Aroma compound analysis of Eruca sativa (Brassicaceae) SPME headspace leaf samples using GC,GC-MS,and olfactometry     

Jirovetz L  Smith D  Buchbauer G 《Journal of agricultural and food chemistry》2002,50(16):4643-4646

The aroma compounds of rocket salad (Eruca sativa) SPME headspace samples of fresh leaves were analyzed using GC, GC-MS, and olfactometry. More than 50 constituents of the Eruca headspace could be identified to be essential volatiles, responsible for the characteristic intense green; herbal; nutty and almond-like; Brassicaceae-like (direction of cabbage, broccoli, and mustard); and horseradish-like aroma of these salad leaves. As aroma impact compounds, especially isothiocyanates, and derivatives of butane, hexane, octane, and nonane were identified. 4-Methylthiobutyl isothiocyanate (14.2%), cis-3-hexen-1-ol (11.0%), cis-3-hexenyl butanoate (10.8%), 5-methylthiopentyl isothiocyanate (9.3%), cis-3-hexenyl 2-methylbutanoate (5.4%), and 5-methylthiopentanenitrile (5.0%) were found in concentrations higher than 5.0% (calculated as % peak area of GC analysis using a nonpolar column).  相似文献   

Aroma quality differentiation of pyrazine derivatives using self-organizing molecular field analysis and artificial neural network   总被引：2，自引：0，他引：2  

Klocker J  Wailzer B  Buchbauer G  Wolschann P 《Journal of agricultural and food chemistry》2002,50(14):4069-4075

The encoding of various aroma impressions and the distinction between different aroma qualities are unsolved problems, as differences between aroma impressions can be described only in a qualitative but not in a quantitative manner. As a consequence, classifications of various aroma qualities cannot easily be performed by standard QSAR methods. To find a proper way to encode aroma impressions for SAR studies, a total of 50 pyrazine-based aroma compounds showing the aroma quality of earthy, green-earthy, or green are analyzed. Special attention is thereby turned on the mixed aroma impression green-earthy. Classifications on the whole data set as well as on smaller subsets are calculated using self-organizing molecular field analysis (SOMFA) and artificial neural networks (ANNs). SOMFA classifies between two or three aroma impressions, leading to models satisfying in predictive power. ANN analysis using multilayer perceptron network architecture with one hidden layer and nominal output as well as genetic regression neural network) with two hidden layers and numerical output both lead to a rather good performance rate of 94%.  相似文献   

Natürlicher gehalt und anthropogene anreicherung von Schwermetallen in den Sedimenten von Elbe, Eider, Trave und Schwentine     

Rudolf Lichtfuß  Gerhard Brümmer 《CATENA》1981,8(3-4)

The sediments of four rivers in Northern Germany were analysed for heavy metals. 371 sediment samples were taken from 24 investigation sites of the rivers Elbe, Eider, Trave and Schwentine and from North Sea tidal flat areas. Within each investigation site strong positive relationships exist between the heavy metal contents and the contents of the fine size fractions < 2 μm and < 20 μm of the sediments. To compare the metal contents in the sediments from different areas, differences in grain size were eliminated by computing the metal contents for a clay content of 25% by means of regression equations.The fluvial sediments at a few inland investigation sites, as well as the tidal flat sediments are not detectably polluted with heavy metals. Their metal contents could be used as background values for computing enrichment factors of polluted fluvial deposits.Sediments from the river Elbe in and upstream of the port of Hamburg, and from some parts of the rivers Eider and Trave near industrial and densely populated districts, are highly enriched with heavy metals. The highest enrichment factors are for Hg 85, Cd 56, Pb 37, Cu 34, Zn 29, As 19, Cr 6, Ni 4 and Co 3 times the background values.The ecological importance of the heavy metal contents in the sediments is discussed.  相似文献   

Spatial distribution of earthworms [Lumbricidae] in recultivated soils of the Rhenish lignite‐mining area,Germany     

Heinz‐Christian Fründ  Ellen Egbert  Gerhard Dumbeck 《植物养料与土壤学杂志》2004,167(4):494-502

The spatial distribution of earthworms was studied by means of combined formalin expulsion and hand sorting in three arable fields of the Rhenish lignite‐mining area that differed in their recultivation age (6, 12, 24 yr). In addition, pH and the spatial distribution of penetration resistances were measured to see if they are corresponding with the distribution of earthworms. Already the 6 yr old field had a rich population of endogeic, anecic, and epigeic earthworms (119 ind. m^–2, 48 g m^–2, 6 species). This quantity was similar to the 24 yr old site. The 12 yr old field was only sparsely populated by earthworms (5 ind. m^–2, 5 g m^–2, 3 species). In the 6 yr old field, the spatial distribution pattern showed a center of maximal earthworm abundances, corresponding to the distributional pattern of penetration resistances. In the old field (24 yr), the species varied in their spatial distribution, and there was no correspondence with the distribution of penetration resistance. In general, the penetration resistance at the youngest site was clearly lower than at the two older sites. The earthworm population in the 6 yr old field can be explained by cocoons contained in the dumped material. A calculation using literature data on earthworm‐population dynamics shows that a founding population of 400–600 reproductive individuals per hectare and a continuity of favorable growth conditions during the time of soil management is necessary for the development of the situation found at the 6 yr old site in this study.  相似文献   

