The intensity of neutron beams is measured by neutron beam monitor detector at research reactors, in order to allow normalization of neutron scattering data. A two dimensional position sensitive neutron beam monitor has been developed, able to measure the distribution of beam intensity in its cross-section. The neutron adsorption efficiency of these monitor detectors are low enough to minimize the intensity loss, but high enough to provide low statistical error. Since the number of detected events is not too high, the dead time is not crucial for these detectors. A novel readout method has been developed that slightly increases the dead time but eventuates a robust, simple and flexible system. This new method relies on the serial connection of the delay-lines, minimizing the number of analogue signals. Two or three analogue signal outputs are enough to reconstruct the two-dimensional intensity matrix. Combining this new method with a comprehensive acquisition on the primary signals, the quality parameters of the detectors are also improved. Design and measurement results at the Budapest Research Reactor are presented.
Authors:Ildikó Buocz, Nikoletta Rozgonyi-Boissinot and Ákos Török
The paper summarizes the results of direct shear strength tests carried out on Opalinus Claystone deriving from a fault zone, at the site of Mont Terri (North-Western Switzerland). In Mont Terri an Underground Rock Mechanical Laboratory is conducting studies aimed at specifying the rock mechanical parameters of the rock surrounding, which is at the same time the potential host rock of a highly active radioactive waste disposal facility. The samples for the tests were derived from blocks and cores collected from the main fault zone, during the excavation of a tunnel, named: Full scale Emplacement demonstration experiment Gallery (FE Gallery). Direct shear strength tests were carried out on 50x50 mm samples undergoing a 1 MPa constant normal load, where the natural shear plane was parallel to the direction of the shear. The orientation of the bedding planes in the samples was recorded and the maximal shear strength and residual shear stress were determined. The maximal shear strength values obtained from the tests fell in the interval 0.34-0.78 MPa, while the residual values fell between 0.31 and 0.72 MPa. The effect on the shear strength of different angles defined by the bedding and the shear plane of the samples was also examined. The bedding of the samples enclosed different angles with the shear plane, ranging from 0 to 49 degrees.
The research is done at the simulation laboratory of the energy design research group of the University of Pécs. Aim of the research is to design a multifunctional shading structure, which is warmed up by solar radiation and then starts an evaporative cooling process. Via this evaporative process the shading structure itself and also the climate facade is cooled down. The experimental climate façade of the Szentágothai Research Center will be used for the purpose of this research. Integrating the shading structure to the climate façade further investigations and simulations will be available.
Authors:A. Lugasi, G. Kádár, K. Alb, E. Schreiber Molnár and É. Martos
Caffeine content of 377 food samples obtained from the Hungarian market was measured by a validated HPLC technique. The highest caffeine levels were observed in different instant coffees (3954±2355 mg/100 g) and ground coffee beans (1634±389 mg/100 g). Significant amount of caffeine could be detected in energy drinks (119 mg in 100 ml at the highest end). The caffeine content of different coffee drinks varied between 40 and 203 mg/100 ml. Significant amount of caffeine could be measured in special instant coffees called 2in1 and 3in1 (120 mg per serving at the highest end), cacao powders (125 mg in 100 g), in chocolates (on average, 16.1 mg and 52.5 mg in 100 g milk and dark chocolate, respectively), breakfast cereals (between 5.7 and 15.8 mg per 100 g), and ice creams (1.7–24.8 mg in 100 g).
Authors:O. Csernus, J. Beczner, F. Sebők, M. Tóth and Cs. Dobolyi
The surface microbial contamination is of great interest in case of fruit because of the threat of postharvest spoilage. Apple is a valuable product from growing, commercial, as well as from nutritional points of view. Apple diseases during the growing season can be satisfactorily controlled by different plant protection technologies, but postharvest decay of apples caused by the so called storage moulds cannot be completely avoided. Cold storage — alone, or in combination with other methods — is the main technology used to successfully prolong the shelf life of apples. The origin of the moulds causing the decay of apples during storage is not well understood. In this work the surface mycobiota of apple fruit grown in Soroksár, in the orchard of the Corvinus University of Budapest was investigated.
Laetiporus sulphureus (chicken of the woods) is a wood decaying mushroom with positive medicinal and biological effects. The aim of this study was to determine its chemical composition including the main organic components (protein, fat, fibre, and ash contents, different protein fractions, the free amino acid level, soluble oligo- and polysaccharides, phenolics), the in vitro digestibility, the free radical scavenging activity, and twenty mineral elements.Our data demonstrate the characteristic in general valuable chemical composition of the mushroom Laetiporus sulphureus. Protein content in fruiting bodies is not too high (10.6% d.m.), but the biological value (in vitro digestibility, rate of protein fractions, free amino acid content, etc.) is good (including fat and energy levels). Occurrence of “bioactive” components (phenolics, soluble oligo- and polysaccharides) and the measured free radical scavenging activity are similar to these parameters in Pleurotus (oyster) species. Potassium and phosphorus contents are remarkable (28 940 mg kg−1 d.m. and 4890 mg kg−1 d.m., respectively); levels of some poisonous microelements (As, Cd, Cr) are very low or undetectable. Chicken of the woods (Laetiporus sulphureus) is not only a suitable species for human consumption, but can be a new cultivable mushroom of valuable bioactive substances.
Six coloured and six non-coloured waxy rice varieties were analyzed by determining amylose, fat, and protein content, pasting, and thermal properties. Significant differences in protein content as well as pasting properties between coloured and non-coloured waxy rice were identified. It was demonstrated that protein may have a main influence on pasting and thermal properties of waxy rice. In addition, the optimal linear relationship between protein and pasting or thermal properties was found by combining RVA and DSC data using Principal component analysis (PCA). Typical indicators, which can classify coloured and non-coloured waxy rice, could be identified by Hierarchical cluster analysis (HCA). In pasting properties, trough and consistency viscosity were typical indicators; in thermal properties, enthalpy and stop temperature were typical indicators.
