Authors:M. Sabo, M. Sabo, D. Jug, D. Jug, Ž. Ugarčić-Hardi, and Ž. Ugarčić-Hardi
The effect of tillage systems (TS) on wheat quality traits including grain yield, thousand-kernels weight, hectoliter mass, flour extraction rate and flour rheological properties were evaluated. Five different TS were compared in winter wheat (Triticum aestivum L.) production on one experimental field (chernosem) located in the Baranya region, north-eastern Croatia from 1998 to 2001. Tillage systems included conventional tillage (CT), disc harrowing, fine till (DHF), soil loosening (SL) + disc harrowing (DH), disc harrowing, coarse till (DHC) and no-tillage (NT). The most stable grain yield was obtained by DHF and CT in all three experimental years. There was no striking regularity with regard to applied TS and hectoliter mass and thousand-kernels weight. The biggest difference of hectoliter mass was determined between CT and NT. TS had significant influence on the flour extraction rate in all three experimental years. The influence of TS on farinographic parameters was significant for all three experimental years for the quality number. Quality number was greater under CT than under other TS. Tillage effect on extensographic and amylographic parameters in the 3-year average did not show statistically significant differences. To sum up, since disc harrowing (DHF) and (DHC) followed by soil loosening with chisel produced equal grain yield and wheat quality parameters were slightly better than conventional tillage, these systems could be presented as an even handed replacement for ploughing.
Potentially toxic metals in the food chain that can lead to deleterious effects on human health have been well documented.
Because of the toxicity of some metals, levels of 1 ppm or less must be routinely monitored in foods to ensure human safety.
To ensure the accuracy of measurement, NBS in a cooperative interagency agreement with the Food and Drug Administration is
involved in developing and certifying selected elements in food grain as a part of the Standard Reference Material program.
Both instrumental and radiochemical neutron activation analysis were used to analyze two food grain standard reference materials
(Rice and Wheat Flours) for trace element certification.
Authors:R. Dybczyński, H. Maleszewska, and M. Wasek
Distribution coefficients of 14 elements between LIX 70 in toluene and aqueous 1M NaNO3 solution containing varying concentrations of HCl or suitable buffer, respectively, were determined by batch equilibration. It was shown that very selective separation of Cu from other elements can be achieved on columns with LIX 70 supported on Bio-Beads SM-1. Highly accurate and precise method for the determination of trace amounts of Cu in biological materials was devised by combining NAA with extraction chromatography. Results of copper determination in NBS 1570 /Spinach/, IAEA H-4 /Animal muscle/ and IAEA V-8 /Rye flour/ are presented.
An automated post-irradiation chemical separation scheme for the analysis of 14 trace elements in biological materials is
described. The procedure consists of a destruction with sulfuric acid and hydrogen peroxide, a distillation of the volatile
elements with hydrobromic acid and chromatography of both distillate and residue over Dowex 2X8 anion exchanger columns. Accuracy,
precision and sensitivity are tested with reference materials (BOWEN’s kale, NBS bovine liver, IAEA materials dried animal
whole blood, wheat flour, dried potatoes, powdered milk, oyster homogenate) and on a sample of pooled human blood. Blank values
due to trace elements in the quartz irradiation vials are also discussed.
The use of dataloggers in food engineering is discussed in two examples. The first example describes the measurement of temperature and humidity in a bulk tank car during transport and unloading. In the case of wheat flour the relative humidity in the air raises from about 80% r.h. to values near 100% r.h. at the air compressors for pneumatical unloading start working. The second example shows the use of the datalogger in education on heat transfer. The device was fixed in an ice cream sample which was placed in a store at –25°C. The measured hardeningtime agrees well to theoretical heat transfer calculation.
Instrumental neutron activation analysis was applied to the determination of the elements Na, K, Br, As, Rb, Zn, Co, Fe and Sc in Brazilian rice samples and in biological standards. Hg and Se concentrations were determined by using a simple radiochemical separation. The chemical procedure was carried out by means of distillation of Hg and Se in HBr medium and subsequent precipitation of selenium by sodium metabisulfite and mercury by thioacetamide. The accuracy of the instrumental and radiochemical methods was evaluated by means of analysis of the Reference Materials NBS-Bovine Liver, Bowen's Kale and NBS-Rice Flour.