Authors:S. Cevik, G. Ozkan, M. Kiralan and A. Bayrak
The aim of this study was to determine the changes in some physicochemical properties of olives (fruit weight, water content and oil content) and olive oils (total chlorophyll, carotenoid, pheophytin a, peroxide value and free acidity), and in the chemical properties (fatty acids, tocopherols, phenolics, oxidation stability and volatile profiles) of oils during ripening.Ripening indices (RI) of olive samples were 1.93 (unripe), 4.28 (ripe) and 5.89 (overripe). Most of the mentioned features changed with ripening. During ripening there was a sharp decrease in total chlorophyll, carotenoid and pheophytin a contents. An increase in oleic and linoleic acids and a decrease in palmitic acid were found in the fatty acid composition. Olive oils showed strong relations among oxidation stability, tocopherol content, total phenols content, and antiradical actvity of phenol extracts and these parameters decreased with maturation. Nevertheless, higher amounts of trans-2-hexenal were found in the oil from ripe olives than from unripe and overripe olives. On the other hand, the highest concentration of hexanal was found in the oil from overripe olives.In general, significant differences were observed in fruit weight, pigments, free acidity, fatty acid, tocopherol, and total phenolics contents, radical scavenger activity, oxidation stability, phenolic profile and volatile profile between the olive oils from the Gemlik cultivar at different stages of maturation.
Bambara bean protein concentrate was acylated and partially hydrolysed with pancreatin in order to improve its functional properties. Increasing acetylation and succinylation (from 0.0 to 1.0 g anhydride/g concentrate) modified lysine at similar rate. Acylation markedly improved protein solubility and water solubility index at neutral pH, which reached to 92 and 94%, respectively. Acetylation showed greater effect on emulsifying activity, which was maximum at 0.5 g anhydride/g concentrate, and emulsifying stability was higher at 0.25 g anhydride/g concentrate. A significant increase in foam capacity was recorded at 0.5 g succinic anhydride/g concentrate, and foam stability decreased detrimentally following acylation. Fat absorption capacity was not improved by acylation. At pH 3.5, protein solubility of acylated concentrate was low (<14%). Hydrolysis of protein concentrate with pancreatin resulted in significant increase in protein solubility at neutral pH. At isoelectric pH, solubility of protein hydrolysates increased with the increasing degree of hydrolysis.
Authors:J. Belovai, R. Romvári, H. Fébel, A. Szabó and D. Bánáti
The n-3 fatty acids advantageously affect human health. Thus, partial substitution of pig backfat with soybean- or flaxseed oils in “Párizsi” (lyoner), with the aim to increase its n-3 fatty acid (FA) content, resulted improved FA profile (n-6/n-3 ratio). Relatively high (9% flaxseed oil) substitution decreased this ratio to the optimum (∼4). This modified FA profile was preserved during 32 storage days. Oil addition influenced fresh surface colour: lightness (L*) increased, redness (a*) decreased in parallel with the increasing oil addition, while only soybean oil increased yellowness (b*). Storage altered the colour slightly. The texture was not systematically altered by oil substitution, while during storage in a vapour permeable casing hardness increased. Considering organoleptic properties, soybean oil improved the extent of spiciness, while the general consumer acceptance was the most favourable (within complemented samples) by 3% flaxseed oil. Increasing vegetable oil levels intensified the taste of spice mixture.
The effects of red grape, wild grape and black raspberry wines on the quality of ground pork during a 15 days refrigerated storage period were investigated. The levels of phenolic compounds were the highest in black raspberry wine (P<0.05). In contrast, the antioxidant capacities according to ferric reducing antioxidant potential (FRAP) and trolox equivalent antioxidant capacity (TEAC) were not significantly different among the wines (P>0.05). The addition of 5% and 10% wine influenced the quality of ground pork by decreasing pH, inhibiting the progression of lipid oxidation and the formation of total volatile basic nitrogen (TVB-N), and stabilizing the red colour of the ground pork compared to control samples to which no wine was added. In ground pork, addition of red grape wine led to lower concentrations of thiobarbituric acid reactive substances (TBARS, 0.19–0.39 mg kg−1) and TVB-N values (69.1–119.9 mg kg−1) than wild grape (0.16–0.43 mg kg−1 and 72.0–194.1 mg kg−1, respectively) or black raspberry wine (0.33–0.58 mg kg−1 and 81.7–225.4 mg kg−1, respectively) up to 10 days of storage. Results from the present study suggested that the quality of ground pork was affected by wine type and storage period. These effects could be due to phenolic compounds as well as other chemical components of the wines.
