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The study of headspace sampling for the measurement of Volatile Organic Compounds byGC-MS
35-38Views:150Headspace sampling was studied for GC-MS measurements. A quick, direct method was developed for the measurement of petrol, gasoline and volatile organic solvent contamination of soil. According to our results this method is suitable for quick qualitative analysis of VOC contamination of soil, and helps to make decisions about further measurements. We concluded that an accurate quantitative measurement is not possible.
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Methods for detention of lipid rancidity
117-120Views:376There are various methods available for measurement of lipid oxidation in foods.Changes in chemical, physical, or organoleptic properties of fats and oils during oxidation may be monitored to assess the extent of lipid oxidation. However, there is no uniform and standard method for detecting all oxidative changes in all food systems. The available methods to monitor lipid oxidation in foods and biological systems may be divided into two groups. The first group measures primary oxidative changes and the second determines secondary changes that occur in each system.
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Application of AFLP-Method in Plant Sample Identification
207-213Views:82One possible method for the determination of DNA-polymorphism is the PCR-based AFLP (Amplified Fragment Length Polymorphism). This method had been succesfully introduced to the Department of Botany at University of Debrecen in 2000-2001 with the examination of hay saffron (Crocus sativus L.) and its allies. Hay saffron is grown as a spice for some thousand years producing the most expensive spice in the world. This plant is sterile, triploid reproduces only vegetatively with no fertile seeds. However its origin is unknown it exists only in cultivation and it is a mutated variety of another species or an artificial or natural hybrid. Usual methods for the systematic examination are restricted hence it seemed to be reasonable to apply molecular biological methods in its case. Results of this work include the introduction and many fold application of the method beside ensuring the consequences of science literature with determining the C. cartwrightianus to give the most similar genetical pattern to C. sativus.
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Response of sugar beet to different foliar fertilizers
127-136Views:142The yield and quality of the sugar beet are mainly determined by level crop production system; therefore the effects of foliar fertilization were studied. Our field trials were carried out in 2005 and 2006 in Hajdúböszörmény, at two experimental sites. In our trials the effects of Biomit Plussz, Fitohorm and Kelcare Cu (having high Cu content) as foliar fertilizers, as well as a fungicide with high sulphur content, Cosavet DF, were studied and
compared. Effects of treatments were studied in four replicates.
We took root samples at 4 week intervals, starting in August. The quality of root (sucrose, potassium, sodium and alfa-amino N content) was determined from filtrated beet broth, by an automatic beet laboratory system, called VENEMA. Leaf samples were taken three times in the growing season, element composition was measured by ICP-OES.
We found that the crop and the sugar yield were significantly influenced by the foliar treatments both of the two years. -
Changes of Quality of Winter Wheat During Maturing
105-112Views:129We analysed the flour of two winter wheat varieties to determine the effect of maturity state and grain position in the ear on the element composition of flour. Samples were taken from the 14th to the 42th day of anthesis. Ear samples were cut into three (basal, central and apical) parts, the trashed grains were milled, and the element compositions of the flours were determined.
We found that the grain position within the ear has an effect on flour element content. Flours of apical grains had lower nitrogen, phosphorus and sulphur contents than flours of central and basal grains. The nutrients can be divided into two parts, based on the formation of element content during maturation. Nitrogen, sulphur and copper contents changed continuously during maturity, while the P, K, Ca, Mg, Mn, Sr and Zn contents decreased until a specific value and became nearly constant in the second half of maturity. We found that – although the nitrogen concentration of flours changed continuously – the amount of nitrogen in the flours reached a constant value for the second half of maturity. -
Comparative analysis of physiologically important fatty acids
71-76Views:145Fatty acid composition of some vegetable oils, like wheat germ, walnut, peanut, hempseed, linseed, sunflower-seed, olive, rapeseed, grape seed or pumpkin seed, analysed at Food Science Institute of Debrecen University, are summarised here. The effect of heat treatments usually used in Hungarian cuisine was examined in this paper.The influence of different fatty acids on human health is also reviewed.
