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• New possibilities to determine wheat quality parameters by near-infrared spectroscopy

  65-69

  Éva Kónya

  Zoltán Győri

  Views:

  155

  Analyses and methods in wheat quality determination require more sample, time, work and cost, thatswhy flour quality control needs rapid, reliable tools. Near-infrared spectroscopy has many advantages, which make it suitable in quality control. NIR instruments need calibrations to their work. In our study we examined gluten content, falling number, valorigrpahic waterabsorption, alveographic P/L and W value of wheat samples. Modified partial least squares analyses on NIR spectra were developed for each property. The results show that we got such calibration modells, which are able to predict the properties (expect falling number) with enough accuracy.

• Examination of wheat rheological characteristics by near-infrared spectroscopy

  99-104

  Éva Kónya

  Zoltán Győri

  Views:

  141

  Near-infrared spectroscopy has many advantages that make it a widely used analitical method in the different areas, like agricultural and food industry as well. In wheat quality control rheological characteristics of dough made from wheat flour are as important as physical and chemical properties too. In this work we examined rheological properties of wheat flour samples by alveograph, and spectral data of the same samples were collected by FOSS Infratec 1241 instrument. Modified partial least squares analyses on NIR spectra were developed for two alveograph parameter (P/L és W) to get calibration equations.

• Technological and Technical Issues of Efficient Nutrient Supply

  43-46

  Attila Kőkuti

  Views:

  62

  Efficient plant production requires modern production technologies, including a nutrient supply of a scientific basis. The harmonic nutrient supply of quality products that are required by market demands can be produced by the optimal combination of a compound system of requirements. These requirements are partly preparatory (soil investigations, yield measurements, preparation of digital field maps) and are partly based on the knowledge of the most significant characteristics of the applied nutrients. Most artificial fertilizers are applied by spinning disc fertilizer spreaders all over the world, therefore, it is advisable to use them in Hungary as well. Importantly, these machines should be well adjustable, capable of the exact measurement and control of the spread quantity, as well as of even spreading. My report has investigated only the most significant technical requirements affecting the even application of nutrients.

• Preliminary Critical P-limit Values of 0.01 M CaCl2 Soil Test Procedure

  18-21

  István Jászberényi

  Jakab Loch

  Views:

  108

  In the last decade, the 0.01 M CaCl₂ extraction procedure was tested as a multi-nutrient extractant. In 1995-97, international joint research activities were carried out within the COPERNICUS project. Detailed calibration of conventional and the 0.01 M CaCl₂ extraction procedures for pH, Mg and K were published.
  The amount of phosphorus extracted using a 0.01 M CaCl₂ solution is very low and reflects the intensity parameter of phosphorus bio-availability. As a readily desorbed P fraction of soils can reflect the soil P-supply and the CaCl₂-P values are in close correlation with P-fertiliser rates and P balance. However, the effects of various soil characteristics on CaCl₂-P values are different and their interpretation is difficult.
  Relatively poor correlations were found between amounts of P extracted by conventional and CaCl₂ soil test methods and, therefore, P limit values could not be calculated directly. To characterise the soil P supply at different sites, the CaCl₂ desorbed P and the adsorbed P in a modified Baker Soil Test were also applied.
  Soil test results of Hungarian long-term fertiliser experiments and recommended CaCl₂-P limit values, calculated on yield effects and soil characteristics, are discussed.

• Determination of the validation parameters of inductively coupled plasma mass spectrometer (iCP-mS): response curve linearity in the case of arsenic and selenium

  67-71

  Dávid Andrási

  Béla Kovács

  Views:

  148

  In the field of elemental analysis inductively coupled plasma mass spectrometers (ICP-MS) have the best sensitivity that means the lowest limit of detection, subsequently their applicability for the detection of essential and toxic elements in foods and foodstuffs is prominent. For the most elements could be measured the detection limit is between μg kg^-1 (ppb) and ng kg^-1 (ppt) e.g. for arsenic and selenium.

  Considering an analytical task (sample type, analytes and their concentration, pretreatment procedure etc.) the applicability of an analytical method is determined by its performance characteristics. The purpose of validation is to ensure that the method would be used fulfills the requirements of the given task. In this article we describes one of the performance characteristics, the linearity, and the whole validation procedure aims measurement of arsenic and selenium in foodstuffs by inductively coupled plasma mass spectrometer (Thermo XSeries I.); but because of the limited number of pages the results are demonstrated only for arsenic.

  The linearity of calibration was evaluated in three concentration ranges (0.1–1 μg l^-1; 1–10 μg l^-1; 10–50 μg l^-1), with nine line-fit possibilities (without weighting, weighting with absolute or relative deviation; with or without forcing the curve through blank or origin) and different methods (graphical examination, correlation coefficient, analysis of variance).

  The best method to ensure the linearity of correspondence between signal and concentration was the ANOVA test. In view of calibrations it was found that the range of 10–50 μg l-1 could be regarded as linear with four line-fit possibilities, and was non-linear between 0.1–1 μg l^-1 and 1–10 μg l^-1.

• Quality analysis of the near-infrared spectra of wheat samples

  97-100

  Éva Kónya

  Géza Kovács

  Zoltán Győri

  Views:

  139

  The near infrared spectroscopy is widely used in the different industries as a rapid, non-invasive analitical tool. It is suitable for identification, qualification and quantitative analysis as well. As this technique is indirect, to make accurate calibration equations we need a proper sample population. Before the quantitaive analysis, developing calibiration modells we have to collect and examine the spectra. In our study we examined wheat samples with known origins to find if there is any effect of the growing area on the NIR spectra.