A gas‐chromatographic separation of cocoa aroma, followed by infra‐red and mass‐spectrometric identification, has yielded, besides 22 of the 91 previously described constituents, 35 new substances (8 aliphatic, 1 alicyclic, 7 aromatic, 9 o‐heterocyclic, 4 pyrrolic, and 6 pyrazinic).

A gas‐chromatographic investigation of coffee aroma has revealed, besides 34 known components, the presence of 4 new substances: 2,3‐dimethylpyrazine, γ‐buty‐rolactone, O‐acetylacetol and hexane‐2,3‐dione. The fragmentation pattern of 2‐Methyl‐tetrahydrofuran‐3‐one, a known component of coffee aroma, has been determined by means of high resolution mass spectrography.

Trans‐2‐penten‐1‐ol, 1‐ethyl‐2‐formyl‐pyrrole, 2‐trans, 4‐cis‐heptadienal, phenyl‐acetonitrile, methyl benzoate, 2‐phenyl‐but‐2‐enal and the lactone of 2,6,6‐trimethyl‐2‐hydroxy‐cyclohexylidene acetic acid have been separated from black tea aroma by gas‐liquid chromatography, and identified by infra‐red and mass spectrometry.

(5 I11 69) Sumnzary. A gas-chromatographic investigation of tomato aroma has revealed 46 components of which 32 are new. The isolation and identification of 2-isobutyl-thiazole, substance for the first time found in a natural aroma, are given in detail. Le tableau Cnunikre tous les composCs que nous avons trouv6s au cours de notre recherche ; ceux qui sont nouveaux sont en italique. Parmi ceux-ci, seul l'isobutyl-2-thiazole n'a pas encore CtC, i notre connaissance, identifiC dans un ar6me naturel; nous dCcrivons son isolement et son identification dans la partie exPCrimentale. Les mkcanismes de fragmentation sous inipact Clectronique de cette substance ont CtC explicit& apr&s mesure exacte de la masse des ions i un pouvoir de rksolution de 10000 : on observe 1'Climination d'un groupement mCthyle (m/e 126) ainsi qu'une fragmentation en deux Ctapes selon le schkma suivant.

A gas‐chromatographic investigation of black tea aroma has revealed, besides 19 known components, the presence of 4 new substances: 1‐penten‐3‐ol, trans‐2‐hexen‐1‐ol, α‐terpineol and β‐ionone. The fragmentation pattern of 1‐penten‐3‐ol has been determined by means of high resolution mass spectrography.