A box of whole grain crackers was sent in for testing. The product had a strong pungent odor. The customer complained of a petroleum taste and a burning sensation around mouth area. Another said it had a stale taste.
Ingredient list:
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GC-MS chromatogram overlay; Normal sample on bottom, complaint sample above it shows a huge increase in volatile breakdown products, mainly aliphatic aldehydes:
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ID of peaks in in bad sample; most are aldehydes up to C11 from fatty acid breakdown:
e.g. "C6 ALD" = hexanaldehyde; "C6 FA" = C6 (hexanoic) fatty acid
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Below are the n-aldehyde peaks and spectra in the sample extract, followed by n-aldehyde spectra at identical retention time from reference standard mix injection, and aldehyde reference spectra in NIST or Wiley library
Pentanal peak at 3.9 minutes:
Hexanal at 6.1 minutes:
Heptanal at 8.5 minutes:
Octanal at 10.8 minutes:
Nonanal at 12.9 minutes:
Decanal at 14.9 minutes:
Also, the earliest eluter butanal, at 2.5 minutes, on tail end of the solvent peak. The Inlet Purge Off time was shortened in order to see the very early eluters which usually wouldn't be seen by the time the solvent peak ends and the detector is turned on, These are not retained much by the 0.25 mm capillary column DB-5 phase, causing their peaks to co-elute and be very wide.
Misc: product info
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Additional info, perspective, analytical notes:
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