Analysis of aroma-active compounds in different wheat flour mill streams using dynamic headspace extraction and comprehensive two-dimensional gas chromatography-olfactometry-mass spectrometry

In order to study the composition and content of aroma compounds in different wheat flour mill streams, this study combined dynamic headspace sampling and comprehensive two-dimensional gas chromatography-olfactometry-mass spectrometry (DHS-GCxGC-O-MS), an external standard method corrected for internal standards, to identify and analyze the aroma-active compounds in six wheat flour mill streams based on odor activity values (OAVs). Ten 10 aroma-active compounds - hexanal, octanal, nonanal, decanal, (E)-2-nonenal, 2,3-pentanedione, 3-octen-2-one, 1-octen-3-ol, butanoic acid, and 2-acetyl-1-pyrroline - were detected across different mill streams. The total content of aroma compounds was the highest in mill stream 2M1I, followed by mill streams DD2, 1S1, 3M1II, 5M1II, and 5B1. Among the various aroma-active compounds, hexanal, nonanal, and 2-acetyl-1-pyrroline showed relatively high OAVs in flour mill streams 2M1I and 1S1 than in other flour mill streams. Thus, these two streams were found to have greater aroma compound intensity. By identifying the differences in aroma compound contents across different wheat flour mill streams, this study provides technical support for the development of wheat flour products with a strong aroma.