Abstract SCHIRACK, ANDRIANA VAIS. The Effect of Microwave ...

techniques enable the efficient stripping of compound with a high boiling point, and
reflect the flavor of oil samples to a greater degree than static headspace techniques
(Ulberth and Roubicek, 1993). A neutral, nonreactive gas is used to purge the
sample, and the volatiles are trapped using porous polymer, charcoal, liquid
nitrogen, or sub-ambient cooling (Waltking and Goetz, 1983). In a study by
Vercellotti et al. (1992), a sparging device combined with FID and FPD allowed
simultaneous detection of 18 typical active flavor compounds and 14 sulfur-
containing compounds in peanuts. A polymer adsorption method involving nitrogen
flow over peanut samples in a jacketed glass column to a series of Tenax traps was
used by Buckholz, Jr. et al. (1980b) to collect and quantitate headspace volatiles
from freshly roasted peanuts. The results approximated the same ratio of volatiles
perceived by human senses in the peanut samples. Although this method reduced
sample handling and allowed both a larger sample size and shorter extraction time
(4 hours), the method also resulted in partial loss of some of highly volatile
compounds. This was corrected by using three traps in a series (Buckholz Jr. et al.,
1980b).
An alternative to purge and trap is SPME (solid phase microextraction), which
is a volatile extraction method using no organic solvents and relatively low
temperatures via substituted siloxane coatings attached to a plastic fiber. The fiber
partitions molecules in liquid and air matrices (Pawliszyn, 2000). Modified SPME
methods have been used to analyze volatiles in microwave processing. For
example, Roberts and Pollien (1998) designed a method to quantitate aroma
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