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Methods for detention of lipid rancidity
117-120Views:990There 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:352One 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:444The 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:559We 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:493Fatty 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:737Presently, 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:480Expectation 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:536We 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:468In 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:431Near-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:542The 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:421Nowadays, 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:524Wheat 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:516Analyses 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.
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Quality management and traceability in crop production
273-277Views:558Today, food safety and quality is an everyday issue. Scandals in the food industry drew attention to the role and responsibility of food producers in the food chain. The European Union has set up a new integrated approach towards food safety, to which Hungary as an EU member and export-oriented country has also joined. The new “from farm to fork” principle states that food and feed production cannot be handled separately, as only feed produced from good quality raw materials can ensure safe food products. Another important issue is the traceability of products, allowing for the localization and recall of the defected item. In Hungary, there have been different documentation systems for tracking and tracing products, such as the land register in crop production, animal register in the livestock sector and hygiene registers in the food industry. In order to meet EU requirements, there is a growing number of initiatives to include primary production in the scope of food safety standards. The study introduces and compares the various management systems used in crop production.
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The relationship between gluten proteins and baking quality
117-122Views:760Wheat, one of the most important cereals, is grown on the largest area in Hungary. During hydration of storage proteins of wheat – gliadin and glutenin – the gluten complex is evolved. The gliadin is responsible for the extensibility of gluten complex as well as the glutenin for the strength of gluten. The structure, composition and rheological properties of gluten proteins influence significantly the baking quality. The gliadin/glutenin ratio and the quality and structure of glutenin fraction play the most important role in evolving gluten complex. Changes in the steps of breadmaking technology also have effect on the quality of product. Several tests proved that the higher glutenin content increases the strength of dough while the higher gliadin content increases the extensibility of dough and decreases maximum resistance to extension. The monomer gliadins play a great part in plasticity of glutenin polymer. The quality of glutenin fraction significantly influences the evolving gluten complex, because of the spiral structure of glutenin which deforms under stress conditions, then the β-spiral structure resumes their original conformation by releasing from stress.
The final quality of product evolves as a result of complex characteristics of wheat proteins, so detailed knowledge on the roles of different protein compounds is the base of the quality oriented product development. -
Element Content of Herbaceous Plants in the Floodplain Meadows
55-58Views:494Animals require well-balanced nutrition. The elemental content of the vegetation of meadows is influenced by as many factors such as heat, rainfall, irrigation, soil type and nutrients, meadow types, species, aspects of the vegetation period and cultivation.
Natural meadows used extensively are common sights on river floodplains. Since chemicals are banned and the species number is high, measuring the elemental composition of plants on these meadows is beneficial. Cenological survey and element content measurements were held on the rich flora of four natural meadows in the year 2001.
Weeds, in a wider sense, are plants not directly involved in growing, although their nutritional values make them important costituents of feed. Meadows are enriched by their relatively high microelement content.
On the sampling sites, the ratio deviated from the ideal 2/3 parts monocotyledon and 1/3 part dicotyledon, but this did not mean a Mn deficiency as it would have been assumed. -
Studying of quality parameters of Hungarian and Greek honey samples
147-153Views:889Honey has been a valuable food for mankind since ancient times. It was the only sweetener until the start of industrial sugar mass production. Honey plays an important role in our nutrition and its positive effects on health are well-known. The quality of Hungarian honey is perfect, so it is very important to safeguard and monitor its quality continuously and to build up a good traceability and quality assurance system. For such a system, it is necessary to study the nutritional properties and the origin of different honey samples. In our study, we study Hungarian and Greek honey.
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Comparison of macroelement and microelement contents of conventionally and organically grown crops
87-92Views:552Nowedays one of the most important issues to discuss is the healthy nutrition: feeding our bodies with high quality nutrients, which is free of chemical residues. The demand for healthy and nutritious food is increasing worldwide, that results in the growing popularity of consumption of organic food. Several studies dealing with the nutrient content of traditional and organic food have been published lately, since it became clear that eating food contaminated with chemical residues damage to health, food and the environment. Therefore it would be desirable to find out if organic food is really superior to conventional one. In our study we analyzed the dry matter, ash, macroelement and trace element content of organically and conventionally grown crops (carrot root, potato tuber and parsnip). Our results provide further information to consumers about the nutritional value of organic and conventional crops.
