TY - JOUR A1 - Mueller, Marina Elsa Herta A1 - Koszinski, Sylvia A1 - Brenning, Alexander A1 - Verch, Gernot A1 - Korn, Ulrike A1 - Sommer, Michael T1 - Within-field variation of mycotoxin contamination of winter wheat is related to indicators of soil moisture JF - Plant and soil N2 - Humidity is an important determinant of the mycotoxin production (DON, ZEA) by Fusarium species in the grain ears. From a landscape perspective humidity is not evenly distributed across fields. The topographically-controlled redistribution of water within a single field rather leads to spatially heterogeneous soil water content and air humidity. Therefore we hypothesized that the spatial distribution of mycotoxins is related to these topographically-controlled factors. To test this hypothesis we studied the mycotoxin concentrations at contrasting topographic relief positions, i.e. hilltops and depressions characterized by soils of different soil moisture regimes, on ten winter wheat fields in 2006 and 2007. Maize was the preceding crop and minimum tillage was practiced in the fields. The different topographic positions were associated with moderate differences in DON and ZEA concentrations in 2006, but with significant differences in 2007, with six times higher median ZEA and two times higher median DON detected at depression sites compared to the hilltops. The depression sites correspond to a higher topographic wetness index as well as redoximorphic properties in soil profiles, which empirically supports our hypothesis at least for years showing wetter conditions in sensitive time windows for Fusarium infections. KW - Wheat KW - Mycotoxins KW - Within-field variation KW - Topography KW - Humidity KW - Soil redoximorphic feature Y1 - 2011 U6 - https://doi.org/10.1007/s11104-010-0695-5 SN - 0032-079X SN - 1573-5036 VL - 342 IS - 1-2 SP - 289 EP - 300 PB - Springer CY - Dordrecht ER - TY - JOUR A1 - Haile, Mekbib Gebretsadik A1 - Kalkuhl, Matthias A1 - Algieri, Bernardina A1 - Gebreselassie, Samuel T1 - Price shock transmission BT - evidence from the wheat-bread market value chain in Ethiopia JF - Agricultural economics N2 - This study assesses the degree of vertical price transmission along the wheat-bread value chain in Ethiopia. This is pursued by applying a vector error correction model and an impulse response analysis using monthly price data for the period 2000-2015. Our analysis considers transmission of price shocks across different market levels, including from the international and domestic wheat grain markets at the upstream to the domestic wheat bread market at the downstream of the value chain. The empirical findings indicate that significant cointegration exists across prices of the different market stages. There is a transmission from international prices to domestic prices at downstream markets, in particular to flour and bread prices. Prices at upstream markets are largely influenced by the domestic wholesale market. In general, the speed of adjustment is quite slow with a half-life of about one year for restoring the equilibrium price relationship. As price margins between the different market stages in the value chain have substantially decreased in the last 15 years, higher transmission, and thus exposure to international market shocks, can be expected in the future. The results also show that causal relationships exist between prices at different market stageswith the wholesale market identified as the key market level where prices and price expectations are formed. KW - Q02 KW - Q11 KW - Q13 KW - L11 KW - M31 KW - Value chain KW - Price transmission KW - Impulse response KW - Wheat KW - Ethiopia Y1 - 2017 U6 - https://doi.org/10.1111/agec.12373 SN - 0169-5150 SN - 1574-0862 VL - 48 IS - 6 SP - 769 EP - 780 PB - Wiley CY - Hoboken ER - TY - JOUR A1 - Bönick, Josephine A1 - Huschek, Gerd A1 - Rawel, Harshadrai Manilal T1 - Determination of wheat, rye and spelt authenticity in bread by targeted peptide biomarkers JF - Journal of Food Composition and Analysis N2 - Adulteration of food and mislabeled products in global market is a major financial and reputational risk for food manufacturers and trade companies. Consequently, there is a necessity to develop analytical methods to meet these issues. An analytical strategy to check the authenticity of wheat, spelt and rye addition in bread products was developed based on database research, in silico digestion confirming peptide specificity and finally quantification by liquid chromatography-tandem mass spectrometry analysis. Peptide markers for wheat (SQQQISQQPQQLPQQQQIPQQPQQF; QQHQIPQQPQQFPQQQQF and QPHQPQQPYPQQ), spelt (ASIVVGIGGQ; SQQPGQIIPQQPQQPSPL) and rye (LPQSHKQHVGQGAL; AQVQGIIQPQQL and QQFPQQPQQSFPQQPQQPVPQQPL) were identified, verified by protein Basic Local Alignment Search Tool and database research and used for quantification in bread. The specific use of multi-reaction monitoring transitions of selected peptides permitted the identification of closely related species wheat and spelt. Other cereal species (emmer, einkorn, barley, maize, rye and oat) were also checked. The target peptides were quantified at different levels using own reference baked products (bread) after in-solution chymotryptic digestion. Sensitivity of the identification was 0.5-1% using flour-based (0-25%) matrix calibration and the analytical recovery in bread was 80-125%. The analytical strategy described here supplies an emerging, independent and flexible tool in controlling the labeling of bread. KW - Food analysis KW - Food composition KW - Food safety KW - Plant authentication KW - Wheat KW - Spelt KW - Rye KW - LC-MS-MS KW - Quantification of peptides KW - Food labeling Y1 - 2017 U6 - https://doi.org/10.1016/j.jfca.2017.01.019 SN - 0889-1575 SN - 1096-0481 VL - 58 SP - 82 EP - 91 PB - Elsevier CY - San Diego ER -