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The importance of selenium in the living world and in the scientific research
278-286Views:233Presently, selenium (Se) is one of the most investigated microelements. It has an important proven role in many vital processes. Directly or indirectly, selenium deficiency can play a role in the development of many diseases. On the other hand, the concentration range in which selenium is essential is narrow; there is a narrow gap between necessary and toxic content in dietary intake. In this context, selenium contamination poses a further health risk for people if they live near the industrial areas and mining activity.
In this paper, we comprehensively introduce the very important trace element selenium. We studied the base parameters, deposit, analytic and deficiencies, problem of contamination and also the solution of contamination problems of selenium. -
Effects of Site on Winter Wheat Quality 2002/2003
100-107Views:140The demand of modern societies for high food quality is evident. Thus, it is important for agriculture to produce row materials that are valuable for nutrition and have favourable characteristics for food processing. For this we need a knowledge about the factors which determine the quality of products. One of the main features of plant production is the “immobility”. This way the characteristics of the field influence the quality of the product, like example winter wheat, which is the main cereal in Hungary and Europe.
The Concordia Co. has charged the Central Laboratory of Debrecen University, Agricultural Centre with laboratory testing of the 2002/2003 winter wheat crop. The samples consist of thirteen winter wheat varieties from six different sites under the same cultivating conditions. Therefore, the important wheat quality factors were analysed solely against site conditions with the use of Győri’s “Z” index, which contains these parameters.
Soils were tested first. In this experiment excepting the negligible differences between the sites, there were no linear relations found between quality factors, productivity and soil features. The case is the same with the relation between precipitation, temperature and quality parameters. However, it must be noted that additional soil analyses are required to interpret the extreme results obtained from Karcag.
The calculated Győri’s Z-index shows relative stability concerning certain varieties, although considerable deviation can be found in varieties related to the sites. According to these results, it can bestated that winter wheat quality was not linearly influenced by soil and weather in the 2002/2003 vegetation period. As the same cultivation technology was used in the experiment, the index was determined by genetic features. It must be noted that these findings are relevant only to this experiment. -
Effects of Cropping Year and Artificial Fertilization on Alveographic Quality of GK Öthalom Winter Wheat Variety
126-133Views:114Qualification of winter wheat became more complex for Hungary, after the expansion of the EU. Use of Chopin alveograph is a general method in Western- and Southern Europe. This method is not traditional in Hungary, so determination of alveographic properties of Hungarian winter wheat varieties is very important. Artificial fertilization is one very important component of applied agricultural engineering, which effects winter wheat quality. The another factor is the weather or rather the cropping year, which effects winter wheat quality too. We examined both of them and the alveographic quality of GK Öthalom winter wheat variety between 1996 and 2003.
We found that cropping year has significant effect on the alveographic quality of GK Öthalom winter wheat variety on each treatment of artificial fertilization. We found no connection between quantities of precipitations of vegetation periods and the W values of GK Öthalom.
We found a strong connection in 1999 and 2003 as well as a very strong connection in 1996, 1997 and 2002, between the increase of fertilizer dose and W values of GK Öthalom. Treatments of artificial fertilization had a significant effect to W values of GK Öthalom in 2001 and 2002. The differences between the two methods are because of large standard deviation of the results. -
The composition of gluten proteins and their effect on the rheological properties of gluten
124-129Views:193Wheat is the major cereal component of bread in the world and is grown worldwide. Of the cereals only the bread wheats – and less the triticale – includes storage proteins that play an important role in the performance of gluten. Proteins of gluten complex may be present in two classes:
− low molecular weight (gliadin-) components, and
− high molecular weight (glutenin-) components.
Gliadins shown appreciable heterogenity and can be separated into 40-50 components with gel electrophoresis. The composition of gliadins is employable for the identification the wheat varieties and to investigate the varieties. In the decreasing electrophoretic mobility sequence may be distinguish α-, β-, γ- and ω-gliadins. A glutenin subunits may be include in two classes:
− high molecular weight glutenin subunits (HMW-GS),
− low molecular weight glutenin subunits (LMW-GS).
