The appearance of guaiacol in the apple juicewas confirmed by comparison
of the retention time and the fragmentation pattern to that of a
standard. Three major mass fragments for guaiacol occur at m/z 124
(M+), m/z 109 (the base ion, which represents loss of a methyl
group) and m/z 81. No guaiacol was detected in negative control apple juice samples (without A. acidoterrestris) during 14 days of
incubation.