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1.
Andreas Rossmann Wilhelm Rieth und Hanns -Ludwig Schmidt 《Zeitschrift für Lebensmitteluntersuchung und -Forschung A》1990,191(4-5):259-264
Zusammenfassung Die D- und die 13C-Werte der Zuk-ker und die 13C-Werte fester Bestandteile (Pulpe; bei Citrussäften) aus einer größeren Anzahl von naturbelassenen Apfel-, Grapefruit-, Orangen- und Zitronen-Säften sowie die D- und 13C-Werte von Glucose aus Maisund Kartoffelstärkehydrolysaten sowie von Rübenzuk-ker wurden bestimmt. Die Resultate zeigen pflanzen- und klimatypische Bereiche, die trotz einiger Überschneidungen Verfälschungen (Zuckerung) in unbekannten Proben zu erkennen erlauben. Ein Vergleich der Ergebnisse mit Resultaten konventioneller Analysen (Bestimmung der RSK-Parameter) führt zu sehr guten Übereinstimmungen, so daß aus der Kombination dieser konventionellen Untersuchungsmethoden mit der Isotopen-Verhältnismessung ein zuverlässiger Nachweis des unerlaubten Zuckerzusatzes von Zucker aus C3- oder C4-Pflanzen zu Säften resultiert. Als weiterer Ausbau des Verfahrens wird der Einbezug von 18O-Bestimmungen empfohlen.
Possibilities and results of the combination of hydrogen and carbon stable isotope ratio determination with results of conventional analyses (RSK-values) for the proof of sugar addition to fruit juices
Summary The D and 13C values of the sugars and the 13C values of the solid ingredients (pulp; in citrus juices) of a larger number of natural apple, grapefruit, orange and lemon juices, as well as the D and 13C values of glucose from corn and potato starch hydrolysates and from beet sugar, have been determined. The values cover plant and climate typical areas which permit, in spite of some overlap, the recognition of the addition of sugar to the juices. A comparison of the results with those of conventional analyses (determination of RSK parameters) agree satisfactorily, thus demonstrating that a combination of these classical criteria together with the isotope ratio determination prove that sugars form C3-or C4-plants are illegally added to the juices. With respect to further development of the method future integration of 18O measurements is recommended.相似文献
2.
The combination of gas chromatography-combustion-isotope ratio mass spectrometry (GC-C-IRMS) and gas chromatography-pyrolysis-isotope ratio mass spectrometry (GC-P-IRMS) is applied to the authenticity assessment of cinnamaldehyde from various sources. For that reason, cinnamon oils were self-prepared by steam distillation from three different varieties of cinnamon bark on the market, C. ceylanicum (ceylon), C. cassia (cassia) and C. burmanii (cassia vera). Furthermore, the so-called wood cinnamon was investigated, which is produced from the outer bark of older branches of cinnamon of minor quality. Self-prepared oils were analysed from commercial cinnamon powder. In addition several commercial samples of cinnamon oil and cinnamaldehyde, some of them declared to be natural, were investigated.
2V-SMOW and
13CV-PDB values of cinnamaldehyde were determined and characteristic authenticity ranges were deduced, allowing the differentiation between synthetic and natural samples. By correlation of both the
2V-SMOW and
13CV-PDB values, characteristic authenticity ranges were defined for ceylon, cassia and wood cinnamon. The
2V-SMOW and
13CV-PDB values of cassia vera samples are in the range of cassia. By comparing the
2V-SMOW values of different self-prepared samples (ground bark, distillate) of cinnamon determined by TC/EA-IRMS with the corresponding GC-IRMS values, online GC-IRMS methods are proved to be essential in the authentication of complex natural products. 相似文献
3.
Andreas Roßmann und Peter Trimborn 《Zeitschrift für Lebensmitteluntersuchung und -Forschung A》1996,203(3):277-282
Using a modified method for the determination of the18O/16O ratio in water the 18O values for authentic apple juice concentrates (70 °Brix) of known origin, for industrially produced invert sugar syrups, for commercial apple juice concentrates, and for spiked apple juice concentrates have been measured. The 18O values for the authentic apple juice concentrates were correlated to the 18O values of the related pressed (single strenght) apple juices and to the sugar content of the concentrates in °Brix. The results for the samples were compared to and evaluated together with the 13C values for the sugars. Concluding from the results, a minimum value for authentic apple juice concentrate of 0 to 1%., depending on the regional origin of the material, is suggested, while the determination of the 18O value of apple juice concentrate is preferably used in addition to the already well known methods on the basis of stable isotope measurement. 相似文献
4.