Authors:K. Halász, A. Geösel, J. Szarvas, N. Virágh, Cs. Hajdú and N. Lukács
Mycoviruses are known to infect fungi of different habitats and life style. Some of them, like the Mushroom Virus X (MVX) complex, cause abnormal development of fruiting bodies and severe yield losses in mushroom cultivation. Most mycoviruses have a double-stranded RNA (dsRNA) genome, therefore dsRNA-detection is frequently used as a first step to identify virus infection. In relation with MVX 23 dsRNAs species have been described, occurring in variable number and combination in diseased mushrooms. The aim of our experiments was to find out whether dsRNA-immunoblotting can be used to detect dsRNA in small samples of cultivated A. bisporus varieties and of wild growing Agaricus species. We found that by immunoblotting, the same dsRNA species were detected in apparently healthy cultivated champignon fruiting bodies and in MVX-infected reference samples, respectively, as by conventional CF11 chromatography, but for immunoblotting a much smaller sample size was needed. In two out of three deformed fruit bodies of cultivated A. bisporus from Hungary we detected a 4.1 kbp dsRNA species which was also present in the MVX infected reference samples. Diverse and variable dsRNA patterns were observed in apparently healthy samples of 12 wild growing Agaricus species, indicating that extreme care should be taken when non-cultivated Agaricus is used for breeding new varieties. Non-sterile cultures and environmental mushroom specimens are fairly often mixed with parasitic and endofungal organisms, therefore, we also tested fungi isolated from mushroom cultures. Here again, 1–7 dsRNA species were found in extracts of Trichoderma and Dactylium isolates and of Mycogone-infected sporophores. Our results demonstrate clearly that dsRNAs from very different origins can be present in cultivated champignon and support the view that the MVX symptom-associated dsRNAs are probably of polyphyletic origin and do not represent one defined virus.
Lactic acid bacteria in fermented foods help in the improvement of flavour, preservation of the nutritive values of the raw material, and inhibition of growth or killing of food spoilage and pathogenic bacteria. Beside other metabolites, the produced bacteriocin, which is a ribosomally synthesized antimicrobial peptide, is the major metabolite involved in the killing of food spoilage microorganisms and acts as a biopreservative. In search of a bacteriocin having specific inhibitory activity against food pathogenic bacteria, isolation of bacteriocin producing lactic acid bacteria from various food items was carried out. Based on maximum production of the bacteriocin, strain BS13 was characterized and was further identified as Enterococcus faecium BS13 on the basis of physicochemical properties and 16S rRNA analysis. In MRS medium this isolate presented the maximum production of bacteriocin (27 306 AU ml−1) after 18 h of incubation period. BS13 bacteriocin showed antimicrobial activity against a wide range of bacteria, including Bacillus subtilis, Staphylococcus sp., Pediococcus sp., Listeria monocytogenes and Lactobacillus sp.
Considering a stiffened panel made from an elastic homogeneous and isotropic material which suffers a single localized initial geometric imperfection, assessment of the buckling limit state under in-plane uniform axial compression in the direction of stiffeners was performed. Giving a topological configuration of the stiffened plate, focus was aimed at the combined effect resulting from geometrical dimensions and localized defect characteristics. The perfect stiffened plate taken as reference and diverse imperfect stiffened plates suffering a single localized initial geometric defect of the form of a square depression were analyzed in this work. Extensive parametric finite element simulations were performed according to full factorial design of experiment tables that were built on key intervening factors. It was found that the main parameters controlling the buckling stress for the perfect plate are the plate width, then the web height and width, then finally the interaction between plate width and web height. In case of imperfect plates, the most adverse situation was obtained with the defect placed on the intermediate segments of the stiffened plate. A reduction of the buckling stress as low as 56% was reached in this situation. The main factors influencing the buckling load for the imperfect plate differ according to the defect configuration.
