DRYING SOME MEDICINAL AND AROMATIC PLANTS BY MICROWAVE

Ahmed, Taghreed H.

doi:10.21608/mjae.2018.95571

DRYING SOME MEDICINAL AND AROMATIC PLANTS BY MICROWAVE

Document Type : Original Article

Author

Taghreed H. Ahmed

Lecturer of Agric. Eng., Fac. of Agric., Zagazig Univ., Egypt

10.21608/mjae.2018.95571

Abstract

In this investigation, four different medicinal and aromatic plants chamomile, mint, sage and basil were dried by microwave under three different levels of power density (6.7, 10 and 20) W.g^-1 in order to study drying characteristics, energy consumption and drying efficiency for microwave drying. The experimented plants were dried to the final moisture content during (12,10 and 9) min for chamomile, while mint leaves took 9, 6 and 4 min, it took 9, 7 and 5 min for drying sage leaves and basil leaves took 14, 8 and 5 min for power density of (6.7, 10 and 20)W.g^-1 respectively. The minimum specific energy consumption and maximum drying efficiency were 4.96 MJ.kg^-1 H₂O and 45.52% were computed for drying sage samples using 6.7 W.g^-1 power density. Among the mathematical models investigated there are six thin layer drying models were fitted to the experimental moisture ratio data, the page and page I models satisfactorily described the drying behavior of basil leaves at 6.7 W.g^-1 and mint leaves at 10, 20 W.g^-1 with highest r² values but for the other treatments Newton model and Henderson and Pabis model were the best. The moisture diffusivity increased with microwave power density. The lowest values of effective moisture diffusivity were (5.03739×10^-8, 6.01782×10^-10, 1.72664×10^-9, 5.769×10^-10 m².s^-1) of chamomile, mint, sage, basil respectively at the lowest power density.

Main Subjects

Processing Engineering of Agricultural Products

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