10,782 research outputs found

    Chromosomal control of wheat endosperm proteins. A critical review.

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    Progress made in the chromosomal location of structural genes for wheat endosperm proteins, and in the study of the regulation and quantitative expression of these genes, by using aneuploids and by related techniques, is critically evaluated. Recommendations for future work are proposed

    Binding of Oxovanadium(IV) Complexes to Blood Serum Albumins

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    In this work the binding of VIVO2+ and VIVO-complexes to serum albumins {human serum albumin (HSA), bovine serum albumin (BSA) and porcine serum albumin (PSA)} are studied using circular dichroism (CD), electron paramagnetic resonance (EPR) and visible absorption spectroscopy. The results confirm previous findings that VIVO2+ occupies at least two types of binding sites on albumin: ‘the strong vanadium binding site’ (designated by VBS1) and ‘the weak vanadium binding sites’ (designated by VBS2). VBS1 binds 1 mol equivalent of VIVO2+. On the other hand VBS2 correspond to binding of several mol equivalents of VIVO, and studies done with PSA in the presence of excess ZnII ions indicate that VSB2 corresponds to two distinct types of sites. The hyperfine coupling constant Az for VIVO2+ binding at VBS2 on HSA and BSA are all very similar (~168 × 10-4 cm-1) but differ slightly on PSA (~166 × 10-4 cm-1) due to differences in the binding sets. When (VIVO)-HSA systems are titrated with maltol ternary species of (maltol)m(VIVO)mHSA and (maltol)2m(VIVO)mHSA stoichiometry form which are clearly distinguishable from the binary (VIVO)-HSA system by the type and intensity of the CD spectra recorded. Changes are also observable in the intensity of the X-band EPR spectra, but not much in the hyperfine coupling constants Az, which are all in the range 166-167 × 10-4 cm-1. The results further demonstrate that the presence of maltol may enhance the binding of VIVO to albumin

    Sulfur and baking-quality of breadmaking wheat

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    It is well known in biological science that all factors applied to living organisms (light, water, warmth, fertilizers etc.) show an optimum, when their input is increased. Healthy organisms and sus-tainable systems are, on the long run, only achieved when care is taken not to destroy this equilibrium of factors producing an optimum. With regard to the baking quality of wheat breeders and cereal scientists obviously failed to achieve this aim by breeding their cultivars on the background of ample S depositions in the ecosystems. They (involuntarily) selected plants showing definite characteristics of S deficiency (higher proportions of HMW-glutenin, stronger gluten and dough) even under conditions of ample S supply. I suppose they also selected plants with a high warmth susceptibility as this also delivers firm protein structure. When this environ-mental pollution was stopped and S supplies returned to natural conditions, even with a non S craving plant like wheat, problems arose with the gluten structure as doughs turned out so strong that the baking volume decreased. So one may ask, particularly with regard to S, if the plant constitutions of our modern wheat cultivars are still harmonious and in balance. And as a consequence ot that also the nutritional quality of these cultivars is rather questionable

    Human serum albumin crystals and method of preparation

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    Human serum albumin (HSA) crystals are provided in the form of tetragonal plates having the space groups P42(sub 1)2, the crystals being grown to sizes in excess of 0.5 mm in two dimensions and a thickness of 0.1 mm. Growth of the crystals is carried out by a hanging drop method wherein a precipitant solution containing polyethylene glycol (PEG) and a phosphate buffer is mixed with an HSA solution, and a droplet of mixed solution is suspended over a well of precipitant solution. Crystals grow to the desired size in 3 to 7 days. Concentration of reagents, pH and other parameters are controlled within prescribed limits. The resulting crystals exhibit a size and quality such as to allow performance of x ray diffraction studies and enable the conduct of drug binding studies as well as genetic engineering studies

    Technological quality of organic wheat in Europe

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    The demand for high quality organic bread wheat is increasing. The quality level of organic wheat harvested in EU is mainly dependant on variety, environmental conditions and agronomic practices. In some countries, protein content and composition, influencing technological value, are equivalent to those produced under conventional practices. Beside agronomical techniques, technological processes can help to maintain a good quality. Pre-treatments before milling such as debranning were found to be efficient in reducing DON contamination. The project highlighted the necessity to redefine the methods to assess the quality of organic wheat

    A Component Methodology to Assess The Impact of Protein Imports on the U.S. Dairy Industry

