Authors:R. Rao, L. McDowell, C. Jayawickreme, and A. Chatt
The homogeneity of four reference materials was evaluated for Se by cyclic instrumental neutron activation analysis (CINAA). The relative standard deviation for Se measurements at ppb levels by CINAA was <12% for NIST Wheat Flour (SRM 1567) in 5–10 mg samples, while it was <11% for Chinese Hair (HH–CH-1), <13% for IAEA Animal Muscle (H-4) and 25% for IAEA Animal Blood (A-13) in 50 mg samples. The highest relative subsampling uncertainties were observed in the mass range of samples 50 mg for Chinese Hair, 100 mg for Wheat Flour and Animal Muscle and 300 mg for Animal Blood. The results of a one-way analysis of variance indicate that all reference materials above these mass ranges are adequately homogeneous with respect to Se distribution. Our data suggest that these materials, except Animal Blood, can be used as reference standards for Se in Quality assurance programs well below the sample masses re commended by the issuing agencies.
Eckert, B., Amend, T., Belitz, H.-D. 1994: What is unique about wheat gluten? Microscopic observations on flour particles of various cereals. pp. 498-504. In: Gluten Proteins 1993. Association of Cereal Research, Detmold, Germany
A simple method for the determination of sub ppm amounts of mercury in various biological materials by neutron activation
analysis is described. Irradiated samples were decomposed with H2SO4-fuming HNO3 mixture and mercury selectively isolated by ion exchange chromatography using Dowex 50WX2 [H+] and Dowex 1X4 [Br−] columns in HBr medium. Finally the activity of197Hg fixed on an anion exchange resin was measured either with a Ge(Li) or a NaI (Tl) detector. Both the high radiochemical
purity of mercury and the practically quantitative recovery were achieved thus eliminating the necessity of determining the
chemical yield. The method was used for the determination of mercury in flour, milk, butter, margarine, fish, etc.
Following up transfer of strontium from soil to plants requires determination of isotope in the surface layer of soil and
a chosen plant. The most endangered food products are plants including commonly grown grain, which constitutes a basic feeding
component for both people and animals. Indeed large amounts of 137Cs, 90Sr get into organisms of people and animals with the food, therefore determination of radioactivity of elements in food products
and animal fodder is very essential. Choice of proper diet allows to limit the level of human organism denaturation. The aim
of this paper was to study relocation of 90Sr, 137Cs, 40K isotopes from soil to grain and then from grain to food products. There were investigated soil, wheat, barley, groats, flour,
macaroni and breakfast flakes. Based on the obtained results there were calculated effective weighted doses [nSv] from consumption
of 1 kg of a product for different age groups.
Implementation of sourdough technology would increase nutritional value and attractiveness of gluten-free bread. However, fermentation process requires stimulation. The course of fermentation of gluten-free sourdoughs prepared from maize and soy flours and maize and potato starches, enriched in glucose and casein hydrolysate or soy sprouted seeds used as fermentation enhancers was evaluated. The clearest effect of the supplementation was observed in the case of sourdough prepared from starches only. The addition of glucose in the amounts as low as 0.5% has proved to be enough to enhance fermentation effectively. Supplementation of the sourdoughs with peptides was not very effective; however, when used together with glucose, a synergistic effect could be detected. The addition of sprouted seeds allowed to shorten the fermentation process with up to several hours. These studies have demonstrated possibility to simplify and shorten the process of gluten-free sourdough fermentation by modification of mixtures composition.
Bread is one of basic human dietary items. Bread products commercially available usually contain flour, water, yeast or sourdough, and numerous functional additives, among them inorganic chlorides (mainly NaCl), phosphates, and sulphates, modifying physicochemical properties of final products to be attractive for consumers. Various kinds (whole-wheat, rye, and wheat rye) of Polish commercial breads were examined for contents of chlorides, phosphates, and sulphates by combination of water extraction and ion chromatography with conductometric detection. The evaluated amounts of the analytes corresponded to 0.58–1.06 g of chlorides (1–1.8 g NaCl), 100–300 mg of phosphates, and 10–130 mg of sulphates in 100 g (ca. two slices) of bread, which means that bread can be an important source of inorganic ions for humans, in particular in case of high consumption.
Authors:A. Nagy, Á. Baráth, J. Pauk, and É. Gelencsér
The authors have developed transgenic wheat lines with broad range of herbicide resistance. The transgenic wheat, containing bacterial derived alien gene (bar) regulated under the maize ubiquitin promoter, is resistant to glyphosinate (phosphinotrichin) agent family. The presence of bar gene expression product (phosphinotrichin acetyl transpherase enzyme, PAT) was confirmed by PAT-specific ELISA (Enzyme Linked Immuno Sorbent Assay). The qualitative and quantitative chemical composition of the transgenic wheat lines in comparison with their non-transgenic counterpart (year 2000-2002) and protein utilization of the wheat wholemeal flours (year 2002) were summarized. Nutritional evaluation of the protein was based on a rat model by using N-balance experiments. Among the protein sources, heat-treated samples were also introduced into the experimental diets. It was found that heat denaturation of the proteins led to results with somewhat increased biological value indices. The introduction of GM technology did not affect food intake or nutritional performance of the rats.
Authors:M. Arici, O. Daglioglu, T. Gumus, and F. Daglioglu
A total of 92 corn-based food products consisting of 53 low-processed and 39 processed samples were collected at random from retail markets and bazaars in various provinces of Turkey and analysed for total fumonisin levels. Twenty oneTwenty-one (40%) low-processed and nine (23%) processed samples were found to contain fumonisin. Total fumonisin contamination in the low-processed products ranged from 0.8 to 273 273 mg. mg kg-1, and in the processed products from 0.3 to 76.8 mg kg-. Considering all 92 samples, the highest frequency of detection and also the highest concentrations (in flour samples up to 273 mg kg-1) were detected in low-processed products. These results indicated the natural contamination of fumonisins corn-based low-processed and processed food products for human consumption in Turkey by fumonisins.
The free radical theory of aging posits that the accumulation of macromolecular damage induced by toxic reactive oxygen species plays a central role in the aging process. Therefore consumption of dietary antioxidants appears to be of great importance. Wheat germ have strong antioxidant properties. Aim of this study is investigate the effects of a wheat germ rich diet on oxidative mtDNA damage, mtDNA copy number and antioxidant enzyme activities in Drosophila. Current results suggested that dietary wheat germ enhances the activities of antioxidant enzymes in Drosophila. There was no statistically difference in mtDNA damage and mtDNA copy number results of “Wheat Germ” and “Refined White Flour” feed groups. mtDNA damage slightly increased with aging in both groups but these changes were no statistically different.