Friedrich Drawert

Essential oil composition of three polyploids in the Achillea millefolium ‘complex’

Abstract Three members of the Achillea millefolium ‘complex’, the tetraploid variety ‘Proa’, a hexa- and an octaploid clone, were cultivated in a field experiment. The essential oil was obtained by steam distillation. A total of 149 constituents could be resolved by capillary gas chromatography. Eighty-two of the 118 compounds were identified by GC-MS analysis for the first time in yarrow. Qualitative and quantitative oil differences between the three cultivars are discussed.

Gaschromatographisch-massenspektrometrische Untersuchung flüchtiger Inhaltsstoffe des Weines

SummaryIn aroma-extracts of wines from various sorts and vintages 3-(methylthio)-propionic acid ethyl ester, acetic acid-3-(methylthio)-propyl ester, 3-(methylthio)-1-propanol and 3-(ethylthio)-1-propanol were gaschromatographically separated and determined by means of an attached flame photometric detector (FPD). In the valid functionA + const. · concentrationn,A means the FPD indicator reading at 390 nm,n was found asn + 1.89. According to vintage, sort and origin of the wines the concentrations of the aroma substances range as follows: 3-(methylthio)-1-propanol 145–520 μg/l, 3-(ethylthio)-1-propanol 11–68 μg/l and acetic acid-3-(methylthio)-propyl ester traces — 15 μg/l. 3-(Methylthio)-propionic acid ethyl ester was found to be present only in traces (< 6 μg/l). Additionally, 3-(methylthio)-propionic acid and 3-(methylthio)-propionic acid methyl ester were determined qualitatively. The chemical identies of the sulfur compounds were ascertained by means of a mass-spectrometer.ZusammenfassungIn Aromaextrakten aus Weinen verschiedener Sorten und Jahrgänge wurden 3-(Methylthio)-propionsäure-äthylester, Essigsäure-3-(methylthio)-propylester, 3-(Methylthio)-1-propanol und 3-(Äthylthio)-1-propanol gaschromatographisch getrennt und unter Verwendung eines Flammenphotometrischen Detektors (FPD) bestimmt. In der für die FPD-Anzeige (A.) bei 390 nm gültigen FunktionA + konst. · Konzentration wurden + 1,89 ermittelt. Die Konzentrationen der Aromastoffe liegen je nach Jahrgang, Sorte und Herkunft in folgenden Bereichen: 3-(Methylthio)-1-propanol 145–520 μg/l, 3-(Äthylthio)-1-propanol 11–68 μg/l und Essigsäure-3-(methylthio)-propylester Spuren −15 μg/l. 3-(Methylthio)-propionsäure-äthylester ist eine Spurenkomponente (< 6 μg/l). Qualtitativ wurden ferner 3-(Methylthio)-propionsäure und 3-(Methylthio)-propionsäure-methylester nachgewiesen. Die Identität der Schwefelverbindungen wurde massenspektrometrisch gesichert.

Gaschromatographisch-massenspektrometrische Untersuchung flüchtiger Inhaltsstoffe des Weines VI. Aromastoffe in Tokajer Trockenbeerenauslese (Aszu)-Weinen a) Neutralstoffe

SummaryThe aroma compounds of Tokaj aszu-wines (1963, 5-butt. and 1973, 6-butt.) have been enriched by liquid-liquid extraction (pentane-methylenchloride 2+1) and compared with the aroma substances of a magyarFurmint wine (1973). After the separation of the acids and after the fractionation of the aroma extracts on silicagel 119 aroma components have been identified in the neutral fractions by means of the combination gaschromatography —mass spectrometry. Concerning the volatile constituents relatively high concentrations of furfural, 5-methyl-furfural, acetoin, different acetals, the ethyl esters of keto-, hydroxy- and dicarbonic acids and the lack of terpenic compounds are characteristic of the aszu wines. Quantitative differences depending on the vintages and the conditions of storage have been determined; particularly the concentrations of the acetales depend on the age of the wines.ZusammenfassungDie Aromastoffe von Tokajer Trockenbeerenauslese (Aszu)-Weinen (Jahrgang 1963, 5-buttig und Jahrgang 1973, 6-buttig) wurden extraktiv (Pentan/Methylenchlorid: 2 + 1) angereichert und mit den Aromakomponenten eines ungarischen Furmint-Weines (Jahrgang 1973) verglichen. Nach Abtrennung der Säuren und Vorfraktionierung der Aromakonzentrate an Kieselgel konnten in den Neutralfraktionen 119 Aromakomponenten gaschromatographisch-massenspektrometrisch identifiziert werden. Die Trokkenbeerenauslese-Weine sind hinsichtlich der flüchtigen Bestandteile u. a. durch relativ hohe Konzentrationen an Furfural, 5-Methylfurfural, Acetoin, verschiedenen Acetalen und Äthylestern von Keto-, Hydroxy- und Dicarbonsäuren sowie durch das Fehlen von Aromakomponenten mit TerpenstrukturThe aroma compounds of Tokaj aszu-wines (1963, 5-butt. and 1973, 6-butt.) have been enriched by liquid-liquid extraction (pentane-methylenchloride 2 + 1) and compared with the aroma substances of a magyar Furmint wine (1973). After the separation of the acids and after the fractionation of the aroma extracts on silicagel 119 aroma components have been identified in the neutral fractions by means of the combination gaschromatography--mass spectrometry. Concerning the volatile constituents relatively high concentrations of furfural, 5-methyl-furfural, acetoin, different acetals, the ethyl esters of keto-, hydroxy- and dicarbonic acids and the lack of terpenic compounds are characteristic of the aszu wines. Quantitative differences depending on the vintages and the conditions of storage have been determined; particularly the concentrations of the acetales depend on the age of the wines.

