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21.
Pumpkin (Cucurbita pepo L.) seed oil is a common salad oil which is produced in Slovenia, Hungary and the southern parts of Austria. It is dark green and has a high content of free fatty acids. The seed itself can be eaten. Due to its colour and the foam formation, the oil cannot be used for cooking. The content of vitamin E, especially-tocopherol, is very high. The oil content of the pumpkin seed is about 50%. The variability in the oil content is very high resulting from a broad genetic diversity. Thus a breeding programme for increasing the oil productivity is very promising. The four dominant fatty acids are palmitic, stearic, oleic and linoleic acids. These four fatty acids make up 98±0.13% of the total amount of fatty acids, others being found at levels well below 0.5%.  相似文献   
22.
Heterocyclic aromatic amines in fried poultry meat   总被引:1,自引:0,他引:1  
 Heterocyclic aromatic amines are mutagenic compounds that are formed during heating of meat and fish. These substances are products of the reaction of creatine with amino acids and carbohydrates. It is recommended that exposure to these probable human carcinogens should be minimised. In fried boneless lean turkey breast meat five heterocyclic aromatic amines {2-amino-1-methyl-imidazo[4,5-f]quinoline (IQ), 2-amino-3,8-dimethyl-imidazo-[4,5-f]quinoline (MeIQ), 2-amino-3,8-dimethyl-imidazo[4,5-f]quinoxaline (MeIQx), 2-amino-3,4,8-trimethyl-imidazo[4,5-f]quinoxaline (4,8-DiMeIQx) and 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP)} were found. The temperature regime which was applied for frying resulted in a surface temperature of about 140°C. Clean-up was done by acid-base partition followed by solid-phase extraction (SPE) using blue cotton. HPLC analysis was carried out using electrochemical detection for IQ- and IQx-type compounds and fluorescence detection for PhIP. The low temperatures used during frying yielded comparably lower amounts of heterocyclic aromatic amines. The concentrations of the aromatic amines were as follows: IQ 1.1 μg/kg, MeIQ 0.9 μg/kg, MeIQx μg/kg, 4,8-DiMeIQx 0.4 μg/kg, and PhIP 3.8 μg/kg. Received: 19 February 1997 / Revised version: 21 April 1997  相似文献   
23.
 5,6-Dihydro-2,4,6-trimethyl-4H-1,3,5-dithiazine (thialdine) is an aroma-active compound that has been isolated from different species of meat. In this study we have investigated the formation of thialdine using the simultaneous distillation–extraction according to LikensNickerson for the extraction of aroma compounds. Three isomers of thialdine were identified in the aroma extract of cooked and dried hen meat. It was shown that these compounds are not genuine substances from the sample examined, but that they are artefacts formed during sample preparation. Received: 30 October 1996  相似文献   
24.
Pumpkin (Cucurbita pepo L.) seed oil is a common salad oil which is produced in the southern parts of Austria, Slovenia and Hungary. It is dark green and has a high content of free fatty acids. Due to its colour, the oil cannot be used for cooking. The content of vitamin E, especially-tocopherol, is very high. The oil content of the pumpkin seed is about 50%. The seed itself can be eaten. Therefore a pumpkin variety with high vitamin E content is desirable. The aim of this work was to find a variety ofCucurbita pepo which has a high oil yield and a high vitamin E content. A total of 100 breeding lines were tested for their tocopherol content. The tocopherols and tocotrienols are extracted with hexane and analysed by NP-HPLC/FLD with hexane/dioxan (96/4) as eluent, with fluorescence detection at 292/335 nm. The/gg-tocopherol content, which is about 5–10 times as much as that of -tocopherol varies over a broad range (41–620 mg/kg dry pumpkin seeds).- and-tocopherol are found at low levels.  相似文献   
25.
The chromium content in foods is relatively low and the most foods have a content below 0,1 ppm. Only spices, cacao, cacao products, poppy and whole meal products contain higher contents. The often published high chromium content of corn germ oil could not be verified. We did not find any chromium enrichment in the entrails of a cow. In addition the chromium contents of each food are strong deviated. The analysed values were sometimes lower than in literature. We expect that the elder values are higher because of different contaminations in some cases.  相似文献   
26.
Zusammenfassung Die Aufnahme von Arsen, Blei und Cadmium durch Kleinkindernahrung während der ersten zwölf Lebensmonate wurde untersucht.Die ermittelten Aufnahmewerte lagen für Arsen bei 0,03–0,15, für Blei bei 0,18–2,5 und für Cadmium bei 0,04–0,61 mg/Person und Monat.Berechnet man die Aufnahmewerte auf das kg Körpergewicht, so zeigte sich, daß die Werte für Arsen und Cadmium im Bereich der Belastung bei Erwachsenen lagen. Die Bleibelastung bei Kleinkindern lag jedoch deutlich über der bei Erwachsenen ermittelten.
Trace elements in baby nutrition: arsenic, lead, cadmium
Summary The uptake by babies from nutritional sources of lead, cadmium and arsenic was evaluated during the first twelve months of life.Arsenic, lead and cadmium consumptions were in the range of 0.03–0.15, 0.18–2.50, 0.04–0.61 mg/person and month respectively.The total uptake expressed in g/kg body weight was compared with figures from a study undertaken with adults. In this comparison arsenic and cadmium uptake was within the same range. An exeption was lead uptake, which was much higher in babies, than in adults.


