mm were dried at temperatures of 60, 70 and 80C with both methods.rnCIR had higher drying rates, shorter drying times and greater effective diffusivitiesrnthan HA before the moisture contents reached the range of 16–30% on a wet basisrn(w.b.). The total drying times required by CIR to reach the final moisture contentrnwas 60% less than HA. The effective diffusivities were in the range of 2.38–rn10.30 × 10~(−9)m~2s~(−1) for CIR drying and 1.43–5.50 × 10~(−9)m~2s~(−1) for HA drying. Resultsrnrevealed that carrot slices dried with CIR, particularly at 60 and 70C, had betterrnrehydration characteristics than the samples dried with HA. Thickness had a significantrnimpact on overall color change of carrot slices. The obtained correlationrncoefficient (R2) and root mean square error values indicated that the Midilli modelrnwas the best for predicting the moisture ratio change kinetics of carrot slices forrnboth drying processes.