Production of 4-decanolide by semicontinuous fermentation of Tyromyces sambuceus

SummaryTyromyces sambuceus was cultivated in a stirred tank reactor under semicontinuous conditions for 70 days. Over longer periods of time in submersion, values of 220 and 330 mg·L−1 of 4-decanolide could be maintained; after dispersion of the headspace mycelia, a single peak product concentration of 880 mg·L−1 was attained. The productivity was subject to large variations, peak values were 18 and 11 mg·L−1·h−1. Depending on the culture conditions, specific growth rates of up to 0.05 h−1 were reached.

Enantiomeric distribution and 13C/12C isotope ratio determination of γ-lactones: appropriate methods for the difterentiation between natural and non-natural flavours?

Abstract The quantitative and enantiomeric distribution of γ-lactones in certain fruits (strawberry, raspberry, pineapple, passion fruit, plum and coconut) compared with corresponding fruit concentrates and beverages was determined by multi-dimensional gas chromatography mass spectometry with an achiral-chiral column combination. It was found that significant variations in enantiomeric excess values of γ-lactones due to varieties and processing influences can occur. On-line multidimensional gas chromatographic-isotope ratio mass spectrometric 13C/12Cisotope ratio measurements of γ-decalactone in vinous beverages and references (synthetic and microbial) were performed, in order to establish how far enantiomeric data in combination with additional δ13c values can serve as a basis for the validation of the genuineness of flavours and flavoured products.

Determination of sensorial active trace compounds by multi-dimensional gas chromatography combined with different enrichment techniques

Abstract Gas chromatographic equipment and appropriate procedures are described for the identification and determination of sensorial active compounds in complex mixtures. Different sampling systems (liquid injection, thermal desorption, dynamic headspace) were integrated in a single double-oven gas chromatograph, additionally allowing multi-dimensional separation, detection by simultaneous sniffing-mass spectrometric monitoring or micro-preparative enrichment of capillary effluents. The modular construction easily adapts to the diverse requirements of sample analysis without great modifications. The versatility and flexibility of such a combination are illustrated with different applications.

Über die Biosynthese von Aromastoffen durch Mikroorganismen

Using methionine as single nitrogen source 3-(methylthio)-1-propanol, 3-(methylthio)-propanal, 3-(methylthio)-propylacetate and 2-methylthiophan-3-one were formed in anaerobic model fermentations by Saccharomyces cerebisiae. The sulphur compounds were enriched by liquid-liquid extraction and detected by a selective flame photometric detector (FPD). The identities of the components were confirmed by mass spectrometry. It could be shown by quantitative determiniations that methionine was metabolized with 56--61% to 3-(methylthio)=1-propanol, when it was given to the medium in concentrations from 10 to 100 mg/1. 3-(methylthio)-propylacetuate, 3-(methylthio)-propanal, and 2-methylthiophan-3-one only could be detected in traces.SummaryUsing methionine as single nitrogen source 3-(methylthio)-1-propanol, 3-(methylthio)-propanal, 3-(methylthio)-propylacetate and 2-methylthiophan-3-one were formed in anaerobic model fermentations bySaccharomyces cerevisiae. The sulphur compounds were enriched by liquid-liquid extraction and detected by a selective flame photometric detector (FPD). The identities of the components were confirmed by mass spectrometry. It could be shown by quantitative determinations that methionine was metabolized with 56–61% to 3-(methylthio)-1-propanol, when it was given to the medium in concentrations from 10 to 100 mg/l. 3-(methylthio)-propylacetate, 3-(methylthio)-propanal, and 2-methylthiophan-3-one only could be detected in traces.ZusammenfassungIn Modellgärversuchen unter anaeroben Bedingungen mit Methionin als einziger Stickstoffquelle wurden vonSaccharomyces cerevisiae 3-(Methylthio)-l-propanol, 3-(Methylthio)-1-propanal, Essigsäure-3-(methyl-thio)-propylester und 2-Methylthiophan-3-on gebildet. Die Schwefelverbindungen sind durch Flüssig-Flüssig-Extraktion angereichert und selektiv mit einem Flammenfarben-Detektor (FPD) nachgewiesen worden. Die Identität der Komponenten wurde massenspektrometrisch gesichert. Quantitative Auswertungen ergaben, daß Methionin bei einem Zusatz im Bereich von 10–100 mg/l zum Gärsubstrat zu 56–61 % zu 3-(Methylthio)-1-propanol umgesetzt wurde. 3-(Methylthio)-propanal, Essigsäure-3-(methylthio)-propylester und 2-Methylthiophan-3-on waren nur in Spuren nachweisbar.

