Characterization of the key aroma compounds in roasted duck liver by means of aroma extract dilution analysis: Comparison with beef and pork livers

By application of the aroma extract dilution analysis (AEDA) on the volatile fraction isolated by solvent extraction and solvent-assisted flavour evaporation from roasted duck liver, thirty odour-active areas could be detected in the flavour dilution factor (FD) range of 16-2,048. The highest FD factors were found for 2-acetyl-1-pyrroline (roasty, popcorn-like), 2-acetyltetrahydropyridine (roasty), and 2-acetyl-2-thiazoline (roasty), followed by 2-furfurylthiol (roasty, coffee-like) and 3-methylthio(propanal) (cooked potato) with slightly lower FD factors of 1,024. Application of the AEDA on the volatiles isolated from roasted pork and beef livers revealed basically the same set of odorants in about the same range of FD factors in both livers. A main difference, however, was the comparatively low FD factor of 2-acetyltetrahydropyridine in beef and pork livers indicating that this roasty smelling odorant might be responsible for the difference detectable in the overall aroma of duck liver. In total, 15 odorants were identified for the first time in liver.