Sweetness and bitterness can be regarded as mediators of vegetable preferences and intake, thus playing a prominent role in quality assessment. Sugars and saponins are known to cause sweet and bitter perception in asparagus. In the present investigation a trained, quantitative-descriptive sensory panel was used to assess various asparagus cultivars with known contents of sugars and saponins. Therefore, six asparagus cultivars, representing the range of cultivars used in commercial white asparagus production in Germany were selected. Material was harvested at two different dates and analysed for sugar and saponin contents. The contents of six individual saponins differed within cultivars and also between the harvest dates, whereas no differences of the sugar concentrations were found. Principal component analysis (PCA) allowed to identify the sources of sensory differences between samples, explaining 62 % of all variation: sweetness, bitterness and pungency. It could be shown, that only two of the investigated saponins were related to bitterness and sweetness perception.

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Das Spektrum ausgewählter Aminosäuren ist hinsichtlich der Ausbildung eines fleischartigen Geschmackseindruckes bei der thermischen Reaktion mit Glucose untersucht worden. Die reinen Aminosäuren reagierten — wäßrigen Milieu einzeln und in Mischungen, die nach statistischen Versuchsplänen zusammengestellt waren, zu Produkten, die sensorisch und instrumentalanalytisch charakterisiert wurden. Zielgröße der Optimierung der Aminosäuren nach Art und Menge war der sensorische Eindruck. Im Ergebnis konnten die Einflüsse der einzelnen Aminosäuren, optimale Versuchsparameter und eine optimale Zusammensetzung ermittelt werden. Das optimierte Modell ist durch sehr hohen Anteil an Glutaminsäure und durch hohe Anteile an Asparaginsäure, Arginin und Prolin gekennzeichnet. Bereits mit der Hälfte der getesteten 18 Aminosäuren resultierte ein im Aroma optimiertes Produkt, das sich im fleischähnlichen Qualitätseindruck nicht verbessern ließ.

Aroma concentrates with meaty flavour can be obtained by heat treatment of mixtures of glucose, amino acids, and other components in aqueous solution at optimized conditions. The MAILLARD reaction can be carried out under similar conditions by varying the ingredients to form flavour notes corresponding to those of meat of different origin.The aim of this paper is to report about the formation of the flavour notes ,,beef-like" and ,,chicken-like". The concentrates optimized by sensory evaluation are characterized analytically in both cases. In the centre there are comparising considerations between variants with pure amino acids and those with protein hydrolysate.Differences as well as conformities are discussed interpreting analytical results, firstly GC-profiles."Beef-like" and "poultry-like'' flavour concentrates can be synthesized. The necessary ingredients are for the first one amino acids or protein hydrolysates and glucose, for the second one oxidized fat is to be added.The quality of the aroma concentrates can sufficiently be characterized by sensory evaluation, extinction and GC-peaks. It is indispensable to choose a certain oxidation degree of the fat (rancidity) which can be determined by peroxide value and the correlating GCpeaks.Aroma concentrates which have meaty flavour can be produced by the thermal reaction of L-amino acid mixtures and protein hydrolysates with glucose under optimized conditions. Varying the reactants or the aroma precursors respectively very different flavour impressions are found, though the reaction conditions of the MAILLARD reaction are comparable. Thus the reaction can be carried out under similar conditions by varying the ingredients to form flavour notes corresponding to those of meat of different origin. This paper deals with the aroma impressions "roast beef-like" and "poultry-like". "Roast beef-like" aroma L-amino acids show different reaction behaviour with glucose. This results in several sensory descriptions [I, 21 and can furthermore be characterized by GC or simply by the degree of browning as given in Fig. 1. 9 of the 18 amino acids mentioned are necessary to form a meaty flavour (31: Asp, Arg, Ala, Cys, Gly, Glu, His, Ser, Pro. Besides glutamic acid and cysteine the most important ones are aspartic acid, proline and arginine. Cysteine -with the lowest degree of browning (as can be seen in Fig. 1) and generally known as an inhibitor of the MAILLARD reaction 42 Nahrung, Bd. 26, Heft 7,s