Improving fruit juice origin assignment by combined carbon and nitrogen isotope ratio determination in pulps 总被引:1,自引:0,他引:1
Barbara E. Kornexl Andreas Roßmann Hanns -Ludwig Schmidt 《Zeitschrift für Lebensmitteluntersuchung und -Forschung A》1996,202(1):55-59
The combination of the relative abundances of carbon and nitrogen isotopes (13C- and 15N-values) in fruit juice pulps led to characteristic clusters, on the basis of which regional origin assignments of citrus juices were possible, which would not have been attained on the basis of only one of these parameters. Thus, while the 13C-values of juice pulps from Italy partially overlapped with those from Brazil, the 15N-values permitted an origin assignment. First attempts to extend this multi-isotope analysis to a multi-compound15N analysis, by correlating the 15N-values of fruit juice pulps to those of free amino acids, were promising. The results obtained were in line with general observation on15N abundances and biochemical correlations of secondary plant products. 相似文献
5.
Ursula Palm Christiane Askari Uwe Hener Eckhard Jakob Claudia Mandler Martin Geßner Armin Mosandl Wilfried A. König Petra Evers und Ralph Krebber 《Zeitschrift für Lebensmitteluntersuchung und -Forschung A》1991,192(3):209-213
Zusammenfassung 5-Alkyl-substituierte-Lactone finden sich als aromarelevante Substanzen in tierischen Fetten, aber auch in einigen Früchten. Vor kurzem gelang die erste direkte gaschromatographische Stereodifferenzierung einiger-Lactone an der chiralen Phase Oktakis(3-O-butyryl-2,6-di-O-pentyl)--cyclodextrin [4]. Es wird nun die Enantiomerentrennung der-Lactone bis zu den langkettigen Verbindungen-Trideca-(-C13-)- und-Tetradeca-(-C14-)-lacton aufgezeigt. Über optisch reine Referenzsubstanzen konnte die Elutionsfolge S(I), R(II) der drei wichtigsten aromarelevanten Vertreter dieser-Lactonklasse bestimmt werden. Die Enantiomerenverteilung der C8-, C10-, C12--Lactone im Wasserdampfdestillat verschiedener Milchprodukte (Milch, Sahne, Butter), in Margarine sowie im Kokosnußfleisch wurde exemplarisch mit Hilfe der HRGC, auch unter Einsatz der multidimensionalen Gaschromatographie (MDGC), untersucht. Es zeigten sich charakteristische, substratspezifische Enantiomerenverteilungen. Die Verteilungsmuster der untersuchten Spiegelbildisomeren aus Kokosnüssen unterschieden sich wesentlich von denen der Milchprodukte.
Stereoisomeric flavour compoundsXLVII. Direct chirospecific HRGC-analysis of natural -lactones
Summary 5-Alkylated-lactones are well known flavour compounds in animal fats and also some special kinds of fruit. Recently, the first direct stereo-differentiation of chiral-lactones was reported using Oktakis(3-O-butyryl-2,6-di-O-pentyl)--cyclodextrin as the chiral stationary phase [4]. The enantiomeric separation of-lactones up to the long-chain compounds-trideca-(-C13–) and-tetradeca-(-C14–)-lactone is demonstrated. By means of optically pure references, the order of elution S(I), R(II) was determined for the important flavour compounds-octa-,-deca-, and-dodecalactone. Analysis of the steam distillate of some dairy products (milk, cream, butter), of margarine and of coconut has been carried out, in order to yield the enantiomeric distribution of C8-, C10- and C12--lactones by HRGC and multidimensional gas chromatography. Characteristic and product-specific ratios of-lactone enantiomers are detected. The pattern of enantiomeric composition of-octa-,-deca-,-dodecalactone in coconuts differs completely from that found in the dairy products.相似文献
6.
Jerzy Falandysz 《Zeitschrift für Lebensmitteluntersuchung und -Forschung A》1986,182(2):136-139
Summary Hexachlorobenzene (HCB), -, -, - and -benzenehexachloride (BHC; HCH),p,p-DDE,o,p-DDD,o,p-DDT,p,p-DDD and p,p-DDT (DDT) and polychlorinated biphenyls (PCB) levels have been determined in muscle tissue of 207 cod (Gadus morhua) netted during 1983 in different regions in the southern part of the Baltic Sea. The mean levels found for cod muscle tissue (g/kg) related to wet weight were: 0.65 HCB, 1.2 -BHC, 9.0 -BHC, 2.8 -BHC, -BHC remained undetected, 13 BHC, 4.4p,p-DDE,o,p-DDD ando,p-DDT remained undetected, 4.0p,p-DDD, 1.8p,p-DDT, 10 DDT and 55 PCBs. The results are compared with levels found in cod caught in different regions of the Baltic Sea during 1967–1983, and reported previously by other authors.