Dosis- Wirkungs-Beziehungen zur Erfassung von Chemikalienwirkungen auf die mikrobielle Aktivität von Böden: I. Kurvenverläufe und Auswertungsmöglichkeiten     

Gerhard Welp  Gerhard W. Brümmer  Gerhard Rave 《植物养料与土壤学杂志》1991,154(3):159-168

Dose response curves: their use in soil microbiological research and possibilities of evaluation The relation between different concentrations of a toxicant in soils and the resulting effects on biological parameters can be described with dose response curves. Dose response curves make it possible to determine the concentrations of a chemical that create definite effects (?Effective Doses”?, e.g. ED₁₀ and ED₅₀ for 10- and 50% inhibitory effects) or to evaluate the rate of increase of inhibition with increasing concentrations. Some of the mostly used ways to extract these parameters from dose response curves are presented and examined with regard to their suitability in soil microbiological research. Besides graphical procedures for the evaluation of dose response curves a mathematical model for fitting quantitative dose response curves is introduced. With this model the confidence intervals of effective doses can be computed. By showing eight frequently appearing shapes of dose response curves the advantages and limitations of different ways to calculate effective doses are discussed.  相似文献   

Resistenzeigenschaften im Gersten- und Weizensortiment Gatersleben 29. Prüfung von Gersten auf ihr Verhalten gegenüber dem Milden Gerstenmosaik-Virus (barley mild mosaic virus,BaMMV), Gerstengelbmosaik-Virus (barley yellow mosaic virus,BaYMV),Drechslera teres (Sacc.)Shoem. undPuccinia hordei Otth     

Gerhard Proeseler  Horst Hartleb  Doris Kopahnke  Christian O. Lehmann 《Genetic Resources and Crop Evolution》1989,37(2):145-154

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Analysis of volatile compounds and triglycerides of seed oils extracted from different poppy varieties (Papaver somniferum L.)     

Krist S  Stuebiger G  Unterweger H  Bandion F  Buchbauer G 《Journal of agricultural and food chemistry》2005,53(21):8310-8316

Poppy seed oil (Oleum Papaveris Seminis) is used for culinary and pharmaceutical purposes, as well as for making soaps, paints, and varnishes. Astonishingly, hardly anything was yet known about the volatile compounds of this promising comestible. Likewise, there are no current published data about the triglyceride (TAG) composition of poppy seed oils available. In this investigation solid-phase microextraction (SPME) with DVB/Carboxen/PDMS Stable-Flex fiber was applied to the study of volatile compounds of several seed oil samples from Papaver somniferum L. (Papaveraceae). 1-Pentanol (3.3-4.9%), 1-hexanal (10.9-30.9%), 1-hexanol (5.3-33.7%), 2-pentylfuran (7.2-10.0%), and caproic acid (2.9-11.5%) could be identified as the main volatile compounds in all examined poppy seed oil samples. Furthermore, the TAG composition of these oils was analyzed by MALDI-ReTOF- and ESI-IT-MS/MS. The predominant TAG components were found to be composed of linoleic, oleic, and palmitic acid, comprising approximately 70% of the oils. TAG patterns of the different poppy varieties were found to be very homogeneous, showing also no significant differences in terms of the applied pressing method of the plant seeds.  相似文献   

Irrigation with plant extracts in ecofarming increases biomass production and mineral and organic nitrogen content of plants     

Gerhard Gramss  Klaus‐Dieter Voigt  Hans Bergmann 《植物养料与土壤学杂志》2003,166(5):612-620

Seedlings of alfalfa, rape, spinach, and wheat, potted on sandy soil, were irrigated with an aqueous extract of pea shoot (PE, 9.84 g dry weight l^–1) or a solution of Ca, K, Mg, P, and NO₃‐N salts (SS) in a concentration similar to that in PE, for 31–48 days. In comparison to water‐irrigated controls, both SS and PE treated plants showed nearly equal increases in shoot dry weight (29–40 %), whereas PE‐treated plants had higher fresh weights (38–84 %) due to increased succulence. Treatment with SS did not enhance, but sometimes even reduce, the concentrations of Ca, K, Mg, and several trace elements in shoot tissues. In contrast, PE‐treated plants had higher Ca, K, Mg, and organic N, but lower As and Ni contents and were thus of higher nutritive value. Reduced contents of metals in plant tissue correlated with their reduced solubility in the soil solution, which was not due to changes in pH. Fertilizer components such as K and Mg (metals of lower exchange intensity) were incorporated into the soil to release Ca, Sr, and Ba (metals of higher exchange intensity) and reduce the solubility of most trace elements and metal‐complexing humic substances. In addition, application of Ca precipitated heavy metals and humic complexes directly from the soil solution. This effect was partially overcome by PE. Its carboxylic acids could act as phytochelators of metal ions and as mobilizers of the highly diffusible humic substances which carry metals to roots. It is concluded that continuous PE application replaces the quantities of Ca, K, Mg, P, and organic N, but not of NO₃‐N consumed during plant growth. Using PE does not add any relevant quantities of toxic metals to the plant‐soil system.  相似文献   

