Identification of volatile compounds contributing to pennycress aroma

Abstract

The volatile compounds inherent to wild-type pennycress seeds were determined using solvent-assisted flavour extraction (SAFE), combined with gas chromatography-olfactometry (GC-O) and aroma extraction dilution analysis (AEDA). In this research, twenty-nine aroma-active compounds were detected via GC-O. With the aid of gas chromatography–mass spectrometry (GC-MS), retention indices, aroma descriptors and standard chemical verification, ten volatile compounds were positively identified: 2,5−/2,6-dimethyl-3-methoxypyrazine (grassy), allyl isothiocyanate (mustard, horseradish, onion), hexanal (green), (E)-2-octenal (earthy), acetic acid (sour), (E)-2-nonenal (woody), 1-octanol (grassy), 1-nonanol (green), 2-methylbutanoic acid/3-methylbutanoic acid (cheesy) and phenethyl alcohol (rose-like). By matching odour descriptions, mass spectra and retention indices, seven additional volatile compounds were tentatively identified: 1-pentanol, octanal, (E)-2-penten-1-ol, (E)-2-heptenal, (Z)-3-hexen-1-ol, (E, E)-3,5-octadien-2-one and pentanoic acid. These results provide an aroma analysis of pennycress, which can be useful in providing direction for pennycress breeding programs or tailored processing steps to eliminate the undesirable aroma components limiting the use as a food ingredient.