Premium
Comparison of constitutive wheat bran tissues by dielectric spectroscopy and effect of their moisture content
Author(s) -
Antoine Carole,
Castellon Jerome,
Toureille Alain,
Rouau Xavier,
Dissado Len
Publication year - 2004
Publication title -
polymer international
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.592
H-Index - 105
eISSN - 1097-0126
pISSN - 0959-8103
DOI - 10.1002/pi.1649
Subject(s) - aleurone , bran , dielectric , dielectric spectroscopy , capacitance , water content , capacitive sensing , materials science , sorption , moisture , chemistry , analytical chemistry (journal) , electrical resistivity and conductivity , composite material , chromatography , organic chemistry , electrode , electrical engineering , optoelectronics , enzyme , raw material , geotechnical engineering , adsorption , engineering , electrochemistry
The dielectric properties of hand‐isolated wheat bran tissues (outer pericarp, intermediate and aleurone layers) were studied at 58 % and 75 % RH between 0.001 and 1E10 + 6 Hz. The measured values of the real and imaginary parts of bran tissue capacitances were modelled using an electrical circuit consisting of a constant phase angle component (CPA), a Warburg impedance and a parallel capacitance. The theoretical data from the equivalent circuit are in close agreement with the experimental values and allowed us to characterize the dielectric properties of the tissue. These results showed that the aleurone layer was the most capacitive tissue even though the outer pericarp exhibited the highest resistivity. Finally, tissue moisture contents were deduced from isotherm sorption measurements for a range of RH, and the water effect on their dielectric properties was analyzed. Copyright © 2004 Society of Chemical Industry