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

was also observed. The addition of phenylacetaldehyde caused a green/plant-like
note, while the addition of guaiacol gave a darker roast character to the model as
compared to the control. 2,6-dimethylpyrazine, although adding a sweet, caramel
note at lower concentrations, became perceived as a sweet and rotten aroma at
higher concentrations. In the tasting models, phenylacetaldehyde added a
green/plant-like note at low concentrations, but created a stale/cardboardy character
at higher concentrations. Guaiacol added astringency, bitterness, and more ashy
and woody character to the flavor. 2,6-dimethylpyrazine added rotten notes to the
flavor, and also contributed to the perception of dark roast flavor. A combination of
these three compounds at their respective concentrations found in microwave
blanched peanuts created an aroma profile high in dark roast character, with more
astringency and tongue and throat burn, and less impact of positive characteristics
such as roasted peanutty attribute. The panel agreed that the combination of
phenylacetaldehyde, guaiacol, and 2,6-dimethylpyrazine each at a concentration of
one standard deviation above the average concentration found in the microwave-
blanched samples appeared to most closely mimic the off-flavor in microwave-
blanched peanuts.
The unique characters of these three compounds combine to form an off-
flavor which is difficult to define. Further work must be conducted to clarify the role
of 2,6-dimethylpyrazine. However, it appears that guaiacol contributes to the dark
roast/burnt flavor perceived in the microwave samples, and phenylacetaldehyde is
responsible for a green and cardboardy note which could be perceived as
stale/floral. In the future, these compounds could be used as chemical anchors for
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