• UNDERSTAND
    Food Production
  • UNDERSTAND
    Food Adulteration
  • UNDERSTAND
    Food Provenance

Lebensmittelauthentizität

Mit immer komplexer werdenden Lieferketten von Lebensmitteln wird es auch zunehmend komplizierter, deren Herkunft zu verifizieren. Mit Hilfe der Stabilisotopenanalyse können preiswerte Fälschungen von Premiumprodukten und rechtlich geschützten Lebensmitteln nachgewiesen werden. Indem die einzigarte Isotopensignatur eines Lebensmittels analysiert wird, kann die wahre Herkunft der Inhaltsstoffe ermittelt werden.

Demselben Prinzip folgend kann die Aromaindustrie ihre Produkte durch den Einsatz eines Multi-Element-Isotopenfingerabdrucks besser vor Kopien schützen. Die Stabilisotopenanalyse kann auch dazu genutzt werden, um biologische Landwirtschaftspraktiken zu verifizieren, oder um die Zugabe von minderwertigen Zusatzstoffen zu Premiumprodukten aufzudecken. Dies trägt zum Verbraucherschutz bei und hilft aufrichtigen Herstellern, ihren guten Ruf zu wahren.

 

Obst, Gemüse, Fleisch

Mit Hilfe der Multi-Element-Isotopenanalyse kann eine Vielzahl von Informationen über die geografische Herkunft und mögliche Verfälschungen von Nahrungsmitteln gewonnen werden. Dank unserer einzigartigen Advanced Purge and Trap (APT) Technologie, die eine unschlagbare Gastrennung ermöglicht, können Sie mit unserem Spektrum von Hochleistungs-Elementaranalysatoren für die Stabilistopenanalyse (EA-IRMS) Ihre Proben schnell analysieren. Mit einer Garantie von 10 Jahren auf den Ofen können Sie sich auf unsere Geräte jederzeit verlassen.

Wein & Fruchtsaft

Abhängig von ihrer geografischen Herkunft oder Bezeichnung können Weine mit einem großen Aufpreis verkauft werden. Fruchtsäfte ohne Zusatz von Wasser sind Säften aus Konzentrat vorzuziehen. Um Abweichungen von den Deklarationen dieser Produkte festzustellen, wird die 18O- und 2H-Isotopenanalyse herangezogen, die eine Probe aufgrund der natürlichen meteorologischen Variation des Wassers direkt einem Ursprungsort zuordnen kann. Unser iso FLOW System bietet bei hohem Probendurchsatz eine außergewöhnliche Analyse dieser Proben.

Honig

Honig gehört zu den Top 5 der weltweit am häufigsten verfälschten Lebensmittel. Stabilisotopenanalyse kann dazu beitragen, diese Fälschungen zu erkennen: Unsere EA-IRMS-Systeme sind in der Lage, die Methode AOAC 998.12 für die schnelle Erkennung von Honigverfälschungen mit C4-Zucker anzuwenden. Unsere LC-IRMS-Systeme ermöglichen es sogar, noch komplexere Verfälschungen mit C3-Zuckern zu detektieren, indem sie eine spezifische Isotopenanalyse der intrinsischen Fructose, Glucose und höheren Zuckern durchführen.

Publikationen zum Thema Lebensmittelauthentizität mit unseren Geräten

Unsere Kunden nutzen unsere Geräte für erstaunliche Forschungsprojekte und analysieren Lebensmittel und Aromen auf ihre isotopische Zusammensetzung. Um Ihnen zu zeigen, wie unsere Kunden ihre Forschung durchführen und wie unsere IRMS-Geräte eingesetzt werden, haben wir eine Reihe von Fachpublikationen gesammelt, die unsere Produkte namentlich nennen. Die Informationen zu diesen Fachartikeln finden Sie unten. Durch Klicken auf den Link werden Sie zur Website des jeweiligen Zeitschriftenverlags weitergeleitet, wo Sie die Publikation herunterladen können.

Wenn Sie unsere Publikationsdatenbank durchsuchen möchten oder die Liste der Ergebnisse an sich selbst oder an Ihre Kollegen mailen möchten, dann werfen Sie einen Blick auf unsere gesamte Publikationsdatenbank.