Als Teil eines Vortrages präsentiert bei der Internationalen Konferenz Management and Control of Heavy Metals in the Environment vom 18.–21. 9. 1979, Imperial College, London  相似文献   
27.
The influence of the packaging material on chemical and sensory changes of fruit juices and nectars has been topic of several previous studies. Nevertheless, especially comparing the two materials glass and laminated carton package, the results have been very contradictory. Consequently, we re-investigated the influence of these still widely used packaging materials on the changes of a multivitamin nectar in course of a storage period of 7 weeks at elevated temperature (37°C). Chemical changes were observed by following concentration changes of several volatile compounds using headspace-solid-phase microextraction with subsequent gas chromatography-mass spectrometry. Difference testing was used to determine whether the sensory properties of the product changed more quickly in any of the packaging materials. Results showed a distinct influence of the packaging material on the changes of the product. Effects generally known as ‘flavour sorption’ were observed and caused different concentration changes of several volatile compounds in dependence of the packaging material. In contrast to other previously published results, sensory evaluation by means of difference tests showed that the product filled in the laminated carton package changed much faster than the product in the glass bottle.  相似文献   
28.
Total anthocyanin content and qualitative and quantitative anthocyanin composition in black chokeberries [Aronia melanocarpa (Michx.) Elliott] were determined by TLC, HPLC and UV/VIS methods. After ethanol extraction and cleaning operations we found, in different varieties of black chokeberries (Nero, Rubina and Viking), between 650 mg and 850 mg total anthocyanins per 100 g dry weight. The anthocyanin composition was analysed; (cyanidin was the only aglycon (anthocyanidin) found and the monosaccharides galactose (68.9%), arabinose (27.5%), xylose (2.3%) and glucose (1.3%) were identified. The quantitative distribution is given in parentheses. In comparison with other berries and fruits, which are rich in anthocyanins, black chokeberries have a simple anthocyanin spectrum, but a many times higher anthocyanin content. For that reason chokeberries are of special interest as a source for a natural colourant.  相似文献   
29.
Sensorische und instrumentelle analytische Untersuchungen des Kiwi-Aromas   总被引:1,自引:0,他引:1  
Zusammenfassung Unter Verwendung der Gaschromatographie, der Massenspektrometrie und sensorischer Methoden wie der Schnüffelanalyse wurde die Zusammensetzung des Aromas von frischen und länger gelagerten bzw. überreifen Kiwis untersucht. Eine Reihe bisher nicht beschriebener flüchtiger Substanzen konnte identifiziert werden. Unterschiede in der Zusammensetzung der flüchtigen Komponenten zwischen frisch bereiteten und reifen Früchten einerseits und überreifen Kiwis und tiefgefrorenem Kiwipüree andererseits wurden festgestellt. Eine Verringerung des Gehaltes an C-6-Verbindungen und Buttersäureester geht Hand in Hand mit einem Anstieg des Gehaltes an Terpenester und Linalool. Diese Veränderung korreliert mit der Veränderung des Kiwi-Aromas von einer frisch-grünen zu einer betont estrigen Note.
Sensorial and instrumental analytical investigations of Kiwi flavour
Gas chromatography, mass spectrometry and sniffing analysis were performed in order to obtain information on the composition of aroma extracts prepared from fresh Kiwi fruit and that stored for long time. Several volatile substances which have not yet been reported could be identified. Differences in the chemical composition between the volatiles of freshly prepared mature and over-ripe fruit and deep-frozen Kiwis have been detected. A reduction of C-6 compounds and butyric acid esters guided by an increase in the formation of terpenic esters and linalool has been observed. These findings correlate with a shift in the flavour impression from a fresh-green note to a more ester like one. This fact can be employed to judge the quality of Kiwi products processed in the food industry.


Auszugsweise vorgetragen bei EURO FOOD CHEM IV Loen/Norwegen 1.-4.4. 1987 und den Österreichischen Chemietagen 3.-6.11. 1987 Wien  相似文献   
30.
 The ability of supercritical fluid extraction (SFE) to extract nitropolycyclic aromatic hydrocarbons (nitro-PAHs) from tea matrices is described and discussed. An experimental approach was set up to determine the influences of various extraction parameters, i. e. pressure, temperature, extraction time and addition of modifier. The evaluation of the method was carried out by analysing samples of fortified tea and then comparing the results with those obtained from conventional extraction procedures, such as Soxhlet extraction and ultrasonication. SFE proved to be far better than the conventional methods at monitoring levels of nitro-PAHs in tea. However, due to the wide range of polarity of the analytes investigated, selective extraction with supercritical carbon dioxide was not possible; hence, subsequent purification steps were necessary, prior to the final GC/MSD analyses. The nitro-PAHs and PAHs concentrations in several tea samples were determined, any correlation between nitro-PAHs and PAHs was studied and the results are presented in this article. Received: 13 January 1997 / Revised version: 21 February 1997  相似文献   
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