Authors:E. Fogarassy, E. Bekassy-Molnar, Cs. Balla and Gy. Vatai
In this study, pressed apricot (Prunus armeniaca L.) juice was concentrated using complex membrane technology with different module combinations: UF-RO-OD, UF-RO-MD, UF-NF-OD and UF-NF-MD. In case of the best combination a cross-flow polyethylene ultrafiltration membrane (UF) was applied for clarification, after which preconcentration was done using reverse osmosis (RO) with a polyamide membrane, and the final concentration was completed by osmotic distillation (OD) using a polypropylene module. The UF-RO-OD procedure resulted in a final concentrate with a 65-70 °Brix dry solid content and an excellent quality juice with high polyphenol content and high antioxidant capacity.Nanofiltration (NF) and membrane distillation (MD) were not proper economic solutions.The influence of certain operation parameters was examined experimentally. Temperatures of UF and RO were: 25, 30, and 35 °C, and of OD 25 °C. Recycle flow rates were: UF: 1, 1.5, and 2 m3 h−1; RO: 200, 400, and 600 l h−1; OD: 20, 30 and 40 l h−1. The flow rates in the module were expressed by the Reynolds number, as well. Based on preliminary experiments, the transmembrane pressures of UF and RO filtration were 4 bar and 50 bar, respectively. Each experimental run was performed three times. The following optimal operation parameters provided the lowest total cost: UF: 35 °C, 2 m3 h−1, 4 bar; RO: 35 °C, 600 l h−1, 50 bar; OD: 20, 30 and 40 l h−1; temperature 25 °C.In addition, experiments were performed for apricot juice concentration by evaporation, which technique is widely applied in the industry using vacuum and low temperature.For description the UF filtration, a dynamic model and regression by SPSS 14.0 statistics software were applied.
Shelf-life of plant oils is determined by oxidative stability. The consumers use their own criterion to assess oil’s quality. The occurrence of perceptible changes in oxidized food provides information that the product is no longer safe and should not be accepted. The present study was aimed to determine the shelf-life of rapeseed and sunflower oils in terms of consumer acceptance. The results of sensory consumer acceptability tests followed by survival analysis were integrated with conventional chemical marker of oils’ quality and shelf-life (peroxide value).The important finding is that consumers sometimes do not recognize the advanced oxidative processes in food. This may increase the safety risk because of the harmful effect of oxidative processes on human health. Consumers differentiated quality of oils with similar state of oxidation: the rapeseed oil with peroxide value on the level 5 meq O2 kg−1 was rejected by three quarters of consumers, sunflower — by only 3%. It proves that the consumer perception of oxidative changes is specific to the product and does not coincide with the accepted chemical criterion of shelf-life.
Authors:T. Somogyi, I. Holló, J. Csapó, I. Anton and G. Holló
The aim of this study was to determine the effect of genotype and type of muscle on the mineral content of beef. Altogether 62 young bulls from Angus, Charolais, Holstein, Hungarian Simmental, Hungarian Grey, and Charolais×Hungarian Grey were used. The calcium content varied between 26–46 mg kg−1, in longissimus muscle of Hungarian Simmental it was significantly higher than for other genotypes except for Angus. Psoas major of Holstein had the highest phosphorus content, it significantly differed from the longissimus of Angus. Longissimus muscle of Angus was the poorest for magnesium, and the richest was the psoas major of Holstein and Hungarian Grey. Charolais had higher level of potassium in psoas major than Angus and Charolais×Hungarian Grey. Sodium content of semitendinosus in Charolais×Hungarian Grey was lower than in Holstein. Present data showed that levels were detected in the longissimus of Angus and semitendinosus of Holstein. Concerning zinc, a higher level was found in longissimus, especially for Holstein. The results confirmed that beef mineral content depends on genotype, and is related to muscle type, too.
Authors:A. Mikulajová, Z. Kohajdová, K. Németh and E. Hybenová
Whole cereal flours (buckwheat, barley, and oat) and wheat bran were used to substitute 20% of white bakery wheat flour to prepare round rolls. Round roll quality was evaluated by determining total phenolic and total flavonoid contents, antioxidative capacity, the content of lipid hydroperoxides (primary oxidation products), and sensory profiling. Moreover, the stability of the phenolic compounds and antioxidant behaviour throughout processing was studied. Technological processing does not cause any significant loss of phenolics (less than 5%). A significant increase in antioxidants and phenolics of the flour mixtures and final products were observed compared to those of white wheat round rolls (as control). Buckwheat and barley round roll crumbs contained the highest total phenolic and total flavonoid contents, and were the most effective in enhancing antioxidant activity, which increased 15-fold and 8-fold, respectively, when compared to the control roll. The tested cereals effectively retarded formation of lipid hydroperoxides (from over 50% to control), which are undesirable from both a nutrition and storage/shelf life perspective. The results of sensory analyses showed that such bakery products are accepted by consumers with the exception of the product made with oat flour, where a reduction in the oat content would be preferable.
Authors:M. Kadivec, M. Kopjar, D. Žnidarčič and T. Požrl
In this study ascorbic acid and phenolic compounds contents of eggplant flesh and eggplant peel were determined. Among the investigated eggplant cultivars generally eggplant peel had higher ascorbic acid and phenolic compounds contents than eggplant flesh. Ascorbic acid content in eggplant flesh ranged from 33.62 to 92.75 mg kg−1 and in eggplant peel from 12.45 to 111.01 mg kg−1. Phenolic compounds content ranged from 11.77 to 22.18 g kg−1 in eggplant flesh and from 13.46 to 29.42 g kg−1 in eggplant peel. Eggplant peel is usually treated as waste, i.e. byproduct, omitting its potentially beneficial characteristics. Due to higher ascorbic acid and phenolic compounds contents, further investigations should be directed on possible use of eggplant peel as natural ingredient for functional products formulation.
Even if plants can contain high levels of nitrate and nitrite, milk and dairy products are not described as sources of these anions. The purpose of this paper was to measure the concentrations of nitrate and nitrite in forage, cow blood, and milk.The results show that the nitrate ratio of milk to plasma is very low, suggesting that milk contamination with nitrate is unlikely to occur. This finding also proves the lack of an active transport mechanism to transfer nitrate from blood to milk. The nitrite anion almost disappears from milk through an enzymatic conversion; usually levels of μg l−1 were measured.