The C6-aldehyde-forming system in Agropyron repens

Abstract A vigorous formation of the volatile C 6 compounds typical of plant lipoxygenase/hydroperoxide lyase systems ( n -hexanal and hexenals) was observed in mechanically disrupted tissue of quick grass ( Agropyron repens ). Evidence for the precursor properties of linolenic acid and for the primary main cleavage product ( Z )-3-hexenal was obtained from time-course studies. Both the lipoxygenase and the hydroperoxide lyase activities occur in a pellet sedimenting at 15 000 × g . The relative proportions of 13- to 9-hydroperoxi-( E , Z )-10,12-octadecadienoic acids were 81 to 19 under the conditions used. The enantiomeric composition of the 13-hydroperoxide, the sole substrate for the lyase, was approx. 74 to 26 (13 S to 13 R ) and remained unchanged during prolonged incubation. The contribution of lytic activities to the formation of 1-penten-3-ol is suggested. The limited activity of the hexenal-forming system was neither caused by the carbonyls themselves nor by a hydroperoxide deficiency, and the inactivation followed third-order reaction kinetics.

Über die quantitative Zusammensetzung natürlicher und technologisch veränderter Aromen

SummaryPowders of celery tubers were prepared by mechanical comminution followed by enzymatic maceration with Rohament P resp. enzymatic liquefaction with a mixture of Rohament P and cellulase. The neutral volatile constituents of the drum dried, resp. freeze-dried powders, were enriched by solvent extraction, purified on silica gel columns and investigated by gas chromatography and gas chromatography coupled with mass spectrometry. The original aroma composition of fresh celery tubers (following inactivation of endogenous enzymes with methanol) was analyzed under identical conditions as for the powders. Quantitative comparison of the results showed that the concentration of most of the volatile compounds and also the aromatically valuable phthalides were drastically reduced by drum-drying. After freeze-drying the volatiles were present at much higher concentrations and about half of the phthalides were still present.Mechanical and enzymatic comminution of celery tubers followed by processing to dry products results in a significant decrease of the aroma content.ZusammenfassungSellerieknollen wurden nach mechanischer Zerkleinerung mit Hilfe von Rohament P enzymatisch maceriert bzw. mit einem Gemisch von Rohament P und Cellulase enzymatisch verflüssigt. Das Macerat und das Solubilisat wurden durch Walzen-und Gefriertrocknung zu Pulvern weiterverarbeitet. Die neutralen flüchtigen Bestandteile der Pulver wurden nach extraktiver Anreicherung und Reinigung über Kieselgelsäulen mittels Gaschromatographie und Gaschromatographie/Massenspektrometrie-Kopplung untersucht. Zur Bestimmung der originären Aromastoffzusammensetzung von frischer Sellerie sind die Knollen (Enzyminhibierung mit Methanol) unter identischen Bedingungen wie die Pulver aufgearbeitet worden. Quantitative Bestimmungen ergaben, daß im walzengetrockneten Pulver die Konzentrationen der Mehrzahl der flüchtigen Verbindungen sowie der wertgebenden Phthalide im Vergleich zum frischen Material drastisch reduziert wurden. Nach Gefriertrocknung waren die leichtflüchtigen Verbindungen noch in hohen Konzentrationen vorhanden und die Summe der Phthalide noch etwa zur Hälfte erhalten. Der durch die enzymatische Vorbehandlung bewirkte intensive Aufschluß des pflanzlichen Materials hatte bei Weiterverarbeitung zu Trockenprodukten eine deutliche Verminderung der Aromagehalte zur Folge.

Identifizierung von 3,7-Dimethyl-1,5,7-octatrien-3-ol als flüchtige Komponente des Trauben- und Weinaromas

SummaryAnother monoterpen alcohol, 3,7-Dimethyl-1,5,7-octatrien-3-ol (Ho-trienol) has been identified by means of the combination gaschromatography-mass-spectrometry in aroma extracts obtained from grapes and wines of the varietiesRiesling, Traminer, Ruländer, Müller-Thurgau, Scheurebe, Optima andRieslaner. The concentration of the aroma component depends on the varieties. Aromatic varieties show the highest values.ZusammenfassungIn Aromaextrakten aus Weintrauben und Weinen der SortenRiesling, Traminer, Ruländer, Müller-Thurgau, Scheurebe, Optima undRieslaner wurde ein weiterer Terpenalkohol gaschromatographisch-massenspektrometrisch als 3,7-Dimethyl-1,5,7-octatrien-3-ol (Hotrienol) identifiziert. Die Verbindung liegt sortenabhängig in unterschiedlicher Konzentration vor, wobei in aromabetonten Sorten die höchsten Gehalte gefunden wurden.