Charakterisierung von Getreide aus ökologischem und konventionellem Anbau - Anwendung von Protein-Profiling-Techniques und Inhaltsstoffanalysen

Ökologisch und konventionell angebauter Weizen aus dem kontrollierten DOK-Feldversuch (Schweiz) wurde umfassend hinsichtlich biochemischer Unterschiede charakterisiert. Dazu wurden die Profiling-Techniken Proteomics und Metabolomics, sowie Analytik von Einzelverbindungen eingesetzt. Metaboliten-Profile und Analytik von Einzelverbindungen ergaben geringfügige Unterschiede im DOK-Weizen aus unterschiedlichen Anbauvarianten. Statistisch signifikante Abweichungen konnten meist nur für eines von zwei untersuchten Anbaujahren gefunden werden. Abweichungen lagen innerhalb der bekannten Schwankungsbreiten bei Weizen. Beim Protein-Profiling, durchgeführt mit zweidimensionaler Gel-Elektrophorese, Bildauswertung und Proteinidentifizierung wurden die relativen Gehalte von ca. 1000 Proteinen in Weizen bestimmt. Die Gehalte von 16 Proteinen waren in ökologischem und konventionellem Weizen aus zwei Anbaujahren signifikant verschieden. Diese 16 Proteine bilden eine Signatur, anhand derer die Anbauvarianten des DOK-Weizens unterschieden werden können. In einem nächsten Schritt soll untersucht werden, ob diese Signatur gleichfalls bei ökologischem und konventionellem Weizen gilt, der von verschiedenen Standorten und von verschiedenen Sorten stammt. Vor dem Hintergrund des komplexen Gesamtstoffwechsels von Pflanzen ergeben die relativ wenigen mit verschiedenen Gehalten auftretenden Proteine keinen Hinweis auf Änderungen von Stoffwechselaktivitäten, die für die menschliche Ernährung kritisch wären. Die signifikante Reduzierung des Gesamtproteingehalts ist unter Ernährungsgesichtspunkten eher ungünstig, bei der in Deutschland üblichen Zusammensetzung der Diät aber unbedenklich. Zusammenfassend wird mit Blick auf die Ergebnisse des Protein-Profiling, des Metaboliten-Profiling und der Analytik von Einzelverbindungen gefolgert, dass ökologischer und konventioneller DOK-Weizen hinsichtlich der untersuchten Parameter ernährungsphysiologisch gleich wertvoll ist

Free sugars in spelt wholemeal and flour

Spelt (Triticum aestivum L. ssp. spelta) is experiencing a renaissance in Europe and North America, where it is used for baking, brewing, production of pasta, and self-supplied animal feed. One of the characteristics of spelt is that in comparison to modern wheat it is more resistant to harsh climatic and poor soil conditions. In contrast to wheat the hulls remain on the grain after threshing. Drawbacks are that spelt yields are quite low compared to modern wheat. The subject of the current study was to gain information about the composition of soluble sugars and their concentrations in spelt wholemeal and flour. High performance liquid chromatography (HPLC) was used for analysis. Concentrations of nine free sugars in spelt wholemeal and flour are reported. Flour cumulative free sugar concentrations were 63% lower than in wholemeal. For comparisons, we also analyzed wholemeal of wheat. The cumulative concentration of free sugars was 27% lower than in spelt wholemeal. However, when published data for sugar concentration ranges of wheat are taken into account, the total concentration of free sugar was not different between spelt and modern wheats. Low concentrations of xylose and stachyose were detected in spelt. Higher concentrations of fructans such as 1-kestose and kestotetraose were detected in spelt when compared with wheat. Generally, concentrations of free sugars in spelt were in the range of free sugar levels published for wheat, except for maltose which was higher in spelt

Nutritional quality of organic and conventional wheat

The popularity of organic food and the farming area managed according to organic agriculture practices have been increasing during the last years. It is not clear, whether foods from organic and conventional agriculture are equal with respect to nutritional quality. We chose wheat (Triticum aestivum L., cv. Titlis) as one of the most important crop plants to determine a range of substances relevant for human nutrition in crops from organic and conventional agriculture systems. Wheat grains of 2003 originating from a long term field experiment, the Swiss DOK trial, consisting of bio-dynamic, bio-organic and conventional farming systems were used. Thousand seed weight, protein content, phosphate levels, antioxidative capacity, levels of phenols, fibre, fructan, oxalate and phytic acid were determined in whole wheat meal from the various organic and conventional growing systems of the DOK trial. Levels of these substances fell into a range that is known to occur in other wheat crops, indicating that wheat from the DOK trial was not special. Clearcut differences were observed for none-fertilised wheat, which was significantly lowest in thousand seed weight, protein and significantly highest in total oxalate. For the majority of the nutritionally important substances analysed, there were no significant differences between bio-dynamic, bio-organic, and conventional growing systems. Only protein content and levels of fibres were statistically different. Taken together, the magnitude of observed variations was very small. The results of our investigations do not provide evidence that wheat of one or the other agriculture system would be better or worse