Authors:G. Gulyás, L. Czeglédi, B. Béri, S. Harangi, E. Csősz, Z. Szabó, T. Janáky and A. Jávor
The aim of this study was to investigate the differences in the proteome patterns of musculus longissimus dorsi between Charolais bulls slaughtered at 500 kg and 700 kg live weight using two-dimensional difference in gel electrophoresis (2D-DIGE) and liquid chromatography-mass spectrometry (LC-MS). Three hundred fifty protein spots were visualised on gels of which 10 showed different expression levels (P<0.05) between groups. After mass spectrometric analysis of spots, beta-enolase (ENO3) in five different spots, alpha-enolase (ENO1), triosephosphate isomerase (TPI1) in two different spots, alpha-actin (ACTA1), and heat shock protein beta-1 (HSPB1) were identified. ENO3, ENO1, TPI1, and ACTA1 had higher expression levels in bulls of 700 kg live weight group. ENO3, ENO1, and TPI1 are involved in energy metabolism, while ACTA1 is a structure protein in skeletal muscle. Up-regulation of heat shock protein beta-1 (HSPB1), which protein is reported to have correlation with tenderness, was observed in 500 kg weight group. Our result demonstrates that proteomic tools are useful in identifying markers associated with muscle development.
Authors:V. Singh, N. Guizani, I. Al-Zakwani, Q. Al-Shamsi, A. Al-Alawi and M.S. Rahman
Eight descriptive sensory textural attributes of whole date fruit were evaluated by twenty trained panel members and correlated with sixteen physicochemical properties. All sensory parameters, except gumminess, significantly correlated (Ps<0.05) with pectin, crude fibre, and moisture content. In addition, sensory hardness, cohesiveness, elasticity, and resilience correlated significantly with length of whole fruit (P<0.05), sensory adhesiveness with glucose content (P<0.05), sensory chewiness with mass of whole fruit (P<0.05), and sensory gumminess with fructose, glucose, and total sugar content (P<0.10). Sweetness, however, correlated only with moisture content (P<0.05). CA and the biplot (i.e. including all products, their sensory texture and physicochemical attributes) generated through PCA recognized three groups of dates as hard-chewy, soft-(medium-chewy), and soft-(non-adhesive).
The purpose of the study was to assess the sodium and potassium intake among Hungarian children and adolescents. The study was undertaken to estimate daily sodium and potassium intake by measuring 24-h urinary electrolyte excretion rate in 200 Hungarian children (age 1–18 years). Daily sodium and potassium intake positively correlated with age, body mass index, and systolic blood pressure. As a result of the parallel trend and time course of urinary sodium and potassium excretion the sodium to potassium ratio, the important risk factor for essential hypertension remained practically unchanged with age. We did not find a significant difference in this ratio between hypertensive and normotensive, or obese and non-obese children. Sodium and potassium intake expressed per kilogram body weight decreased steadily with age, but there was no significant difference between boys and girls. When adjustment was made for age and body mass index, using multivariate regression analysis, the systolic blood pressure proved to be independent of urinary sodium excretion and daily potassium intake. Compared with Dietary Reference Intake values, the present study demonstrates that, on average, Hungarian children and adolescents have a diet rich in sodium, and poor in potassium, although during the last 20 years a favourable trend can be detected.
Basil has traditionally been used for a long time in medicine and gastronomy. Essential oil is the most important active substance of the drug, which influences the aroma and the effect of the plant. Although the compositions of essential oils vary in different basil cultivars, the main components are oxygenated monoterpenes and phenylpropane derivates. The high chemical variation is most likely caused by interspecific hybridization. Various factors, like genetic background, ontogenesis, morphogenesis, abiotic factors, essential oil extraction method, drying, and storage, are responsible for the variant essential oil composition.
Authors:V. Szente, O. Szigeti, Zs. Polereczki, Á. Varga and Z. Szakály
In Hungary, organic food market has both demand and supply oriented aspects: several times not necessary products are distributed, while the selection and volume of certain products are not satisfactory. Thus, our aim was to develop a coordinated benchmark strategy to increase the trade of organic products. To get more details on the Hungarian organic milk market, we conducted professional deep interviews and simultaneously applied the “mystery shopping” method. Nowadays, the market of organic milk and dairy products is slowly increasing in Hungary, however, there is no available statistical data. In the selection there are mostly Hungarian originated products, but some yoghurt, milk, and butter assortments are imported. Partial responsibility belongs to small sale shops’ habit of risk-avoidance. Without a proper selection of products, stores are unable to satisfy consumers’ needs; thus they focus on pushing certain products to increase demand. According to our results, ‘low price category’, ‘local/regional product’, and ‘prestige product’ strategies with attached in-store marketing elements are able to reverse the effects of an unfavourable marketing process.
Authors:B. Khakimov, G. Gürdeniz and S.B. Engelsen
There is an ever-increasing trend in advanced food analysis and foodomics to use more and more sophisticated analytical platforms that generate large and complex data structures, which in turn require more and more sophisticated data analysis tools for converting data into information. The choice of multivariate chemometric methods is primarily determined by the design of the study, type of the data, and the conclusions sought. In order to validate multivariate models, scientists are required to have basic chemometric knowledge and to be familiar with the variance structure of the investigated data. This review outlines some of the key aspects of applying common chemometric methods used within foodomics and provides selected examples of current applications. The review aims to provide simple insight into various multivariate methods and to illustrate pros and cons of unsupervised and supervised methods. The main analytical platforms used in foodomics are briefly discussed from the application point of view and the utilization of the generated data is illustrated. In addition, advanced data pre-processing tools, prior to multivariate analysis, are explained and relevant tools are demonstrated.
Authors:T. Buday, Gy. Szabó, I. Fazekas, M. Paládi, Sz. Szabó, G. Szabó and A. Kerényi
Heating with the use of ambient energy by heat pumps is a very effective way to reduce CO2 emission. However, efficiency, economic and environmental advantages depend on the type of the heat pump and the temperature of the source, the latter usually changes during the heating season. The aim of the paper is to give the annual pattern of the COP and emission as a function of the typical source temperature pattern, moreover yearly summarized energetic and emission values are also added in the case of air source, water source and ground source heat pump systems, compared to some conventional heating mode.
Authors:A. Abou El-Ela, A. Kinawy, R. El-Sehiemy and M. Mouwafi
This paper proposes an approach for optimal placement of phasor measurement units (PMUs) for complete observability at normal and emergency conditions such as any single line outage or any single PMU loss using ant colony optimization (ACO) algorithm. The objective function is to find the optimal locations of PMUs and the minimum number of PMU channels by optimizing the logic decision of control variables, under the observability constraint. The ACO algorithm is applied to the standard IEEE 14-bus, 30-bus and New England 39-bus systems. In addition, an application of the proposed algorithm to a real power system of the west Delta network (WDN) as a part of the Unified Egyptian Network (UEN) is presented. The results obtained are compared with those obtained using other techniques. Simulation results show that the proposed ACO algorithm is more accurate and efficient for obtaining the optimal placement of PMUs with minimum number of PMU channels, especially with increasing the system size.