63 Ergebnisse:

Effectiveness of carbon isotopic signature for estimating soil erosion and deposition rates in Sicilian vineyards
Soil and Tillage Research (2015)
Agata Novara, Cerdà Artemi, Dazzi Carmelo, Lo Papa Giuseppe, Santoro Antonino, Gristina Luciano

Traditional methods for measurement of soil erosion provide information on erosion rates and mechanisms but fail to determine the spatial distribution of sediment redistribution. Recent studies have used carbon (C) stable isotopes to trace sediment and to monitor soil organic carbon (SOC) redistribution. The difference in δ13C values in a slope-transect or in a watershed provides information about the source of suspended organic matter and sediment removal and deposition, but miss enough information to quantify sediment loss. The objective of this research was to develop a method to estimate soil erosion using the natural discrimination of δ13C-SOC with soil depth, comparing δ13C variation in different profiles sampled along a slope. The method was developed in a Sicilian vineyard, where soil losses were previously measured by means of Gerlach collectors and by pole methods. δ13C was measured in different soil profiles in the top, middle and bottom of the slope. The variation of δ13C with soil depth in the profiles along the slope was compared to the δ13C values of the near flat area, in order to reconstruct the original topography of slope transect. δ13C increased with depth and decreased from the top to the bottom of the slope in all pedons. The soil δ13C signature ranged from −26.7‰ to −25.7‰, from −26.2‰ to −25.3‰, and from −27.0‰ to −24.8‰ in the profiles at the top, middle, and bottom of the slope, respectively. The rates of δ13C enrichment along the slope could be explained as different rates of detachment and deposition. The erosion value estimated with δ13C method was 77Mgha−1y−1. The comparison of different methods (102Mgha−1y−1 with the pole method and 89.6Mgha−1y−1 with the Gerlach method) indicate that carbon isotopic signature is a reliable indicator of short- and long-term soil erosion processes.

Stable and radiogenic isotopes as indicators of agri-food provenance: Insights from artisanal cheeses from Quebec, Canada
International Dairy Journal (2015)
Ross Stevenson, Stéphanie Desrochers, Jean-François Hélie

Stable (H,O,N,C) and radiogenic isotope (Sr) data for cheese, milk, animal feed and soil from six artisanal cheese producers in Quebec, Canada, demonstrated the potential of isotope geochemistry in linking land/terroir to agricultural produce. The hydrogen and oxygen isotope compositions of the water, milk and cheese samples showed good general alignment with the Global Meteoric Water Line, with small off-sets in the milk and cheese samples related to cheese production. Carbon and nitrogen isotope data for the cheese and milk reflect the diet of the cattle and fertilization of the cattle grazing pastures. The strontium isotope compositions of the soils, milk and cheese are similar for a given farm/cheese producer, but vary widely between producers due to differences in geology. Combining the climate-sensitive δ18O and geology-sensitive 87Sr/86Sr proxies shows potential for discriminating between Quebec artisanal cheeses, commercial Canadian cheeses and European cheeses.
Schlagworte: carbon , hydrogen , nitrogen , oxygen , food

Contemporary Carbon Content of Bis (2-ethylhexyl) Phthalate in Butter
FOOD CHEMISTRY (2015)
T Tong, J M Ondov, B A Buchholz, M C Vanderveer

The fraction of naturally produced bis (2-ethylhexyl) phthalate (DEHP), a ubiquitous plasticizer known to contaminate packaged foods, was determined for each of five 1.10 kg samples of unsalted market butter by accelerator mass spectrometry (AMS). After extraction and concentration enrichment with liquid–liquid extraction, flash column chromatography, and preparative-scale high performance liquid chromatography, each sample provided ≈250 μg extracts of DEHP with carbon purity ranging from 92.5 ± 1.2% (n = 3, 1σ) to 97.1 ± 0.8% (n = 3, 1σ) as measured with gas chromatography mass spectrometry (GC–MS). After corrections for method blank DEHP, co-eluting compounds, and unidentified carbon, the mean fraction of naturally produced DEHP in butter was determined to be 0.16 ± 0.12 (n = 5, 1σ). To our knowledge, this is the first report of the contemporary fraction of DEHP isolated from market butter in the U.S.
Schlagworte: carbon , food , elem

Stable Carbon Isotope Ratio for Sugar, Amino Acid, and Caffeine by Liquid Chromatography/Isotope Ratio Mass Spectrometry
Procedia Earth and Planetary Science (2015)
Nana Suto, Hiroto Kawashim