Partially with financial support under grant PR-4 (Sea Fisheries Institute) 相似文献
Organochlorpesticide und polychlorierte Biphenyle in Kabeljau aus der südlichen Ostsee,1983
Zusammenfassung Die Werte für Hexachlorbenzol (HCB), -, , -, und -Benzolhexachlorid (BHC; HCH),p,p-DDE,o,p-DDD,o,p-DDT,p,p-DDD undp,pDDT (DDT) und polychlorierte Biphenyle (PCB) wurden im Muskelgewebe von 207 Kabeljaus (Gadus morhua), mit Netz in verschiedenen Regionen der südlichen Ostsee 1983 gefangen, bestimmt. Die mittleren Werte, bezogen auf das Frischgewicht, waren: 0,65 g/kg HCB, 1,2 g/kg -BHC, 9,0 g/kg -BHC, 2,8 g/kg -BCH, -BHC blieben unbestimmt, 13 g/kg BHC, 4,4 g/kgp,p-DDE,o,p-DDD undo,p-DDT blieben unbestimmt, 4,0p,p-DDD, 1,8p,p-DDT, 10 g/kg DDT und 55 g/kg PCB. Die Ergebnisse wurden mit den Werten früherer Jahre von 1967–1983 und mit denen anderer Autoren verglichen.
Partially with financial support under grant PR-4 (Sea Fisheries Institute) 相似文献
7.
Detmar Lehmann Birgit Maas Armin Mosandl 《Zeitschrift für Lebensmitteluntersuchung und -Forschung A》1995,201(1):55-61
The enantiomeric distributions of - and -lactones from dairy products are determined by enantioselective multidimensional gas chromatography. By using heptakis(2,3-di-O-acetyl-6-O-TBDMS)--cyclodextrin as the chiral main column, the simultaneous stereodifferentiation of the - and -lactones C13–C18 is reported for the first time. Genuine lactones of dairy products preferably occur as (R)-enantiomers. Flavoured margarine and coconut are analysed and discussed. Reference compounds are synthesized as racemates and separated by enantioselective HPLC into the enantiomers. Chiral compounds of characteristic enantiomeric ratios are detected irrespective of the manufacturing processes used. 相似文献
8.
Malgorzata Nogala-Kalucka Jozef Korczak Ibrahim Elmadfa Karl-Heinz Wagner 《European Food Research and Technology》2005,221(3-4):291-297
Information on the antioxidative potential of -tocopherol is scanty, in particular for frying conditions. This study was aimed at assessing the antioxidative effects and degradation of - and -tocopherol between 0.01 and 0.1% on the oxidation of a commercial frying fat at 160 °C. Oxidation experiments were performed by assessing every 15 or 30 min the peroxide value and conjugated dienes as primary oxidation products, p-anisidine reactive products and hexanal as secondary oxidation products, as well as the stability of tocopherols. The fatty acid composition was determined after 6 h. The fat samples enriched with -tocopherol were considerably less resistant to oxidation compared to those with -tocopherol. Both primary and secondary oxidation parameters increased their speed of formation with -tocopherol but not with -tocopherol. The latter observation is confirmed for the total amount of oxidation and also for the first stage, showing a lag phase only for -tocopherol. These antioxidative effects can be due to the higher stability of -tocopherol compared to -tocopherol, which is oxidized faster into tocopheryl radicals, which can participate in side reactions that result in an acceleration of the oxidation speed. Neither -tocopherol nor -tocopherol influenced the fatty acid pattern. The investigation showed that during mild frying conditions the tocopherol homologues displayed various antioxidant activities. The less effective homologue, -tocopherol, underwent disintegration more quickly than -tocopherol. 相似文献
9.
Jerzy Falandysz 《Zeitschrift für Lebensmitteluntersuchung und -Forschung A》1986,182(2):131-135
Summary Hexachlorobenzene (HCB), -, -, - and -benzenehexachloride (BHC, HCH),p,p-DDE,o,p-DDD,o,p-DDT,p,p-DDD andp,p-DDT (DDT) and polychlorinated biphenyls (PCB) levels have been determined in muscle tissue of 187 herring (Clupea harengus) netted during 1983 in a different regions in the southern part of the Baltic Sea. The mean levels found for herring muscle tissue related to wet weight (g/kg) were: 14 HCB, 18 -BHC, 23 -BHC, 14 -BHC, -BHC remained undetected, 56 BHC, 115p,p-DDE,o,p-DDD ando,p-DDT remained undetected, 84p,p-DDD, 51p,p-DDT, 250 DDT and 530 PCB. The levels of organochlorine pesticides determined in wet muscles or extractable lipids of her ring are nearly 2–3 times as high as those noted in fish sampled in the same area in two years before, whilst for PCBs the wet weight levels were comparable, and when based on a lipid weight are somewhat higher. The results are compared with levels found in herring collected in different regions of the Baltic Sea during 1965–1983, and reported previously by other authors.