Composites made from E-glass/epoxy or aramid/epoxy are frequently used in aircraft and aerospace industries. These materials are prone to suffer from the presence of delamination, which can reduce severely the performance of aircrafts and even threaten their safety. Since electric conductivity of these composites is rather small, they can propagate electromagnetic waves. Detection of delamination damage can then be monitored by using an electromagnetic penetrating radar scanner, which consists of emitting waves having the form of short time pulses that are centered on a given work frequency. While propagating, these waves undergo partial reflection when running into an obstacle or a material discontinuity. Habitually, the radar is moved at constant speed along a straight path and the reflected signal is processed as a radargram that gives the reflected energy as function of the two-way time and the antenna position.In this work, modeling of electromagnetic wave propagation in composites made from E-glass/epoxy was performed analytically. The electromagnetic wave reflection from a delamination defect was analyzed as function of key intervening factors which include the defect extent and depth, as well as the work frequency. Various simulations were performed and the obtained results have enabled to correlate the reflection pattern image features to the actual delamination defect characteristics which can provide quantification of delamination.
Authors:A. Matkó, E. Szűcs, T. Takács and S. Kovács
Today, companies have to face new challanges because of the globalization, new technologies, globalization of markets and increasing competition. In this accelerated world, it is essential that the companies adapt to the market, which is only available through the necessary information. The importance of market research is undoubted. In our study we would like to prove that in case of a beginner company — in this case a confectionery — it is important to perform a market research like for a company in any other segment. To perform it, the qualitative market research methods were used. Our questionnaire examines several aspects in order to provide an indication of the company’s founding.
Authors:S. Teidj, A. Khamlichi, A. Driouach and A. Limam
Detection of cracks in mechanical components as early as possible enables monitoring structural health and scheduling efficiently the maintenance tasks such as replacing the critical parts just in time. Vibration analysis based techniques for crack detection have been largely considered in the framework of beam-like structures. This methodology relies essentially on the observed changes of beam frequencies and mode shapes induced by the presence of damage. In the present work, using an explicit analytical model assessing the effect of a crack on beam strain energy, the beam first resonance frequencies as they depend on a single crack defect characteristics were evaluated. The crack equations were obtained by means of fracture mechanics approach. Variations of the first beam frequencies and modes shapes were then related explicitly to the location and depth of the crack. Measuring the beam frequency changes and monitoring their variations can be used to perform identification of the crack defect parameters by solution of an inverse problem.
The paper presents an intelligent building (IB) development strategy emphasizing the locally available non-polluting renewable energy resources utilization. Considering the immense complexity of the topic, the implementation strategy of the main energy-flow processes is unfolded, using the net zero-energy building concept (NZEB). Noticeably, in the first research steps the mathematical background of the considered NZEB strategy has been developed and presented. Then careful LabView software-based simulations prove that the adopted strategy is feasible for implementation. The result of the above mentioned research efforts is a set of powerful and versatile software toolkits well suitable to model and simulate complex heating, ventilation and air-conditioning processes and to perform energy balance performance evaluations. Besides the elaborated mathematical models, concrete software implementation examples and measurement data also is provided in the paper. Finally, the proposed original models offer a feasible solution for future developments and research in NZEB applications modelling and simulation purposes.
Impacts of macrosynoptic weather patterns on the development of the thermal excess in suburban areas of Debrecen are examined in this paper. Temperature datasets have been recorded at two heights by three automatic weather stations mounted in Debrecen (east Hungary) and a small settlement in its vicinity. An additional automatic weather station is used as a reference station outside Debrecen. Urban heat island (UHI) intensities have been calculated from the raw datasets. Impacts of synoptic conditions have been analyzed on the base of Péczely’s macrosynoptic types. It has been found that anticyclone types are more favorable from the aspect of UHI development, while cyclone types, especially the passage of warm fronts can effectively hinder the formation of strong heat islands in Debrecen.
Authors:T. Mankovits, I. Budai, G. Balogh, A. Gábora, I. Kozma, T. Varga, S. Manó and I. Kocsis
The development of an efficient procedure for 3d modeling and finite element simulation of metal foams is one of the greatest challenges for engineer researchers nowadays. Creating 3d CAD model is alone a demanding engineering task due to its extremely complex geometry, and the proper finite element analysis process is still in the center of the research. The increasingly widespread application of the metal foams, e.g. in vehicle and medical industry, requires this knowledge in the design phase. A closed-cell metal foam is studied using different analyzing methods where the aim is to collect information about the composition and geometry (structure) that is satisfactory for the later research. Using statistical methods microscopic, X-ray and surface analyzing studies on the specimens produced according to the concerning standard are evaluated. The main goal of this part of the project is to obtain structural information and to determine the homogeneity or the in-homogeneity property of the metal foam specimens taken from different locations.
The present paper of a series deals with the experimental characterisation of tensile splitting strength and compressive behaviour of different structural concrete containing different volume of steel fibre reinforcement (0 V%, 0.5 V%, 1.0 V%, 75 kg/m3, 150 kg/m3) and different configuration of steel fibres (crimped, hooked-end). Tensile splitting tests were carried out on standard cylinder (∅ = 150 mm, l = 300 mm) specimens (so-called Brazilian test) considering random fibre orientation. Since the fibre orientation may significantly affect the tensile behaviour test series were also performed on cross-section (100 mm × 100 mm) of steel fibre reinforced concrete beams (100 mm × 100 mm × 240 mm) sawn out of steel fibre reinforced slab elements. Taken as a whole behaviour of steel fibre reinforced concrete was examined in tension taking into consideration different experimental parameters such as fibre content, type of fibres, fibre configuration, fibre orientation, size of specimens (size effect) and concrete mixture.
