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

condensations between phenylacetaldehyde and aliphatic aldehydes, acetaldehyde,
isobutyraldehyde, or isovaleraldehyde, with the next step being dehydration.
Likewise, the headspace volatiles of roasted peanuts held in storage showed 2-
methyl pyrazine and 2,6-dimethyl pyrazine in the highest concentrations, of 11.19-
25.82 ng/mL headspace gas/10g peanuts (Warner et al., 1996).
Several pathways have been suggested for the formation of pyrazines,
including the reaction of sugars with amino acids, condensation and eventual
cleavage to form alkylpyrazines. Alternatively, at high temperatures, sugars may
first rearrange and cleave into smaller fragments, which then condense with amino
acids to form alkylpyrazines, and this latter is the more likely route in roasted foods
(Koehler and Odell, 1970).
However, pyrazines are not the only compounds which have been detected in
peanuts. In a study of roasted peanut volatiles, Mason et al. (1967) found
acetaldehyde, isobutyraldehyde, benzaldehyde, phenylacetaldehyde, as well as
tentative identification of 2-methylbutanal, 3-methylbutanal, and 3-methyl-2-
butanone using 2,4-dinitrophenylhydrazone derivatives. These aldehydes were
thought to arise by Strecker degradation of the corresponding amino acid. Ethyl
acetate, toluene, and N,N-dimethylformamide were also identified (Mason et al.,
1967). Other heterocyclic and sulfur compounds, such as phenols, ketones, esters,
alcohols, and hydrocarbons were found among the volatile components of roasted
peanuts by Walradt et al. (1971). Basha and Young (1996) separated peanut seed
proteins into fractions by gel filtration, heated these fractions, and tested the
resulting headspace gasses for flavor volatiles present in roasted peanuts, such as
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