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Investigation of the Quality of Winter Wheat in a Sulphur Fertilisation Experiment, 2001/2002
153-156Views:451We have started a small parcell and a factorial S fertilization experiment with winter wheat in the 2001/2002 cropping year to examine its effect on yield and quality. The scene of experiment was the Latokep Experimental Station of the DE ATC (calcareous chernozeem) in case of small parcell examination and the Agricultural Company of Felsőzsolca (brown forest soil) in case od factorial examination.
The protein and gluten content of the grain was investigated with PerCon Inframatic 9001 NIR Analyser, then we have measured these parameters with PerCon 8620 infra appliance. After the milling we measured the following parameters: glutenindex, farinographic parameters (farinographic index, water absorption capacity, dough development time, stability, softening, extension) and valorigraphic index.
Based on the results there’s no justified relation between the fertilization and the protein and gluten content. The valorigraphic index of the samples taken from Felsőzsolca factory characteristically increased as a result of the S-fertilization. In the small-parcell experiment the values of the water absorption capacity, the dough development time and the softening parameters from the valorigrphic parameters depended significantly from the mineral treatments. Signifikant quality improvement wasn’t experieced.
There was sampling in all of critical phenophase (…). The green plant samples were examined on element content with ICP-OES. These measurements are currently in progress. -
Influence of Foliar Treatments on the yield and quality of Sugar Beet
119-123Views:480The yield and quality of the sugar beet are mainly determined by the plant production system, thus we studied the effect of mineral fertilization. Our field trials were carried out in 2005 in Hajdúböszörmény, at two sites. We studied the effect of sulphur (Cosavet DF), copper (Kelcare Cu) and two foliar nutrients with high active agents. Treatments were replicated four times.
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.
We found that the crop and the sugar yield were significantly influenced by the foliar treatments -
Study of traditional folk foods from the point of view of nutrition in Hajdú-Bihar County
47-51Views:467Healthy nutrition is one of the major topics of our days. The occurrence of the so called “civilization diseases” is increasing continuously as a result of the changes in our nutritional habits and life-style. It was thought that folk nutrition at the beginning of the 19. Century had several beneficial effects on health. For this reason it was decided to study the food and nutritional habits of the population of Hajdu-Bihar County around the 1930s on the
basis of literary sources to see how well they do match with modern requirements of healthy nutrition. -
Research on rheological characteristics of winter wheat varieties
266-272Views:700The gluten examination test is dominant in Hungary, comparing it to the qualification system of other countries. The determination of alveographic parameters is a basic criterion of winter wheat specifications in some western and southern European countries.
In the Hungarian and foreign winter wheat qualification systems, in the standards, there is no limit for extensographical parameters. Customers dictate the limits and make their claims as to the specifications.
We analyzed the alveographic and extensographical parameters of 19 winter wheat varieties grown by the Cereal Research Non-Profit Company in Hungary, and we made a comparison between the results in the challenges of the European Union expectations.
Examining the information of alveographic and extensographical values, we found that the experimental varieties provide high base to flour types suitable for baking bread and baker’s ware. The GK Élet, GK Petur, GK Memento, GK Csillag, GK Kapos and GK Marcel varieties can meet the market of paste flour needs, too.
In the variety series, the GK Kalász represents the highest values and the GK Garaboly shows the lowest parameters regarding the alveographic W and the resistance to extension.
On the basis of relation, we can establish that we can estimate the following little known and used quality indexes: the extensographical resistance to extension with extensographical energy and the alveographic W value, the extensographical energy with the alveographic W value and the alveographic P and L values with the other alveographic parameters. -
Quality analysis of the near-infrared spectra of wheat samples
97-100Views:350The near infrared spectroscopy is widely used in the different industries as a rapid, non-invasive analitical tool. It is suitable for identification, qualification and quantitative analysis as well. As this technique is indirect, to make accurate calibration equations we need a proper sample population. Before the quantitaive analysis, developing calibiration modells we have to collect and examine the spectra. In our study we examined wheat samples with known origins to find if there is any effect of the growing area on the NIR spectra.
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The Effect of Grazing Intensities on Magnesium Contents
8-13Views:805Research was carried out on two areas of grassland in Hortobágy National Park, Hungary. Two herds of Hungarian Grey Cattle were kept in free range grazing and the effects of grazing pressure on the magnesium content of soil and ryegrass (Lolium perenne L) were determined.
Changes of plant available and total soil magnesium content under different grazing intensities did not show any evident tendency on the investigated grasslands. Different amounts of cattle faeces, urine and trampling had no effect on the magnesium concentration of ryegrass. We conclude that the magnesium content of ryegrass on both grassland sites as moderate grazing and overgrazing matches the requirements of cattle. Symptoms of magnesium deficiency of cattle will likely not appear.