|
Abstract
The properties for measurement and calculation of
the dielectric properties (dielectric
constant, loss tangent,  ; and dielectric loss factor,  of materials by use
of the slotted coaxial line technique of van Hippel et al is discussed. Sample holders used are described. Teqnique for preparation of samples is
discussed. Dielectric properties were
determined for eleven commercial fats and oils, varying in character from
completely unsaturated vegetable oils to saturated animal fats. Dielectric measurements were made at 300,
1,000 and 3,000 megahertz (MHz) at
77ºF (25º C), 125º F, (51.6º C), and 180º F(82.2º C). The following characteristics of the fats
and oils are also reported: moisture, iodine values, solid-fat index, and GLC
determination of fatty-acid chain lengths.
Dielectric properties are reported as a function of temperature and of
frequency. No significant difference
was found among the eleven fats and oils on any given frequency or
temperature. Dielectric properties
were also determined for raw potato and potato chips. Measurements on raw potatoes were made at
77ºF (25º C), 125ºF, (51.6º C), and 180º F(82.2º C); and at frequencies of
300, 1,000 and 3,000 MHz. The
following characteristics of the raw potato and potato chips are also
reported; moisture, total lipids, total nitrogen and ash. Dielectric values are reported as a
function of frequency for the raw potatoes and as a function of frequency,
temperature and moisture content for the potato chips.
|