Wheat varieties can be identified by glutenin and their quality selection is also possible. The gliadin’s polypeptides encoding genes are located on the short arm of chromosomes 1A, 1B and 1D, 6A, 6B and 6D. Genetic coding for HMW subunits is located on the long arms of chromosomes 1A, 1B and 1D, the LMW-GS are also located on chromosomes 1A, 1B and 1D (Glu-3 loci) near the gliadin-coding loci.
Storage proteins affect the rheological properties of gluten by two factors:
1. The quality and quantity of the protein components of the gluten complex,
2. The interactions between the protein fractions. -
Application of the SDS-PAGE method for the characterisation of winter wheat flour quality
112-118Views:133The principle, development and importance of the SDS-PAGE method are presented in this article. The SDS-PAGE method has become one of the basic methods of molecular biological research, because it is widely applicable and its sensitivity is excellent in the separation of wheat storage proteins.
We have shown the application of this method with a concrete example. It was also tested whether, it was possible to obtain a better baking quality product from a large amount of poor quality less valuable wheat by fractioning the flour according to particle sizes after grinding. We studied the rheological properties of flours with different particle size fractions from the original flour. The baking quality of the original flour was B2. The 125-90 and 90-63 μm fractions have significantly better baking quality (B1) than the original flour. The protein contents of these flour fractions were also significantly higher than the protein content of the original flour. We had a question: what has influenced the baking quality: the protein content or other factors? We searched for an explanation on these results in the protein composition of the flour samples. We studied the distribution of glutenin-fractions by SDS-PAGE method and evaluated them. We found with correlation analysis that the amount of LMW-Glutenin D-group (52-60 kDa) is in a strong, negative correlation to the baking quality (r = – 0.855*). Therefore, the baking quality of flour samples was influenced by this glutenin fraction. -
Effect of weather conditions on the protein content and baking value of winter wheat flour
83-94Views:146We searched for connections between weather conditions (with its sub-parameters as precipitation and average temperature) and the yearly formation of two quality parameters (protein content and baking value) on three levels of mineral fertilization, based on the results of a variety comparison experiment on chernozem soil, to select those weather parameters and critical periods which have significant effects on the quality of winter wheat flour.
We established that the protein content of winter wheat flour can be increased with increasing levels of mineral fertilizers. Protein content is lower and has higher deviation during non-fertilized conditions in different cropping years than on higher fertilization levels. Thus, it seems proved again that quality (as protein content) is mainly formed by the crop year, but can be improved with adequate agricultural engineering (with mineral fertilization in the present case). The higher sum of precipitation in May, and the lower average temperature after flowering, have the highest increasing effect on the protein content of flour of the examined parameters. Based on the results of the examined period, the rainier and warmer term than average before flowering and lower – average amount of precipitation and colder circumstances are favourable for higher baking values. The analysis with data of decades, proves the importance of the first half of May and the middle of June as especially important periods for quality formation. An increasing nutrient supply has different effects on the varieties; mineral fertilization increased the baking value of GK Öthalom winter wheat variety in almost every case, but the second level of fertilization decreased it in half of the examined years. Additionally, mineral fertilization played a role in the stabilization of the quality of highlighted varieties. -
Comparison of the alveographic qualification and the baking quality of winter wheat
294-302Views:200On the basis of the operative French regulations, we qualified the alveographic qualification and the valorigraphic qualification respectively for each of the 10-14 winter wheat varieties grown each year between 2002-2005, and used in a field experiment at the Karcag Research Institute of the University of Debrecen. The field experiment at the Látókép Research Institute of the University of Debrecen allowed us to examine the alveographic and valorigraphic values of the samples of GK Öthalom and Fatima 2 winter wheat varieties taken from an 8 year period (1997-1999 and 2001-2005).
Throughout the experiments on samples from the Karcag Research Institute and Látókép Research Institute of the University of Debrecen, we tried to find whether the alveographic W value or the P/L value provides the safer method for the qualification of wheat samples, instead of the qualification commonly used in Hungary. We found that in terms of the samples from the Karcag Research Institute, the baking quality and the W value in each of the examined years, while in terms of the Látókép Research Institute, most of the years showed a close positive correlation, contrary to the close negative relationship between the baking quality and the P/L value. The correlation index varied depending on the year, the variety, and fertilizer doses, which require further examinations.