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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. -
Food safety of plant origin food
161-164Views:202Expectation regarding changes related to food production, transportation, distribution and marketing have changed considerably in several regions of the world over the past decades. It is especially true for highly industrialized countries where not only the food security is important but the food safety is essential too. The concentration of production – processing – distribution involves the danger on the one hand products of unsuitable quality from point of view of nutritional physiology and the other hand ones that may contain substances harmful to human health will become widespread among consumers. We investigated the heavy metal, pesticide remains and mycotoxin content of different plant products.
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Effect of the Cropping Year on the Quality of Winter Wheat
89-95Views:162We examined the formation of quality parameters of winter wheat in a small plot variety comparison experiment from four cropping years. Our aim was to estimate the year effect on several quality parameters of winter wheat.
We established in relation to the distribution of precipitation of the examined years that the years 1997 and 2000 were behind the thirty year average typical precipitation of this site both in the case of the whole vegetation period and the spring and summer. It was unfavourable for qualitative wheat production. 1998 and 1999 were good for cropping considering the amount and distribution of rainfall.
Examining the formation of quality parameters we found that the baking value was maximum in 1997, with a moderate amount of normal distributed rainfall for the examined varieties. The mid-late maturating varieties showed better baking value in drought years than in wet years. In the case of the wet gluten content, we established higher values after a rainier spring-summer period. There is a conspicuous difference between the falling number of extensive and intensive varieties and the year had significant effect on the formation of values. We established with correlation analysis that both the precipitation of vegetation period and the maturing rainfall had considerable effect on the value of falling number. Examining the effect of fertilization on the formation of wet gluten content as a quadratic equation, we found that precipitation may both increase and maximalize the value of this quality parameter. -
Examination of extensographical parameters of winter wheat (Triticum aestivum) flour
109-115Views:141In the trade of the European Union principally the analysis of alveographical and extensographical parameters mean the acceptance system.
In the present study we analysed the extensographical parameters of 10 winter wheat varieties breed by the Cereal Research Non Profit Company with Brabender extensigraph and we made a comparison, correlation among the results. The examinations with Brabender the following among: show the GK Kalász and the GK Élet varieties show high resistance of extension and the GK Petur variety produces high extensibility. The GK Garaboly has shown low extensibility and energy. The other parameters had different values in the examined three years. The measurings with SMS2 Texture Analyser show middle positive correlation between extensibility and subarea. There are weak correlation between at the significantial level in the 90, 135 resistence of extension by Brabender and by SMS2 Texture Analyser and in the 45 extensibility by Brabender and by SMS2 Texture Analyser of relaxed dough. There is no correlation among other parameters. -
Examination of wheat rheological characteristics by near-infrared spectroscopy
99-104Views:165Near-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.
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Changes in the Quality of Winter Wheat Varieties in a Comparative Experiment
179-183Views:119The hungarian seed grain supply offers more and more varieties from the field crops for public cultivation in every year. The number of the admitted varieties by state doubled from 1996 to 2001. The question is what changes can the varieties newly inproved show in the quality parameters.
32 varieties admitted in different years was examined on quality parameters as wet gluten content, valorigraphic value and falling number from period 1996-2001. We established that the newer varieties surpassed the traditional varieties of the variety-comparativing experiment in accordion to they wet gluten content. In connection with formation of valorigraphical value we saw that the new varieties got place in the varieties admitted for public cultivation in quality based examining. The varieties showed different reaction of fertilizer on the formation of these two parameters. In connection with the formation of the value of falling number the examined varieties suited for the requirements of quality crop production in the experimental years excepted some of them. -
The examination of alveographical parameters of winter wheat varieties
87-91Views:157Nowadays, many methods have been worked up in the interests of objective expression of winter wheat rheological quality. These define wide spectrum in view of their complexity and apparatus claim. The needs for the methods are definitely increasing in Hungary, too. It is very important to get acquainted with the alveographical quality and qualification and also their using in wide range.
In our research we examined the alveographical parameters of 12 winter wheat varieties in Szeged (in Hungary) on the basis of the results in three years (2005-2007).
We established with correlation analysis that there is no statistical relation between the alveaographical W and G values. The other alveographical parameters have significant correlation. -
The composition of gluten proteins and their effect on the rheological properties of gluten
124-129Views:194Wheat 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. -
New possibilities to determine wheat quality parameters by near-infrared spectroscopy
65-69Views:178Analyses 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.