The present paper of a series deals with the experimental characterisation of flexural toughness properties of structural concrete containing different volume of hooked-end steel fibre reinforcement (75 kg/m3, 150 kg/m3). Third-point flexural tests were carried out on steel fibre reinforced concrete beams having a cross-section of 80 mm × 85 mm with the span of 765 mm, hence the shear span to depth ratio was 3. Beams were sawn out of steel fibre reinforced slab elements (see Part I) in order to take into consideration the introduced privilege fibre orientation (I and II) and the position of the beam (Ba-a, Ba-b, Ba-c) before sawing (see Part I). Flexural toughness properties were determined considering different standard specifications, namely the method of the ASTM (American Standards for Testing Materials), the process of the JSCE (Japan Society of Civil Engineering), and the final proposal of Banthia and Trottier for the post cracking strength. Consequently, behaviour of steel fibre reinforced concrete was examined in bending taking into consideration different experimental parameters such as fibre content, concrete mix proportions, fibre orientation, positions of test specimens in the formwork, while experimental constants were the size of specimens, the type of fibre used and the test set-up and test arrangement.
This paper integrates a Real Power Differential Scheme (RPDS) for power transformer protection. The suggested RPDS for power transformer computes the active power loci during normal operation, switching, normal, and internal, involves turn to turn, and external faults at varied load angles. The proposed RPDS concept is based on monitoring and comparing the transformers primary and secondary active and reactive powers. The dynamic response of the proposed RPDS is tested 300 MVA, 220/66 kV, Y/Δ transformer. Furthermore, the suggested scheme is simulated with the use of Matlab/Simulink then tested for various fault and switching conditions. Moreover, the RPDS is checked for inter turn fault conditions at primary and secondary sides. The evaluation of the suggested scheme confirms the superiority of the proposed scheme to distinguish internal and external faults as well as magnetizing inrush currents with good selectivity, high speed, sensitivity, stability limits and high accuracy response of the power differential scheme. Finally, the suggested scheme is able to detect correctly the turn to turn faults for wide range of fault resistances but fails at very low values.
Authors:B. Szabó-Nótin, R. Juhász, J. Barta and M. Stéger-Máté
The aim of the present study was to investigate whether apple pomace powder produced by a simple drying method is suitable for replacing pectin in bakery jam products. Rheological properties of bakery jams were tested by oscillatory tests using amplitude sweep method. Apple pomace addition decreased gel strength and stability of bakery jams, while 12-month storage increased the gel strength of samples. Based on our results, dried apple pomace powder seems to be suitable to replace pectin up to 40% without changing rheological properties of bakery jams.
Authors:J. Soós, E. Várvölgyi, L. Dénes, Z. Kovács, J. Felföldi and I. Magyar
In this work, the application of an electronic tongue (ET) based on a specific ion-selective sensor array for discrimination of different white wine types is presented. The electronic tongue equipped with specific sensor array containing seven IFSET sensors was used to analyze wine samples. The obtained ET responses were evaluated using different pattern recognition methods. Principal component analysis (PCA) provides the possibility to identify some initial patterns. Linear discriminant analysis (LDA) was used to build models to separate white wine samples based on wine regions and grape cultivars. The results showed that every group was distinguished from each other with no misclassification error. Furthermore, the sequence of the wine sample groups was similar to the increasing total acidity content. Partial least square (PLS) regression was used to build models for the prediction of the main chemical compositions of the wine samples based on the electronic tongue results. The closest correlation (R2=0.93) was found in case of ‘total acidity’, and the prediction error (RMSEP) was 6.9%. The pH of the wine samples was predicted with good correlation (R2=0.89) but higher prediction error (RMSEP=10.71%) from the electronic tongue results. The ET combining these statistical methods can be applied to determine the origin and variety of the wine samples in easy and quick way.
An immunoreaction-based method was investigated for the detection of aflatoxin M1 (AFM1), which is the hydroxylated metabolite of aflatoxin B1 (AFB1). This mycotoxin may be found in milk and milk products obtained from livestock that have ingested contaminated feed. Quantitative analysis of AFM1 was carried out using indirect (competitive) immunoassay method, which can be used for low weight molecules. The real-time measurement was done with Optical Waveguide Lightmode Spectroscopy (OWLS) technique. After the optimization of the chemical and biochemical parameters (determination of the optimal concentration of the immobilized AFM1-protein conjugate, determination of the AFM1 antibody content of the samples, etc.) real samples were also examined. Three kinds of milk sample preparation methods (filtration, centrifugation, size exclusion centrifugation) and two dilution rates (100 and 200 fold) were compared. The presented competitive immunoassay method showed the best results when 100 fold diluted filtered or centrifuged milk samples were examined. The dynamic measuring ranges for AFM1 were 0.001–0.1 ng ml−1 and 0.0005–0.01 ng ml−1, respectively.
Authors:D. Székely, L. Szalóki-Dorkó, M. Stéger-Máté, B. Szabó-Nótin, J. Ivanics and J. Monspart-Sényi
The beetroot is typically on the table in winter in form of pickles or juice, but for its nutritional values it would deserve more common consumption. Its curative effect in great part is due to the several vitamins, minerals, and compounds with antioxidant activity. But the division of biological active compounds is very different in the parts of the root. Based on our results, we could compare the differences between the morphology and some inner contents (soluble solid content, colour, betacyanin, betaxanthin, and polyphenol contents, antioxidant activity, and some flavonoids) of two beetroot cultivars. The results of the morphological investigations showed that the ‘Cylindre’ cultivar had more favourable crop parameters than the ‘Alto F1’ cultivar. In the ‘Cylindre’ cultivar the polyphenol content and the antioxidant capacity were significantly higher than in the ‘Alto F1’ cultivar. By determination of the betanin contents of the investigated beetroots, our results showed both betacyanin and betaxanthin contents were higher in the ‘Cylindre’ cultivar. The chlorogenic acid, gallic acid, the cumaric acid have been identified based on the peaks of HPLC in the studied beetroot cultivars.
Authors:V. Parrag, J. Felföldi, L. Baranyai, A. Geösel and F. Firtha
From the nineteen-nineties, cobweb disease caused serious losses for the mushroom sector in Europe, in the USA, and in Australia (Fletcher & Gaze, 2008), so it is one of the most notable fungal infections of cultivated white button mushroom (Agaricus bisporus). The aim of this study was to identify cobweb disease (Cladobortyum dendroides) caused cap spotting and brownish rot on the mushroom sporocarp, and to find a proper discrimination method in the case of this infection.Fruiting body samples were divided into 4 groups, a control one and three others treated with different chemicals that are tested against fungal infections. The groups were subdivided into 2 portions and the first was infected with cobweb disease. Images of the caps were recorded and their hyperspectral images were acquired in the wavelength range of 900–1700 nm.On the hyperspectral images infected and healthy areas were selected, on these average spectra differences were found around the known water peaks (1200 and 1450 nm). The spatial distribution of the water content can be used for the detection of the spoilage, because the infected areas showed different reflection values at these water absorption peaks.Support Vector Machine method was applied successfully to discriminate between the infected and control groups and Monte Carlo cross-validation was carried out.