Authors:I. Fazekas, Gy. Szabó, Sz. Szabó, M. Paládi, G. Szabó, T. Buday, Z. Túri and A. Kerényi
The aim of our report is to refer on the actual state of small biogas power plants in Hungary summarising the increase in their number and capacity and their effects on climatic change. The above is based on the CO2 emission of the energetic utilization of biogas and the calculation of its ecological footprint that were compared to the environmental effects of natural gas energetic utilization. The aim of this paper does not include the complete life cycle analysis therefore the environmental benefits of the energetic utilization of biogas produced from various raw material are presented via only the direct CO2 emission of the production process.
The article presents environmental analysis of a detached house in terms of its life cycle. The analysis is simplified in order to compare the built and operational energy of the building whereas the operational energy is described using computer aided building performance simulation. The input data related to the built (embodied) energy are based on information from classical works on life cycle analysis. The article also justifies the simplification of environmental analysis, which aims to build pragmatically on existing standardization and legislation on energy performance of buildings. The final section provides some considerations concerning the environmental assessment of buildings.
Taking into consideration that more than 40% of the final energy consumption of the EU stems from the residential and commercial building sector, it is not surprising that the community-level regulation strongly focuses on these sectors (Eurostat, 2011). In respect to buildings’ energy performance, the European Parliament and the Council Directive 2010/31/EU on the energy performance of buildings requires from Member States (hereinafter: MS) to ensure that, by 31 December 2020, all new buildings are to be nearly ‘zero-energy’ buildings. Furthermore, MSs shall ensure that energy performance certificates are to be issued for buildings constructed, sold or rented out to a new tenant. Although the concerning regulation is being developed in the right way, several corrections are still required from an ecological point of view.
Authors:G. Kozma, E. Molnár, K. Czimre and J. Pénzes
In our days, energy issues belong to the most important problems facing the Earth and the solution may be expected partly from decreasing the amount of the energy used and partly from the increased utilisation of renewable energy resources. A substantial part of energy consumption is related to buildings and includes, inter alia, the use for cooling/heating, lighting and cooking purposes. In the view of the above, special attention has been paid to minimising the energy consumption of buildings since the late 1980s. Within the framework of that, the passive house was created, a building in which the thermal comfort can be achieved solely by postheating or postcooling of the fresh air mass without a need for recirculated air.
The aim of the paper is to study the changes in the construction of passive houses over time. In addition, the differences between the geographical locations and the observable peculiarities with regard to the individual building types are also presented.
Sida hermephrodita or Virginia mallow is a perspective perennial herb in the Malvaceae family able to yield a biomass crop through the last two decades. Additionally, the plants have a lot of uses and benefits for instance it can be used as a fodder crop, honey crop, ornamental plant in public gardens. It has favourable features for example fast growing and resistance against the disease and climatic fluctuations, etc. Since Sida is in the beginning phase of domestication, it has a serious disadvantage: the low and slow germination as a big part of wild plants. Due to the expressly low germination percent, the need of seed showing of driller should tenfold 200 thousand seeds/acre instead of 10–20 thousand, which is not available and expensive. Therefore the practical purpose of our research of seed physiology was to increase the seed germination percent in the available, basically wild Sida population. In the first stage of our experiments we examined two factors relating to seed germination percent and seed germination power during our research: the influence of hot water treatment and the effect of exogenous or endogenous infection of seeds. However, in our germination tests, utilizing the scarified seeds with hot water (65, 80 and 95 °C), from 29.3% to 46% germinated from those samples, which were collected from the population of S. hermaphrodita in Debrecen. The average germination for all season was 5–10% without treatment and rinsed using hot water up to almost 50%. When applying physically scarified use, the oldest seeds showed the best germination (46%) after the hot water operation in spite of the previous studies. We discovered that there is a close relationship between the collecting time of the seeds and the ration of seed infections, as well as germination percentage. Thus, the 2009 season was the most favourable in case of contamination (control: 17.3% and 80 °C treatment: 0%) as well as germination percent. It could be concluded that the best season for our findings was 2009 due to autumn harvest of Sida seeds. In our opinion, the autumn harvesting should be the best time to overcome the problem of the low germination and high infection percentage. We also discovered that apparently there is a close relationship between the seed fresh weight or water uptake capability and the percentage of infection. Following these recognitions, we modified our technique in such a way that we fractionated the seeds based on their fresh weight / or relative density before we carried out the treatment. When we filtered the floating seeds on the surface of water, the hot water treatment was performed considerably better on the sunk seeds after separation. Therefore by this special priming process, we were able to reach 80% germination capacity of Virgina mallow seeds under laboratory conditions (26 °C without illumination).
