Fingerprint analysis of biological samples using ICP-MS and IR-MS

Atomic spectroscopy based analytical techniques can generate fingerprints encompassing the vast majority of elements found in the periodic table as well as ratios of their stable isotopes. These highly multivariate fingerprints have laid the foundation of many recent studies within environmental, geological, agricultural and food science. Inductively coupled plasma-optical emission spectroscopy (ICP-OES) and ICP-mass spectrometry (ICP-MS) still dominate multi-elemental analyses of biological samples while stable isotopes of the light mass elements H, C, N, O and S are measured by isotope ratio-mass spectrometry (IR-MS). However, it has recently been shown that rather unexplored analytical methods such as semi-quantitative ICP-MS and compound-specific isotope analysis (CSIA) can generate novel information suitable for evaluating the authenticity of plant based food products (1-3). Most plant based studies using atomic spectroscopy have focused on the essential nutrients: B, Mg, P, S, K, Ca, Mn, Fe, Ni, Cu, Zn, Mo and selected heavy metals such as Cd and Pb (4). However, plants contain traces of most of the periodic table, which can be measured by semi-quantitative ICP-MS (1-2). This represents a fast method for elemental fingerprinting in the mass range 7Li to 238U, but the accuracy suffers from the simplified calibration procedure that this technique is based on. The combination of semi-quantitative ICP-MS and multivariate statistics (chemometrics) efficiently minimize this problem and constitute a promising tool for authentication of plant products according to their geographical origin and production form (2). Stable isotope analysis complements elemental fingerprinting by targeting specific biological processes and their impact on the isotopic plant composition. This has recently proven valuable for authenticating organically grown plant products – especially when focusing on selected isotope pairs in plant derived compounds such as 18O/16O in NO3- using CSIA (3). Cases of novel atomic spectroscopy based food authentications will be presented at the conference

Sensationslyst bag påstand om økologiske produkter

Sensationslyst bag påstand om økologiske produkter

Økologi og sundhed - videnskab eller ønsketænkning?

Økologi og sundhed - videnskab eller ønsketænkning

AuthenticFood

A presentation of the CORE Organic II project AuthenticFood

Recent developments in fast spectroscopy for plant mineral analysis

Ideal fertilizer management to optimize plant productivity and quality is more relevant than ever, as global food demands increase along with the rapidly growing world population. At the same time, sub-optimal or excessive use of fertilizers leads to severe environmental damage in areas of intensive crop production. The approaches of soil and plant mineral analysis are briefly compared and discussed here, and the new techniques using fast spectroscopy that offer cheap, rapid, and easy-to-use analysis of plant nutritional status are reviewed. The majority of these methods use vibrational spectroscopy, such as visual-near infrared and to a lesser extent ultraviolet and mid-infrared spectroscopy. Advantages of and problems with application of these techniques are thoroughly discussed. Spectroscopic techniques considered having major potential for plant mineral analysis, such as chlorophyll a fluorescence, X-ray fluorescence, and laser-induced breakdown spectroscopy are also described

The biochemical properties of manganese in plants

Manganese (Mn) is an essential micronutrient with many functional roles in plant metabolism. Manganese acts as an activator and co-factor of hundreds of metalloenzymes in plants. Because of its ability to readily change oxidation state in biological systems, Mn plays and important role in a broad range of enzyme-catalyzed reactions, including redox reactions, phosphorylation, decarboxylation, and hydrolysis. Manganese(II) is the prevalent oxidation state of Mn in plants and exhibits fast ligand exchange kinetics, which means that Mn can often be substituted by other metal ions, such as Mg(II), which has similar ion characteristics and requirements to the ligand environment of the metal binding sites. Knowledge of the molecular mechanisms catalyzed by Mn and regulation of Mn insertion into the active site of Mn-dependent enzymes, in the presence of other metals, is gradually evolving. This review presents an overview of the chemistry and biochemistry of Mn in plants, including an updated list of known Mn-dependent enzymes, together with enzymes where Mn has been shown to exchange with other metal ions. Furthermore, the current knowledge of the structure and functional role of the three most well characterized Mn-containing metalloenzymes in plants; the oxygen evolving complex of photosystem II, Mn superoxide dismutase, and oxalate oxidase is summarized

Forskere forebygger økosvindel

En stigende efterspørgsel på økologiske fødevarer har i de senere år medført madforfalskning og snyd. Nu vil et europæisk forskningsprojekt med Det Natur- og Biovidenskabelige Fakultet ved Københavns Universitet i spidsen udvikle metoder, der både kan afsløre fødevarens geografiske oprindelse, og om den er økologisk eller ej

AuthenticFood - Fast methods for authentication of organic plant based foods

Novel analytical methods for authenticating organic plant products

SE-ENRICHMENT OF CARROT AND ONION VIA FOLIAR APPLICATION

The aim of this work was to study the selenium accumulation in carrot and onion plants using foliar application by sodium selenite and sodium selenate. Furthermore, we aimed at identifying the Se species biosynthesised by onion and carrot plants. The results were used to prepare for production of 77Se enriched plants for an ongoing human absorption study

Identification of manganese efficiency candidate genes in winter barley (<i>Hordeum vulgare</i>) using genome wide association mapping

BACKGROUND: Manganese (Mn) has several essential functions in plants, including a role as cofactor in the oxygen evolving complex (OEC) of photosystem II (PSII). Manganese deficiency is a major plant nutritional disorder in winter cereals resulting in significant yield reductions and winter kill in more severe cases. Among the winter cereals, genotypes of winter barley are known to differ considerably in tolerance to Mn deficiency, but the genes controlling the Mn deficiency trait remains elusive. RESULTS: Experiments were conducted using 248 barley varieties, cultivated in six distinct environments prone to induce Mn deficiency. High-throughput phenotyping for Mn deficiency was performed by chlorophyll a (Chl a) fluorescence analysis to quantify the quantum yield efficiency of PSII. High-throughput phenotyping in combination with ICP-OES based multi-element analyses allowed detection of marker-trait associations by genome wide association (GWA) mapping. Several key candidate genes were identified, including PSII subunit proteins, germin like proteins and Mn superoxide dismutase. The putative roles of the encoded proteins in Mn dependent metabolic processes are discussed. CONCLUSIONS: Fifty-four candidate genes were identified by Chl a fluorescence phenotyping and association genetics. Tolerance of plants to Mn deficiency, which is referred to as Mn efficiency, appeared to be a complex trait involving many genes. Moreover, the trait appeared to be highly dependent on the environmental conditions in field. This study provides the basis for an improved understanding of the parameters influencing Mn efficiency and is valuable in future plant breeding aiming at producing new varieties with improved tolerance to cultivation in soil prone to induce Mn deficiency. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1186/s12864-016-3129-9) contains supplementary material, which is available to authorized users