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    This paper provides an assessment of the protein content of U.S. trade in dairy products and their potential impact on U.S. milk prices. The protein in imports of MPC, Casein & Albumins accounted for 5-6 percent of protein in total U.S. consumption during the period 1997-2002.Livestock Production/Industries,

    The influence of long-term inputs of catch crops and cereal straw on yield, protein composition and technological quality of a spring and a winter wheat

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    Under conditions of restricted nitrogen (N) input such as in organic farming systems, crop N uptake must rely on N mineralised from applied animal manure, crop residues and native soil organic matter. Scarcity of N may impede the production of quality grain for bread production, and input and retention of N in soil are therefore important parameters for soil fertility. Toretain N in the crop-soilsystem, catch crops may be grown in breaks between main crops where they provide a significant sink for N mineralised in late summer and autumn (Thomsen, 2005). In corporation of straw may likewise retain mineralised N by microbial immobilisation (Christensen, 1986) and will also directly add to the N mineralisation potential when the N supplied in the straw accumulates (Thomsen & Christensen, 2004). Under northern European conditions, winter wheat may generally be of lower quality than spring wheat, but winter wheat has a higher yield potential. When the N uptake is mainly based on N mineralised from either applied or indigenous soil organic matter, however, this may even out the quality difference between winter and spring wheat as the longer growing season of winter wheat may boost its N utilisation. Growing conditions are highly important for protein quantity whereas main lygenetic factors influence protein composition (Amesetal., 1999; Luoetal., 2000). Wheat grain proteins have been classified as albumins, globulins, gliadins and glutenins on the basis of their solubility (Osborne, 1907). Reverse-phase (RP) high performance liquid chromatography (HPLC) allows the quantitative determination of these different flour protein groups together with single proteins (α5-, α1,2-, α-, γc-type gliadins, x- and γ-type high (HMW) and low (LMW) molecular weights subunits of glutenin) (Wieser & Seilmeier, 1998). The proteins can also be divided into polymers (glutenins) or monomers (gliadins, albumins, globulins) based on their aggregating properties. The polymeric proteins are critical for governing wheat flour processing properties, and their quantity and size distribution reliably measured by size-exclusion (SE) HPLC techniques have been shown to be important indicators of baking quality (Dachkevitch & Autran, 1989; Bateyetal., 1991). The aim of this study was to examine whether wheat yield and baking quality determined by chromatographic techniques together with rheological and chemical quality measurements could be improved by combining agronomic strategies consisting of wheat cultivars and long-term organic matter inputs. The variables tested were (A) a winter wheat and a spring wheat cultivar, (B) three catch crop strategies and (C) four straw incorporation rates

    Aplinkos įtaka duoninių (Triticum aestivum L.) ir kietųjų (Triticum durum Desf.) kviečių albuminų kiekiui

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    Albumins or water soluble proteins (wsp) in wheat are important as nutrients containing high content of essential amino acids such as lysine, tryptophan, methionine, and also asparagine, glutamine, arginine, and proline in comparison to storage proteins-glutenins and gliadins. Fifteen bread wheat (Triticum aestivum L.) and 15 durum wheat (Triticum durum Desf.) genotypes were evaluated across six different environments for two years to determine the content of albumins in grains. The purpose of this research was to determine the variability of the albumins content of the tested bread wheat and durum wheat genotypes, effects of environment, genotype and their interaction (GEI) on the trait of interest, heritability in a broad sense, stability, and also to interpret GEI by climatic factors modelling. The statistical procedure included analysis of variance, sites regression and factorial regression. The mean content of albumins was 20.23 g kg-1 in bread wheat and 23.12 g kg-1 in durum wheat. Environment followed by GEI was the most important in determining albumins content. The heritability in a broad sense was low, i.e. 31.3% for bread wheat and only 2.4% for durum wheat. GEI for the albumins content was explained with the efficacy of 94.7% and 94.2% of sum of squares, for bread wheat and durum wheat, respectively, by the following models: mean temperature in May, winter moisture reserves, minimum temperature in April and March for bread wheat; and precipitation sum in April, sunshine hours sum in March, maximum temperature in May, and winter moisture reserves for durum wheat. The simultaneous selection for high albumins content and good stability proved to be possible for bread wheat genotypes, but less for durum wheat genotypes due to unsatisfactory stability
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