Authors:G. Hitka, T. Zsom, L. Nguyen and Cs. Balla
1-Methylcyclopropene (1-MCP) is the active component of the SmartFresh Quality System. By the application of the 1-MCP compound, quality of the harvested pears can be preserved longer during the normal cold storage. In our work, the effectiveness of the SmartFresh Quality System was investigated on ‘Bosc Kobak’ pears (Pyruscommunis L.) harvested at different times. The rheological changes and storage losses were measured. The effectiveness of 1-MCP depends on many variables, but our results show that the optimal harvest date and the condition of the harvested fruit are the most influential factors.
High hydrostatic pressure (HHP) technology, as a promising alternative of thermal-treatment and chemical preservatives, can be used to produce minimally processed foods. It has the advantage of affecting only non-covalent bonds of macromolecules in foods, and thus preserves nutritional components, taste, and flavour exceptionally well. However, HHP also influences enzymatic reactions of food. Although some of these changes are often beneficial, monitoring the potential effects of high pressure treatments — especially in the field of product and technology development — is essential. The aim of this study was to point out some parameters of high hydrostatic pressure technique (pressure, temperature, build-up time, holding time, number of cycles) that can substantially impact the sensory properties of treated products.
Authors:Á. Belák, B. Héher, Z. Füstös, M. Kovács and A. Maráz
Endophytic microorganisms living inside plant tissues might have numerous positive effects on the host plants. Endophytes can promote the growth and yield of the plant, help to remove contaminants from the tissues, and can suppress growth of pathogens; however, some enteric human pathogenic bacteria have also been isolated as endophytes. The aims of our study were the characterisation and identification of endophytic coliform bacteria isolated from different cultivars of sweet pepper (Capsicum annuum var. grossum) using a selective (VRBL) agar medium, and determination of antagonistic interactions between these endophytes and Listeria monocytogenes. The bacterial isolates showed heterogeneity based on their phenotypic and genotypic properties. Results of identification by molecular biological methods also confirmed the presence of different genera/species. When the antagonistic effect of the isolated endophytic bacteria was tested it was found that one isolate — identified as Pseudomonas putida — showed significant inhibition on the growth of Listeria monocytogenes.
Authors:M. Molnár, L. Hornyák, R. Nagy, E. Márki and Gy. Vatai
Our experiments were based on a model solution containing five of the main pineapple aroma components. Both sweeping-gas pervaporation and vacuum-pervaporation methods were carried out. Measurements were performed at different temperatures and feed flow rates. The purposes of this study were to examine applicability of the two pervaporation methods in reference to the pineapple aroma recovery, the effects of the operating parameters on the process, and modelling the pervaporation process by resistance-in-series model. Higher enrichment could be reached with vacuum-pervaporation than the sweeping-gas method. The separation process is determined by the diffusion of compounds in the membrane, thus the resistance in the boundary layer at liquid side is negligible. Based on performed experiments, the pervaporation process can be applied in beverage industry for aroma recovery.
Authors:Sz. Szélpál, Zs. Kohány, E. Fogarassy, I. Galambos, A. Koris, J. Csanádi, Gy. Vatai and C. Hodúr
The largest quantities of by-products of dairy processing originates from the cheese making. Whey proteins are used for animal feeding and human nutrition as well, for example in dry soups, infant formulas, and supplements. The fat components of the whey might impair its use. The aim of our experiments was to investigate the separation of the lipid fraction of whey. The microfiltration is said to be a gentle and energy efficient method for this task. During the measurements 0.2 μm microfiltration membranes were used and the membrane separation was enhanced by vibration, inserting static mixer and air sparging. The de-fatting efficiency, the retention of the whey components, the flux values, and the resistances in different combinations were compared in this paper.
Authors:V. Szűcs, L. Guerrero, A. Claret, M. Tarcea, E. Szabó and D. Bánáti
Important differences have been reported in several countries about the level of concern in connection with food additives. In order to better understand the consumer preferences related to foodstuffs containing food additives, five hypotheses were tested with the help of a choice-based conjoint analysis. The study was performed in three European countries (Hungary, Romania, and Spain) having different risk perceptions concerning food additives. Two “model foodstuffs” were involved in the analysis: pre-packed sliced cheese (natural image) and chips (artificial image). For the creation of the conjoint cards, three attributes were selected: “preservatives” (natural/artificial), “packaging gases” (contains/does not contain) and “price” (average based on market data/+10%/+20%). Results were collected via Internet simultaneously and a total of 500 valid questionnaires were received in case of pre-packed cheese and 468 regarding chips. In the analysed countries “preservatives” had an outstanding importance — mainly in Hungary and Romania —, while “packaging gases” got lower importance during the shopping intention. “Natural preservatives” very positively contributed to the choosing of both pre-packed sliced cheese and chips. High level of willingness to pay was not observed, as well as the “price” was less important factor than the additives. Comparison of the data from three countries showed notable differences, which can determine the direction of the product planning and development.
Authors:P. Havas, Sz. Kun, G. Styevkó, V. Slačanac, J. Hardi and J. Rezessy-Szabó
Consumers are becoming more interested in healthy nutrition. To meet consumer requirements, the possibility of the fruit and vegetable juice fermentation by bifidobacteria was investigated. Sour cherry, orange, carrot, and tomato juice was fermented with five Bifidobacterium strains (from human origin and starter culture). The tested strains have grown well in orange, carrot, and tomato juices. The B. longum Bb-46 strain demonstrated the best growth activities. It was found that ratio of the produced acetic and lactic acids are dependent on the Bifidobacterium strain rather than on the fermentation medium. The most intensive inhibition was observed against the Campylobacter jejuni strain. In course of the fermentation the antioxidant capacities slightly decreased, except when the orange juice was fermented with B. lactis Bb-12 and B. longum A4.8. The obtained results may contribute to the design of a novel functional food product.
