ISBN 9783843957915

978-3-8439-5791-5, Reihe Lebensmittelchemie

Zhenli Xu
Key odorants in Houttuynia cordata rhizomes and leaves

119 Seiten, Dissertation Universität Hohenheim Stuttgart-Hohenheim (2026), Softcover, A5

Zusammenfassung / Abstract

Houttuynia cordata is an herbaceous perennial plant native to Asia and is well known for its characteristic fishy odor. This dissertation elucidates the molecular basis of the characteristic aroma of fresh Houttuynia cordata rhizomes and leaves. Volatile compounds were isolated using automated solvent-assisted flavor evaporation (aSAFE) and screened by comparative aroma extract dilution analysis (cAEDA). In total, 44 odorants were detected in the rhizomes and 41 in the leaves. The major odorants with flavor dilution (FD) factors ≥ 32 in at least one of the two plant samples were subsequently quantified, resulting in about 20 odorants with concentrations exceeding their odor threshold concentrations (OTCs). Aroma recombination and omission experiments identified 3-oxododecanal as the key odorant in the rhizomes and leaves and demonstrated that it is responsible for the characteristic fishy odor of Houttuynia cordata. To further investigate this compound, 3-oxododecanal was synthesized, purified, and characterized by chromatographic and spectroscopic techniques. GC-O and GC-MS detected only a single odor-active peak, indicating rapid tautomeric interconversion under chromatographic conditions, whereas NMR analysis and quantum chemical calculations revealed a predominance of its enol tautomer(s). Finally, tissue disruption experiments demonstrated that 3-oxododecanal is naturally present in intact plant tissue rather than being formed enzymatically after tissue damage. These findings provide new insights into the origin of the characteristic aroma of Houttuynia cordata and the chemical behavior of its key odorant.