In 2004, liquid chromatography coupled with isotope ratio mass spectrometry (LC/IRMS) has been developed. Today, LC/IRMS system has been used for various compounds. Stable isotope analysis has proved to be a powerful tool for source apportionment of various compounds. We analysed δ13C of 6 sugar, 10 amino acid and 2 caffeine samples using direct injection mode and online LC/IRMS mode. In this study, the ion chromatography system was coupled with IRMS instrument. On direct injection mode, the standard deviation for all samples were <0.26‰. The difference between EA/IRMS and direct injection mode was 0.41‰ (sugar), 2.01‰ (amino acid), 5.09‰ (caffeine, Wako Pure Chemical Industries), and 7.41‰ (caffeine, IAEA). The differences for amino acid and caffeine samples were bigger than sugar samples. The reason of the difference is still unclear. In the case of online LC/IRMS mode, the differences between the EA/IRMS and online LC/IRMS without phosphoric acid for amino acid were from 2.54‰ to 9.93‰. In contrast, when 1% phosphoric acid was added, the differences between the EA/IRMS and online LC/IRMS was ranged from 0.09‰ to 2.09‰. The eluent for LC was 5 mM sodium tetraborate decahydrate (pH=9.51). When the 1% phosphoric acid was not added, the oxidation potential of sodium peroxodisulfate was decreasing. Thus, when the eluent of alkalinity eluent was used, it is necessary to add phosphoric acid. However, the difference of 2 caffeine samples between EA/IRMS and online LC/IRMS without phosphoric acid and with phosphoric acid were 5.30‰ and 5.82‰, and 5.68‰ to 7.32‰, respectively. For caffeine samples, the δ13C did not change with or without phosphoric acid. Other reasons were considered e.g. incomplete combustion.

The effect of different cooking processes on stable C, N, and H isotopic compositions of beef.
Food chemistry (2015)
Jiuqing Zhou, Boli Guo, Yimin Wei, Guoquan Zhang, Shuai Wei, Yiyan Ma

The variability in the stable C, N, and H isotopic composition caused by different beef processing operations (boiling, frying, and roasting) was studied. The aim was to evaluate the stability of stable isotopic fingerprint information during the beef cooking process. The δ(13)C, δ(15)N, and δ(2)H values for raw, boiled, fried and roasted beef were measured, and the differences in the stable isotopic composition between raw and processed beef products were assessed. The results indicated that the δ(13)C and δ(15)N values in raw beef were not significantly different compared with processed beef, but the δ(2)H values were significantly higher in processed beef than in raw beef. In general, boiling, frying, and roasting had no significant effect on δ(13)C and δ(15)N values, but the δ(2)H value of processed beef increased.
Schlagworte: carbon , nitrogen , food , elem

Comparative study of ¹³C composition in ethanol and bulk dry wine using isotope ratio monitoring by mass spectrometry and by nuclear magnetic resonance as an indicator of vine water status.
Analytical and bioanalytical chemistry (2015)
Francois Guyon, Cornelis van Leeuwen, Laetitia Gaillard, Mathilde Grand, Serge Akoka, Gérald S Remaud, Nathalie Sabathié, Marie-Hélène Salagoïty

The potential of wine (13)C isotope composition (δ(13)C) is presented to assess vine water status during grape ripening. Measurements of δ(13)C have been performed on a set of 32 authentic wines and their ethanol recovered after distillation. The data, obtained by isotope ratio monitoring by mass spectrometry coupled to an elemental analyser (irm-EA/MS), show a high correlation between δ(13)C of the bulk wine and its ethanol, indicating that the distillation step is not necessary when the wine has not been submitted to any oenological treatment. Therefore, the ethanol/wine δ(13)C correlation can be used as an indicator of possible enrichment of the grape must or the wine with exogenous organic compounds. Wine ethanol δ(13)C is correlated to predawn leaf water potential (R(2) = 0.69), indicating that this parameter can be used as an indicator of vine water status. Position-specific (13)C analysis (PSIA) of ethanol extracted from wine, performed by isotope ratio monitoring by nuclear magnetic resonance (irm-(13)C NMR), confirmed the non-homogenous repartition of (13)C on ethanol skeleton. It is the δ(13)C of the methylene group of ethanol, compared to the methyl moiety, which is the most correlated to predawn leaf water potential, indicating that a phase of photorespiration of the vine during water stress period is most probably occurring due to stomata closure. However, position-specific (13)C analysis by irm-(13)C NMR does not offer a greater precision in the assessment of vine water status compared to direct measurement of δ(13)C on bulk wine by irm-EA/MS.
Schlagworte: carbon , food , elem

Provenancing Flower Bulbs by Analytical Fingerprinting: Convallaria Majalis
Agriculture (2015)
Saskia M van Ruth, Ries de Visser