The objective of this study was to investigate the influence of irrigation on the composition and content of phenolic compounds and carotenoids in different tomato cultivars using HPLC/DAD-UV technique and reverse-phase (RP) chromatographic columns for analysis. Among phenols, the quercetin derivatives and hydroxycinnamic acids and their derivatives were the major compounds, while lycopene was the dominant carotenoid in the extract of tomato. It was found that the response of tomatos to shortage of water is affected by genetic factors and seasonal environmental variations. In general, 100% irrigation yielded tomatoes with the lowest level of carotenoids and polyphenols. In 2012, when the temperature and number of sunny hours were at record levels, the non-irrigated plants of cultivar Strombolino yielded tomatoes with significantly higher levels of carotenoids and phenols than that of the other cultivars.
Authors:O. Fehér, Sz. Podruzsik, Zs. Bogóné and P. Boros
As a result of the fast innovation activity, the so called “many to many” communication channel has become one of the most important tools for the Hungarian food industry. The number of Internet users in Hungary was 6.5 million in 2011 that represents 65.4 percent of the total population. The Internet based social media provides a strong and active platform between food producers and consumers. The online platform gives up-to-date and precise information about food companies and food products to the consumers. The information flow is two-directional as food companies receive a precise overview on consumers, their habits and latent needs by using innovative market research methods. The aim of this paper is to present an example and to evaluate the customers’ socio-demographic profile and their preferences of a dominant food company and its product. We used data mining techniques to get more precise and the latest information about Hungarian food consumers. This survey supports more efficient marketing communication and strategies for the innovation of the food products.
Authors:R. Tömösközi-Farkas, M. Berki, M. Nagy-Gasztonyi, I. Wolf and Zs. Polgár
We have investigated the Total Glycoalcaloid (TGA), nitrite, and nitrate contents of some Hungarian and foreign potato cultivars in relation to the effect of different combination of fertilisers and green manure, late blight management strategies (none, programmed, or prediction based spraying), and irrigation regime for three years. The Hungarian cultivars have exotic potato species like S. acaule, S. demissum, S. stoloniferum, S. vernei, or S. tub. ssp. andigenum in their genetic background as sources of resistance genes. No effect of fertilisers or irrigation was found on the level of glycoalkaloids and nitrate contents, which were influenced mostly by the genotype and season. In conclusion, the absolute amount and the presence of different antinutritive components of potato tubers were influenced by the technology, genotype, and season in a complex manner. These results in general prove that ware potato production utilising intensive commercial agrotechnical practices and common cultivars is safe regarding the nitrate and TGA content of tubers.
Yeasts of the Yarrowia clade frequently occur in meat and milk products. In many cases they cause spoilage due to their strong lipolytic and proteolytic activity, and their ability to produce brown pigments. Using conventional methods, some of these yeasts can be misidentified as Yarrowia lipolytica, but using molecular biological methods it can be stated that they are members of a complex group including several different species. The aims of this study were to find a proper method to collect Yarrowia strains from raw meat, and to assign them to groups based on their physiological and molecular characteristics, followed by sequence-based identification of the selected members of each group to determine the composition of the species. This study revealed three novel Yarrowia species. From 62 samples of different raw meats 291 yeast strains were isolated, from which 118 strains proved to be members of the Yarrowia group. They could be assigned to seven species. Four of them are described species, three of them are novel ones.
The role of fats in food technology is mainly to develop the desired consistency. The simplest way to reach this goal is the blending of different fats. The aim of our work was to study the solidification and melting properties of blends of coconut oil and anhydrous milk fat. Pure fats and their 25–75%, 50–50%, and 75–25% blends were investigated. Melting profile and isotherm crystallization were measured by pNMR. Non-isotherm melting and solidification were detected by differential scanning calorimetry (DSC). Possible applications of the blends were established. Results show that AMF and coconut oil has limited miscibility, which is dependent on the temperature. Below 22 °C AMF is the softening component, above 22 °C the effect is inverse. Coconut oil accelerates solidification of AMF, however, basic crystal forms of AMF remained.
Authors:I. Szedljak, K. Szántai-Kőhegyi, M. Tóth and B. Bernhardt
Millet has attracted a great deal of interest due to its valuable agricultural, nutritional, and functional properties. In this study the aim was the investigation of millet usability in dry pasta products. Chemical, enzymological, and sensory parameters were measured and monitored in Triticum aestivum, Triticum durum, and millet containing pasta products during a 12-month-long storage period. According to our results, during the storage, millet had a strong effect on different parameters: because of increased acid value, the shelf life was reduced, and millet significantly influenced the pH value and the water soluble polyphenol content. The highest scores were measured in T. durum and T. durum-millet pasta samples in the sensory test, while the T. aestivum-millet mixture pasta got the lowest scores. Also in our experiment we tested how the drying temperature modifies polyphenol oxidase enzyme (PPO) activity right after drying and during storage. The samples containing millet flour had higher PPO activity in all cases after drying, while pasta made with T. durum had the lowest PPO activity. Our results showed that drying temperature has a significant impact on PPO activity.
The food industry is in the crossfire of increasing pressure of competition, consumer demands, and growing importance of ecological sustainability considerations. Life cycle analysis is one of the most important methods for evaluation of environmental effects of food industrial technologies and packaging systems. During the last decades there have been an intense work to collect pieces of information on different environmental aspects of food packaging systems all over the world, but there is a considerable gap between the amount of knowledge and its practical application in decision making on the level of enterprises as well as in the process of determination of environmental protection fee. Application of modern, freely available software frameworks for life cycle analysis offers a favourable possibility for integration of environmental information into managerial and governmental decision making processes. Based on case studies, the article demonstrates the possibilities of utilisation of cumulative environmental burden indicators as well as expert decision-support systems for optimisation of product-portfolio, based on environmental considerations.
Authors:T. Zsom, V. Zsom-Muha, D. Dénes, G. Hitka, L. Nguyen and J. Felföldi
Postharvest quality changes of two pear and five sweet pepper varieties during cold storage (2±1 °C and 10±1 °C, respectively) and shelf-life (22±2 °C and 20±1 °C, respectively) by non-destructive optical methods (laser backscattering imaging, chlorophyll fluorescence analysis, surface colour measurement) and texture analysis methods (acoustic impulse-response technique, impact method) were determined and monitored. The rate of the change of ‘Conference’ pears’ Fv/Fm chlorophyll fluorescence parameter was lower than for ‘Bosc kobak’, referring to the cultivar characteristic and photosynthetically active chlorophyll content related maturity and colour change. Acoustic and impact stiffness decreased during shelf-life, referring clearly to temperature related textural change. Taking into account the seven different measuring wavelengths (650–1064 nm), laser scattering parameters showed significant and cultivar dependent changes versus time during cold storage and shelf-life. The used non-destructive methods were found to be suitable for objective sweet pepper quality determination. Cold storage combined shelf-life resulted in a relatively longer shelf-life, with a lower intensity and rate of quality decrease in time, based upon mass loss, stiffness, surface colour, and chlorophyll fluorescence changes. ‘Gigant’, ‘Carma’, and ‘Kárpia’ cultivars were found to be favourable, but ‘Kais’ and ‘Kun’ hot pepper samples were really sensitive to quality degradation.