Partially with financial support under grant PR-4 (Sea Fisheries Institute) 相似文献
Organochlorpesticide und polychlorierte Biphenyle in Hering aus der südlichen Ostsee, 1983
Zusammenfassung Hexachlorbenzol (HCB), -, -, -und -Benzolhexachlorid (BHC, HCH),p,p-DDE,o,p-DDD,o,p-DDT,p,p-DDD undp,p-DDT (DDT) und polychlorierte Biphenyle (PCB) wurde im Muskelgewebe von 187 Heringen (Clupea harengus) 1983 in verschiedenen Regionen der südlichen Ostsee mit Netz gefangen, bestimmt. Die mittleren gefundenen Mengen für das Muskelgewebe von Heringen, bezogen auf das Frischgewicht waren: 14 g/kg HCB, 18 g/kg -BHC, 23 g/kg -BHC, 14 g/kg -BHC, -BHC blieb unentdeckt, 56 g/kg -BHC, 115 g/kg p,p-DDE,o,p-DDD undo,p-DDT blieb unentdeckt, 84 gmg/kgp,p-DDD, 51 g/kgp,p-DDT, 250 g/kg -DDT und 530 gmg/kg PCB. Die Mengen für Organo-chlorpesticide in frischen Muscheln oder in den extrahierten Lipiden waren zwei- bis dreimal höher als die in den Jahren zuvor bestimmten, während die für PCB vergleichbar gewesen sind, und wenn sie auf die Fettmenge bezogen wurden, lagen sie etwas höher. Die Ergebnisse wurden verglichen mit den gefundenen in anderen Regionen der Ostsee während der Jahre 1965–1983 und mit denen anderer Autoren.
Partially with financial support under grant PR-4 (Sea Fisheries Institute) 相似文献
10.
Jerzy Falandysz 《Zeitschrift für Lebensmitteluntersuchung und -Forschung A》1986,182(3):224-227
Summary Hexachlorobenzene (HCB), -, -, - and -benzenehexachloride (BHC; HCH),p,p-DDE,o,p-DDD,o,p-DDT,p,p-DDD andp,p-DDT (DDT) and polychlorinated biphenyls (PCB) levels have been determined in livers of 210 cod (Gadus morhua) netted during 1983 in a different regions in the southern part of the Baltic Sea. The mean levels found for cod livers related to wet weight (mg/kg) were: 0.096 HCB, 0.15 -BHC, -BHC was found in trace amounts, 0.098 -BHC, -BHC remained undetected, 0.26 BHC, 1.1p,p-DDE,o,p-DDD ando,p-DDT remained undetected, 1.1p,p-DDD, 0.39p,p-DDT, 2.6 DDT and 7.2 PCB. The levels of DDT, BHC and HCB found are comparable with those noted in livers taken from cod of the same length class and netted in 1981, whilst-for PCB somewhat lower levels were found. Because of heavy contamination with PCBs, DDT, BHC and HCB the livers of cod caught in Baltic Sea still remain insuitable for human consumption.
Partially with financial support under grant PR-4 (Sea Fisheries Institute) 相似文献
Organochlorpesticide und polychlorierte Biphenyle in der Kabeljauleber aus der südlichen Ostsee, 1983
Zusammenfassung Hexachlorbenzol (HCB), -, -, -und -Benzolhexachlorid (BHC; HCH), p,p,p-DDE,o,p-DDD,o,p-DDT,p,p-DDD undp,p-DDT (DDT) und polychlorierte Biphenyle (PCB) wurde in der Leber von 210 Kabeljaus (Gadus morhua), im Netz 1983 in verschiedenen Regionen der südlichen Ostsee gefangen, bestimmt. Die mittleren gefundenen Werte für die Kabeljauleber, bezogen auf das Frischgewicht, betrugen: 0.096 mg/kg HCB, 0,15 mg/kg -BHC, -BHC wurden in Spurenmengen gefunden, 0.098 mg/kg -BHC, -BHC blieb unentdeckt, 0,26 mg/kg BHC, 1,1 mg/kgp,p-DDE,o,p-DDD undo,p-DDT blieb unentdeckt, 1,1 mg/kgp,p-DDD, 0,39 mg/kgp,p-DDT, 2,6 mg/kg DDT und 7,2 mg/kg PCB. Die gefundenen Mengen von DDT, BHC und HCB sind mit denen in der Kabeljauleber der Werte von 1981 vergleichbar, während die für PCB etwas niedriger gefunden wurde. Die schwere Kontamination mit PCB, DDT, BHC und HCB in der Leber, der in der Ostsee gefangenen Kabeljaus, läßt einen Verzehr für den Menschen nicht zu.
Partially with financial support under grant PR-4 (Sea Fisheries Institute) 相似文献