Different varieties of rice grown in various countries around the world (Australia, China P.R., France, India, Italy, Japan, Korea, Malaysia, Myanmar, Pakistan, Spain, Taiwan, Thailand, USA and Vietnam) were analysed using isotope ratio mass spectrometry and inductively coupled plasma mass spectrometry. The stable isotope ratios of carbon, nitrogen, oxygen and hydrogen and the multi-elemental compositions were assessed as variables for discrimination of the geographical origins of the rice samples. The data were processed by canonical discriminant analysis (CDA) enabling classification according to geographical origin. Fifteen key variables were identified by CDA as providing the maximum discrimination between the rice samples across different rice types and categorised on the basis of broad geographical areas (Asia, Australia, Europe, India and Pakistan, North America and Southeast Asia), enabling 90.7% correct classification for the model generated. This feasibility study demonstrated that the methodology has good potential in identifying the geographical origin for different rice types and useful as a database for the examination of unknown rice samples.
Rice samples cultivated in the USA, Europe and Basmati regions have been analysed using Isotope Ratio Mass Spectrometry (IRMS) and Inductively Coupled Plasma Mass Spectrometry (ICP-MS). Nine key variables (carbon-13, oxygen-18, boron, holmium, gadolinium, magnesium, rubidium, selenium and tungsten) were identified by canonical discriminant analysis as providing the maximum discrimination between rice samples from these regions. High levels of boron (>2500 ppb) were associated with rice samples from America and notably high levels of holmium were found in rice samples from the state of Arkansas. European rice samples generally contained relatively high levels of magnesium and Indian/Pakistani samples were characterised by relatively low oxygen-18 (18O) abundance.
The international measurement evaluation program (IMEP) has together with the European Reference Laboratory for Heavy Metals in Feed and Food (EU-RL-HM) carried out two interlaboratory comparisons (ILC) in 2010 on the measurement of trace metals, as well as methylmercury and inorganic arsenic in seafood. In IMEP-109 only EU National Reference Laboratories (NRL) took part, while IMEP-30 was open to all laboratories. In this article only methylmercury and inorganic arsenic analysis will be discussed, as these appear generally to be more problematic measurands. They are also particularly interesting to legislators, as no maximum limits have been set yet for them in European legislation. The aim of the two ILCs was to produce more information to help tackling this issue. The results of the two exercises were pooled together, evaluated, and compared with former ILC projects for methylmercury and inorganic arsenic analysis. Results for inorganic arsenic were spread, but not method dependant. The measurand seems to be difficult to analyse in this matrix and possible method issues were identified. Methylmercury results were satisfactory, but not many laboratories perform this type of analysis because it is generally believed that specific instrumentation is needed. As an answer to this presumption, alternatives are suggested.
As part of the European TRACE project (Tracing Food commodities in Europe, VI FP, Contract N. 006942), this paper provides a wide-ranging survey of the chemical composition of 571 mineral waters bottled and marketed in 23 European countries, and discusses 39 compositional parameters (specific electric conductivity, pH, hardness, total alkalinity, ammonia, chloride, fluoride, nitrate, nitrite, sulphate, Ca, K, Mg, Na, Al, B, Ba, Cd, Ce, Co, Cs, Cu, La, Li, Lu, Mn, Mo, Nd, Ni, Pb, Rb, Se, Sm, Sr, Tl, U, V, Yb, Zn) mainly referring to legal limits and nutritional implications. According to European legislation 58.1% of samples could be defined as ‘suitable for a low-sodium diet’ while 8.1% could be defined as ‘containing sodium’, 13.7% could be labelled as ‘containing magnesium’, 10.2% as ‘containing fluoride’, 4.9% as ‘containing chloride’, 13.5% as ‘containing sulphate’ and 17.5% as ‘containing calcium’. 2.8% of samples did not conform with European Community limits for at least one parameter (Se, NO2−, Mn, Ni, Ba, F and NO3−). About 9% of samples had boron, nitrate or nitrite levels above the legal limit existing in individual European countries.
The aim of this work (from the FP6 project TRACE) was to develop methods based on the use of geochemical markers for the authentication of the geographical origin of cereal samples in Europe (cf. EC regulations 2081/92 and 1898/06). For the first time, the potential usefulness of combining n(Sr-87)/n (Sr-86) and delta C-13, delta N-15, delta O-18 and delta S-34 isotopic signatures, alone or with key element concentrations ([Na], In [Ca], [Cu] and [Rb], progressively identified out of 31 sets of results), was investigated through multiple step multivariate statistics for more than 500 cereal samples collected over 2 years from 17 sampling sites across Europe representing an extensive range of geographical and environmental characteristics. From the classification categories compared (north/south; proximity to the Atlantic Ocean/to the Mediterranean Sea/to else; bed rock geologies) the first two were the most efficient (particularly with the ten variables selected together). In some instances element concentrations made a greater impact than the isotopic tracers. Validation of models included external prediction tests on 20% of the data randomly selected and, rarely done, a study on the robustness of these multivariate data treatments to uncertainties on measurement results. With the models tested it was possible to individualise 15 of the sampling sites. (C) 2010 Elsevier Ltd. All rights reserved.
H, C, and O stable isotope ratios and the elemental profile of 267 olive oils and 314 surface waters collected from 8 European sites are presented and discussed. The aim of the study was to investigate if olive oils produced in areas with different climatic and geological characteristics could be discriminated on the basis of isotopic and elemental data. The stable isotope ratios of H, C, and O of olive oils and the ratios of H and O of the relevant surface waters correlated to the climatic (mainly temperature) and geographical (mainly latitude and distance from the coast) characteristics of the provenance sites. It was possible to characterize the geological origin of the olive oils by using the content of 14 elements (Mg, K, Ca, V, Mn, Zn, Rb, Sr, Cs, La, Ce, Sm, Eu, U). By combining the 3 isotopic ratios with the 14 elements and applying a multivariate discriminant analysis, a good discrimination between olive oils from 8 European sites was achieved, with 95% of the samples correctly classified into the production site.
This paper presents the investigation of strontium isotope ratios of about 650 different European natural mineral waters as part of the food traceability project “TRACE” funded by the EU. Analysed 87Sr/86Sr values in the natural mineral waters range from 0.7035 to 0.7777, which indicates an influence by a great diversity of rocks from young mantle derived basaltic rocks to very old silicic continental crust.The results of the large scale investigation are used to elaborate a novel spatial prediction for strontium isotope ratios by combining the measured data with a GIS based geological map of Europe.The resulting map can be used to predict the strontium isotopic composition of groundwater and thus the composition of bio-available strontium, which is available for uptake by plants and subsequently transferred into the food chain. We also show, as an example, that the strontium isotopic composition of honey and wheat from specific sample regions within the TRACE project correlates well with that of the natural mineral water as predicted by our map.The proof of principle shown in our paper is highly relevant for geographical food authentication as it allows an assessment of the origin of food products without the immediate need for geographically authenticated materials which may not always be available. Our approach provides a cost effective first instance screening tool.