The origin of agricultural products is gaining in appreciation while often hard to determine for various reasons. Geographical origin may be resolved using a combination of chemical and physical analytical technologies. In the present case of Lily of the Valley (Convallaria majalis) rhizomes, we investigated an exploratory set of material from The Netherlands, three other European (EU) countries and China. We show that the geographical origin is correlated to patterns of stable isotope ratios (isotope fingerprints) and volatile organic carbon (VOC) compounds (chemical fingerprints). These fingerprints allowed clear distinction using exploratory and supervised statistics. Isotope ratio mass spectrometry of 12C/13C, 14N/15N and 16O/18O isotopes separated materials from Europe and China successfully. The VOC patterns measured by Proton Transfer Reaction Mass Spectrometry (PTR-MS) allowed distinction of three groups: material from The Netherlands, the other EU countries and China. This knowledge is expected to help developing a systematic and efficient analytical tool for authenticating the origin of flower bulbs.
Schlagworte: carbon , nitrogen , oxygen , food , soil , elem

Photosynthetic diffusional constraints affect yield in drought stressed rice cultivars during flowering.
PloS one (2014)
Marco Lauteri, Matthew Haworth, Rachid Serraj, Maria Cristina Monteverdi, Mauro Centritto

Global production of rice (Oryza sativa) grain is limited by water availability and the low 'leaf-level' photosynthetic capacity of many cultivars. Oryza sativa is extremely susceptible to water-deficits; therefore, predicted increases in the frequency and duration of drought events, combined with future rises in global temperatures and food demand, necessitate the development of more productive and drought tolerant cultivars. We investigated the underlying physiological, isotopic and morphological responses to water-deficit in seven common varieties of O. sativa, subjected to prolonged drought of varying intensities, for phenotyping purposes in open field conditions. Significant variation was observed in leaf-level photosynthesis rates (A) under both water treatments. Yield and A were influenced by the conductance of the mesophyll layer to CO2 (g(m)) and not by stomatal conductance (g(s)). Mesophyll conductance declined during drought to differing extents among the cultivars; those varieties that maintained g(m) during water-deficit sustained A and yield to a greater extent. However, the variety with the highest g(m) and yield under well-watered conditions (IR55419-04) was distinct from the most effective cultivar under drought (Vandana). Mesophyll conductance most effectively characterises the photosynthetic capacity and yield of O. sativa cultivars under both well-watered and water-deficit conditions; however, the desired attributes of high g(m) during optimal growth conditions and the capacity for g(m) to remain constant during water-deficit may be mutually exclusive. Nonetheless, future genetic and physiological studies aimed at enhancing O. sativa yield and drought stress tolerance should investigate the biochemistry and morphology of the interface between the sub-stomatal pore and mesophyll layer.

Studies on the Authenticity of Local Wines by Spectroscopic and Chemometric Analysis
(2014)
Rebecca Kokkinofta, Naso Economidou, Eleni Tzioni, Katerina Damianou, Konstantina Poulli, Chara Savvidou, Charalambos Louka, Popi Kanari

The authenticity of 91 wines produced in Cyprus from both indigenous and other vine varieties were investigated by a holistic approach, using advanced technology such as SNIF-NMR (site-specific natural isotopic fractionation-nuclear magnetic resonance) and IR-MS (isotope ratio-mass spectrometry) for the determination of the stable isotopes and ICP (inductively coupled plasma spectroscopy) for some heavy metals. The spectroscopic characteristics were evaluated statistically using different chemometric methods. The dependency of the D/H (deuterium/hydrogen) ratio of the methylene site in the ethanol molecule (D/H)II and also the δ 18O values of the wine water, were the most useful discriminators. Isotopic results allow us to have a complete idea about the regional variability of the isotopes. Among the metals, Ni followed by Pb was the ones with the highest discrimination value. The determined concentrations of Pb, Ni, Cr and Cd that are related to the safety of wines were within the acceptable limits that have been established by the OIV (international organization of vine and wine) or comparable with the results of the wines of other European countries. The study of the correlation between the load of heavy metals and isotopes in wines showed a dependence on the grape variety but not the geographical location of the vineyard. This is probably due to the close proximity of wine regions in Cyprus.

Application des isotopes stables à l ’ authentification des vins au Service Commun des Laboratoires .
Société des Experts Chimistes de France (2014)
François Guyon, Laetitia Gaillard, Nathalie Sabathi, Bernard Medina, François Guillaume, Marie-hélène Salagoity

Stable isotope measurements allow various applications in wine such as authentication; they make possible the comparison between suspected and authentic wines. Using such techniques and the assistance of an isotopic data bank stemming from authentic samples, it is also possible to authenticate a sample even if the certified wine is not available. Moreover, researches are in progress to propose internal tags in order to assess wine authenticity elaborated in areas not covered by an isotopic data bank. Spectral analysis of wine profile obtained by 13C-NMR as well as the δ13C values of main components of a wine obtained by coupling IRMS with of liquid chromatography (HPLC or ion chromatography) are new pathways for wine authentication
Schlagworte: carbon , food , liqfac