Effect of Long-term Application of Farmyard Manure on Growth and Quality of Sugar Beet     

F. X. Maidl  G. Fischbeck 《Journal of Agronomy and Crop Science》1989,162(4):248-255

Field trials were conducted for two years on two farms which differed in long-term application of pig slurry in order to study the effects of long-term organic manuring, timing of slurry application (no slurry, slurry autumn, slurry spring) and additional doses of mineral N-fertilizer (0, 80, 160, 240 kg N/ha) on growth and quality of sugar beet. The results can be summarized as follows: 1. The effect of slurry application on growth of sugar beets varied markedly with the long-term differences in farm management. On the “arable farm” yield of beet roots increased substantially after slurry application and could not be replaced by higher doses of mineral N fertilizer. It is concluded therefore that “special effects” of farmyard manure are involved. On the “livestock farm”, however, highest beet yields were obtained on plots without slurry. Additionally slurry application caused a significant decrease in beet yields. 2. Sugar beets without slurry treatment always developed higher sugar contents and lower concentrations of alpha-amino-N, sodium and potassium as compared to beets from plots with slurry application. 3. Despite the decline in sugar content, sugar yield greatly increased by slurry application on the “arable farm”. The average increase in sugar yield was 10 dt/ha (=8%) with slurry application in autumn and amounted to 16 dt/ha (=14%) with spring application. On the livestock farm however, additional applications of slurry caused a decline in sugar yields in both years because of lower sugar contents and decrease in beet yields. 4. The utilization rate of slurry-N, depending mainly on time of application, annual rainfall and soil N mineralization, varied from 6–41%. On the “livestock farm” the utilization of slurry-N was only half of the rate obtained on the “arable farm”. 5. The application of small doses of slurry may cause a significant yield increase on farms without or only less livestock, while on farms with intensive livestock production continous slurry application needs to be considered as an expensive form of waste disposal. Therefore farms with high livestock density are advised to sell slurry to neighbouring farms without or only low animal production at a fair price for their mutual advantage.  相似文献   

Measurement of temperature generation in the corium of bovine claws during claw trimming with an angle grinder using different grinding and cutting disks     

Jantscher H  Kofler J  Altenbrunner-Martinek B  Schobesberger H  Haller J  Windischbauer G 《Berliner und Münchener tier?rztliche Wochenschrift》2005,118(7-8):280-289

On 80 bovine hindclaws from slaughtered cows a correct functional claw trimming (sole horn thickness 5 mm; group 1) and on further 80 hindclaws a standardised, incorrect claw trimming (sole horn thickness 2 mm; group 2) was performed using 4 different disks (one cutting, three grinding disks). Two thermocouples were inserted into the solar corium and the heat production on the corium was measured during claw trimming. During correct functional claw trimming with each of the 4 disks a temperature increase in the corium with a median of < or = 0.3 degrees C was calculated. During incorrect claw trimming (2 mm sole horn thickness) a temperature increase with a median of < or = 0.3 degrees C for the first three disks was determined. During claw trimming using the abrasive semiflexible plastic disk a median of 1.3 degrees C temperature increase was calculated. Comparison of the temperatures measured in the claws from group 1 and 2 showed a statistically significant difference between all four disks. Comparison of the temperature increase within each group (group 1 and 2) revealed a statistically significant difference between the cutting disk with steel blades and the abrasive, semiflexible plastic disk in both groups. The highest temperatures measured were 41.5 degrees C in group 1 using the disk with 70% amount of fitted hard metal granulate, and 42.2 degrees C in group 2 (temperature increase of 10.6 degrees C) using the abrasive semiflexible plastic disk. Under the experimental conditions of this study, only a very slight thermogenesis was found when a functional and correct claw trimming using the 4 tested disks was performed. This slight thermogenesis should not be able to cause thermic injury of the corium. By trimming the sole horn incorrectly (2 mm) the measured heat generation in the corium was minor, without danger of thermic insult, excepted for using the disk with a 70% amount of fitted hard metal granulate and the abrasive semiflexible plastic disk. Even, it is unlikely that a short term temperature increase of 10.6 degrees C can cause thermic insults of the solar corium.  相似文献