In a period of economic crisis, there is a constantly increasing need to have a general picture on the place and role of different branches in fabrics of modern, open national economies. Based on Leontief’s input-output model, using the unified, structural database of OECD, the article analyses the economic role of the food industry in national economies of OECD member states as well as in economic structure of some important emerging markets by approach of network analysis. Applying this unique combination of a comprehensive database and network analysis methods, it is proven that the centrality of the food industry, determined on the basis of these indicators, is much higher than the average of other sectors of the national economies. This fact can be explained by the specific “bridge” role of the food industry between the different sectors of national economy. Results have proven the importance of the food industry and highlight the necessity of revision of governmental resource-allocation principles for R+D and industrial policy in member-states of the European Union.
An appropriate rheological model can be used in production of good quality gum candy required by consumers. For this purpose Creep-Recovery Test (CRT) curves were recorded with a Stable Micro System TA.XT-2 precision texture analyser with 75 mm diameter cylinder probe on gum candies purchased from the local market. The deformation speed was 0.2 mm s−1, the creeping- and recovering time was 60 s, while the loading force was set to 1 N, 2 N, 5 N, 7 N, and 10 N. The two-element Kelvin-Voigt-model, a three-element model, and the four-element Burgers-model were fitted on the recorded creep data, and then the parameters of the models were evaluated. The best fitting from the used models was given by the Burgers model.
Authors:G. Rácz, M. Alam, Ch. Arekatte, K. Albert, N. Papp, É. Stefanovits-Bányai, P. Russo, M. DiMatteo and Gy. Vatai
Different osmotic agents (OA), such as potassium acetate (CH3COOK), potassium carbonate (K2CO3) and ammonium nitrate (NH4NO3), have been examined as alternatives to the traditionally used calcium chloride (CaCl2) for osmotic distillation concentrating of clarified and pre-concentrated sour cherry (Prunus cerasus L.) juice. Comparison of the process performances based on the permeate fluxes has been carried out. Regarding the permeate flux results, simplified estimation of the overall mass transfer coefficient of the most effective osmotic agent and the reference (CaCl2) solution has been also performed. Furthermore, analytical methods such as total antioxidant activity (TAA) and total polyphenolic content (TPC) using spectrophotometric assays have been also carried out to evaluate the effect of the osmotic distillation on the valuable compounds content of concentrated sour cherry juice. CH3COOK was found to be the most effective, resulted more than 25% higher permeate flux during the sour cherry juice concentration. K2CO3 and NH4NO3 were less effective. The simplified mass transfer estimation showed that the CH3COOK is more effective only at near saturated concentrations compared to the CaCl2. Regarding the TAA and TPC contents, a significant loss was found in case of all OAs during the concentration procedures.
Authors:L. Darnay, A. Dankovics, B. Molnár, L. Friedrich, Gy. Kenesei and Cs. Balla
Several scientific papers suggest that microbial transglutaminase (mTG) is capable of reducing the salt content of cured and/or heat-treated meat products (ham, frankfurters, meat ball). These scientific results are not widely known in Hungary, and as a result of this, only little experience was gathered in our meat industry. According to this lack of knowledge, our aim was to lower the curing salt to a still microbiological safe level using mTG by frankfurters, one of the most well-known heat treated meat products in Hungary. The observed technofunctional properties suggest to use mTG enzyme preparation at 0.5% concentration. This enzyme dosage can reduce the average 1.8% salt content to 1.6% and it also may contribute to extended shelf life of popular frankfurters. Our sensorial analysis revealed that the panellists have not found a loss in quality between 1.4% and 1.6% salt.
Authors:K. Albert, A. Koris, I. Gáspár, G. Rácz and Gy. Vatai
Membrane emulsification (ME) is a relatively new technique for the highly controlled production of particulates, which helps to obtain a narrower distribution compared to other emulsification techniques such as homogenizers or ultrasound. Benefits of membrane emulsification for food applications include the low shear properties and the uniform size distribution. In this process, the dispersed phase (oil) is pressed through the pores of a microporous membrane directly into the continuous phase (water) flowing tangentially to the membrane surface. The purpose of the emulsification experimentations was to find and model operating conditions of the operation. In laboratory experiments from conventional, commercial grade sunflower oil (dispersed phase) and from distilled water (solid phase), emulsions were prepared. The ceramic tube membrane with nominal pore size of 1.4 μm was used in the experiments (ZrO2). In order to increase the shear-stress near the membrane wall (influence the characteristics of the flow regime of the continuous phase), a kind of self-fabricated helical-shaped-ribbon reducer was installed inside the tube membrane.
Authors:E. Várvölgyi, T. Werum, L. Dénes, J. Soós, G. Szabó, J. Felföldi, G. Esper and Z. Kovács
Time consuming and expensive methods have been applied for detection of coffee adulteration based on the literature. In the present work, an optical method (vision system) and the application of an electronic tongue is proposed to reveal the addition of barley in different proportion to coffee in ground and brewed forms. In a range of 1 to 80% (w/w) Robusta coffee was blended with roasted barley. Principal Component Analysis (PCA) accomplished on vision system image data showed a good discrimination of the adulterated samples. The results of Polar Qualification System (PQS) data reduction method revealed even small differences in the right barley content order by point method approach. With Partial Least Squares (PLS) regression the amount of barley in Robusta was predicted with high R2 (0.996) and relatively low RMSEP (∼2%) values in case of vision system data processing. Considering electronic tongue measurements, PCA results showed a good discrimination of samples with higher barley concentration. Misclassification was found in the low concentrated area by Lienar Discriminant Analgsis (LDA). To obtain an accurate model for barley content prediction in coffee, the most sensitive sensor signals were used to apply PLS regression successfully (R2=0.97, RMSEP=3.99% (w/w)).