Multi-isotopic signatures of organic and conventional Italian pasta along the production chain.

The variability of stable isotope ratios (δ(2) H, δ(13) C, δ(15) N, δ(18) O and δ(34) S) along the production chain of pasta (durum wheat, flour and pasta) produced by using both conventional and organic farming systems in four Italian regions in 2 years was investigated. The aim was to evaluate if and how the farming system and geographical origin affect stable isotope ratios determined along the production chain. Irrespective of the processing technology, 65% of the samples were correctly classified according to the farming system and 98% were correctly classified regarding the geographical region. When considering both farming system and geographical region simultaneously, 80% of the samples were correctly classified. The measured isotope parameters were thus primarily affected by the geographical origin. In conclusion, it is expected that the use of these parameters will allow the development of analytical control procedures that can be used to check the geographical origin of Italian organic and conventional pasta and its raw materials. Copyright © 2016 John Wiley & Sons, Ltd.

Multi-platform metabolomics analyses of a broad collection of fragrant and non-fragrant rice varieties reveals the high complexity of grain quality characteristics.

The quality of rice in terms not only of its nutritional value but also in terms of its aroma and flavour is becoming increasingly important in modern rice breeding where global targets are focused on both yield stability and grain quality. In the present paper we have exploited advanced, multi-platform metabolomics approaches to determine the biochemical differences in 31 rice varieties from a diverse range of genetic backgrounds and origin. All were grown under the specific local conditions for which they have been bred and all aspects of varietal identification and sample purity have been guaranteed by local experts from each country. Metabolomics analyses using 6 platforms have revealed the extent of biochemical differences (and similarities) between the chosen rice genotypes. Comparison of fragrant rice varieties showed a difference in the metabolic profiles of jasmine and basmati varieties. However with no consistent separation of the germplasm class. Storage of grains had a significant effect on the metabolome of both basmati and jasmine rice varieties but changes were different for the two rice types. This shows how metabolic changes may help prove a causal relationship with developing good quality in basmati rice or incurring quality loss in jasmine rice in aged grains. Such metabolomics approaches are leading to hypotheses on the potential links between grain quality attributes, biochemical composition and genotype in the context of breeding for improvement. With this knowledge we shall establish a stronger, evidence-based foundation upon which to build targeted strategies to support breeders in their quest for improved rice varieties.

Is it really organic?--multi-isotopic analysis as a tool to discriminate between organic and conventional plants.

Novel procedures for analytical authentication of organic plant products are urgently needed. Here we present the first study encompassing stable isotopes of hydrogen, carbon, nitrogen, oxygen, magnesium and sulphur as well as compound-specific nitrogen and oxygen isotope analysis of nitrate for discrimination of organically and conventionally grown plants. The study was based on wheat, barley, faba bean and potato produced in rigorously controlled long-term field trials comprising 144 experimental plots. Nitrogen isotope analysis revealed the use of animal manure, but was unable to discriminate between plants that were fertilised with synthetic nitrogen fertilisers or green manures from atmospheric nitrogen fixing legumes. This limitation was bypassed using oxygen isotope analysis of nitrate in potato tubers, while hydrogen isotope analysis allowed complete discrimination of organic and conventional wheat and barley grains. It is concluded, that multi-isotopic analysis has the potential to disclose fraudulent substitutions of organic with conventionally cultivated plants.

Multielement plant tissue analysis using ICP spectrometry.

Plant tissue analysis is a valuable tool for evaluating the nutritional status and quality of crops and is widely used for scientific and commercial purposes. The majority of plant analyzes are now performed by techniques based on ICP spectrometry such as inductively coupled plasma-optical emission spectroscopy (ICP-OES) or ICP-mass spectrometry (ICP-MS). These techniques enable fast and accurate measurements of multielement profiles when combined with appropriate methods for sample preparation and digestion. This chapter presents state-of-the-art methods for digestion of plant tissues and subsequent analysis of their multielement composition by ICP spectrometry. Details on upcoming techniques, expected to gain importance within the field of multielement plant tissue analysis over the coming years, are also provided. Finally, attention is given to laser ablation ICP-MS (LA-ICP-MS) for multielement bioimaging of plant tissues. The presentation of the methods covers instructions on all steps from sampling and sample preparation to data interpretation.

ICP-MS and LC-ICP-MS for analysis of trace element content and speciation in cereal grains.

Trace elements are unevenly distributed and speciated throughout the cereal grain. The germ and the outer layers of the grain have the highest concentrations of trace elements. A large fraction of the trace elements is therefore lost during the milling process. The bioavailability of the remaining trace elements is very low. This is usually ascribed to the formation of poorly soluble complexes with the phosphorus storage compound phytic acid. Hence, analysis of the total concentration of trace elements in grain tissues must be combined with a speciation analysis in order to assess their contribution to human nutrition. This chapter deals with the fractionation of anatomically very different cereal tissues. Procedures for microscaling of digestion procedures are outlined together with requirements for the use of certified reference materials in elemental profiling of grain tissue fractions. Methods for extraction and analysis of complexes containing trace elements in the grain tissue fractions are described. Finally, the chapter concludes with criteria for choice of chromatographic methods and setting of ICP-MS instrument parameters.