Exploring CEvNS with NUCLEUS at the Chooz Nuclear Power Plant

Coherent elastic neutrino-nucleus scattering (CE$\nu$NS) offers a unique way to study neutrino properties and to search for new physics beyond the Standard Model. Nuclear reactors are promising sources to explore this process at low energies since they deliver large fluxes of (anti-)neutrinos with typical energies of a few MeV. In this paper, a new-generation experiment to study CE$\nu$NS is described. The NUCLEUS experiment will use cryogenic detectors which feature an unprecedentedly low energy threshold and a time response fast enough to be operated in above-ground conditions. Both sensitivity to low-energy nuclear recoils and a high event rate tolerance are stringent requirements to measure CE$\nu$NS of reactor antineutrinos. A new experimental site, denoted the Very-Near-Site (VNS) at the Chooz nuclear power plant in France is described. The VNS is located between the two 4.25 GW$_{\mathrm{th}}$ reactor cores and matches the requirements of NUCLEUS. First results of on-site measurements of neutron and muon backgrounds, the expected dominant background contributions, are given. In this paper a preliminary experimental setup with dedicated active and passive background reduction techniques is presented. Furthermore, the feasibility to operate the NUCLEUS detectors in coincidence with an active muon-veto at shallow overburden is studied. The paper concludes with a sensitivity study pointing out the promising physics potential of NUCLEUS at the Chooz nuclear power plant

Results on MeV-scale dark matter from a gram-scale cryogenic calorimeter operated above ground

Models for light dark matter particles with masses below 1 GeV/c$^2$ are a natural and well-motivated alternative to so-far unobserved weakly interacting massive particles. Gram-scale cryogenic calorimeters provide the required detector performance to detect these particles and extend the direct dark matter search program of CRESST. A prototype 0.5 g sapphire detector developed for the $\nu$-cleus experiment has achieved an energy threshold of $E_{th}=(19.7\pm 0.9)$ eV, which is one order of magnitude lower than previous results and independent of the type of particle interaction. The result presented here is obtained in a setup above ground without significant shielding against ambient and cosmogenic radiation. Although operated in a high-background environment, the detector probes a new range of light-mass dark matter particles previously not accessible by direct searches. We report the first limit on the spin-independent dark matter particle-nucleon cross section for masses between 140 MeV/c$^2$ and 500 MeV/c$^2$.Comment: 6 pages, 6 figures, v3: ancillary files added, v4: high energy spectrum (0.6-12keV) added to ancillary file

Limits on Dark Matter Effective Field Theory Parameters with CRESST-II

CRESST is a direct dark matter search experiment, aiming for an observation of nuclear recoils induced by the interaction of dark matter particles with cryogenic scintillating calcium tungstate crystals. Instead of confining ourselves to standard spin-independent and spin-dependent searches, we re-analyze data from CRESST-II using a more general effective field theory (EFT) framework. On many of the EFT coupling constants, improved exclusion limits in the low-mass region (< 3-4 GeV) are presented.Comment: 7 pages, 9 figure

First results from the CRESST-III low-mass dark matter program

The CRESST experiment is a direct dark matter search which aims to measure interactions of potential dark matter particles in an earth-bound detector. With the current stage, CRESST-III, we focus on a low energy threshold for increased sensitivity towards light dark matter particles. In this manuscript we describe the analysis of one detector operated in the first run of CRESST-III (05/2016-02/2018) achieving a nuclear recoil threshold of 30.1eV. This result was obtained with a 23.6g CaWO$_4$ crystal operated as a cryogenic scintillating calorimeter in the CRESST setup at the Laboratori Nazionali del Gran Sasso (LNGS). Both the primary phonon/heat signal and the simultaneously emitted scintillation light, which is absorbed in a separate silicon-on-sapphire light absorber, are measured with highly sensitive transition edge sensors operated at ~15mK. The unique combination of these sensors with the light element oxygen present in our target yields sensitivity to dark matter particle masses as low as 160MeV/c$^2$.Comment: 9 pages, 9 figure

TES-Based Light Detectors for the CRESST Direct Dark Matter Search

The CRESST experiment uses cryogenic detectors based on transition-edge sensors to search for dark matter interactions. Each detector module consists of a scintillating CaWO₄ crystal and a silicon-on-sapphire (SOS) light detector which operate in coincidence (phonon-light technique). The 40-mm-diameter SOS disks (2 g mass) used in the data taking campaign of CRESST-II Phase 2 (2014–2016) reached absolute baseline resolutions of σ = 4–7 eV. This is the best performance reported for cryogenic light detectors of this size. Newly developed silicon beaker light detectors (4 cm height, 4 cm diameter, 6 g mass), which cover a large fraction of the target crystal surface, have achieved a baseline resolution of σ = 5.8 eV. First results of further improved light detectors developed for the ongoing low-threshold CRESST-III experiment are presented. Keywords: Transition-edge sensor; Cryogenic light detector; Direct dark matter searc