Nowadays, the problem of energy poverty occurs more and more frequently and its solution is a serious and urgent task. Energy poverty is closely related to the poor energy performance of residential stocks. Energy poverty is simultaneously an energetic and social question, due to involving households having bad energetic parameters. Because of bad efficiency, the energy costs are highly related to earnings. It is not able to enhance the energy efficiency of buildings. Financial supports for endangered layers should contain measures to increase energy efficiency and decrease energy consumption. However, the concept of energy poverty is applied to social groups, like families or communities. In this paper, we extended the concept of energy poverty to SME (small- and medium-sized enterprises). The paper introduces the concept and the risk of energy poverty and the technology of measuring those risks.
As it is well known that due to the continuously decreasing trend of the alternative energy technologies and the increase in the costs of the traditional fossil fuels, the development of resident or commercial buildings with greatly reduced energy needs becomes a high ranked and more pressing scientific challenge. In topic with this technological and scientific provocation, the paper presents a LabView software-based building supervising and events monitor system designed and developed with the basic purpose to serve as support for net zero-energy control strategies implementation in intelligent buildings. Afterwards a brief presentation of the adopted intelligent building development strategy and the net zero-energy concept are presented and discussed. Once these theoretical aspects have been expressed and clarified, a multi-layer type implementation is unfolded, where the background layer is a building supervising and events monitor system. The main software development steps of this system are presented in details to prove the feasibility and reliability of the adopted implementation strategy.
The recast of the Energy Performance Building Directive contains a new article about the need to increase the number of buildings which go beyond current national requirements, and to draw up national plans for increasing the number of nearly zero-energy buildings (nZEB) with the final target that by 2020 all new buildings shall be nearly-zero energy. Nearly zero-energy buildings are buildings with a very high energy performance, where the remaining low energy demand can be supplied to a significant extent by renewable energy.
In this paper, a detached house complying with the proposed Hungarian nZEB requirements is analysed. The life cycle cost and life cycle environmental impacts of the building are assessed for various building service systems to optimise the building design.
These days, the investigations of the physical properties of the insulating materials are very important. In this paper we report the measured water uptaking capabilities of a thermal insulating paint. They can be found in liquid phase, but we measured dried solid samples. The thin thermal insulators (insulator coatings) are starting to spread on the market of the building materials. The proper understanding of sorption behavior of the materials is important from the applied building technology point of view. Moisture sorption and desorption measurements were carried out on two samples with different geometry by using climatic chamber method. After drying the samples at 90 °C for one hour in the Venticell 111 type drying equipment they were wetted with a Climacell 111 type climate chamber, where the relative humidity (RH) was varied from 25% to 90% at 293 K for 2 hours. The samples were wetted for 2 and 4 hours as well. Sorption and desorption as well as kinetic curves are presented in this paper.
With the need to increase the use of renewable resources to reduce environmental impacts caused by greenhouse gases, there will be a global necessity for more intense use of renewable energy. In addition, given that a large part of energy in Latvia is imported, it is necessary to develop domestic energy supplies, thus ensuring self-sufficiency and to reduce the dependence on external factors. One of the potential sources of renewable energy that could be used increasingly is biogas. Biogas production through anaerobic digestion is considered to be an optimal solution of different types of organic waste, converting these waste materials into renewable energy and organic fertilizer. However, the lack of existing effective biogas transmission and distribution network lead to the tendency to utilize the energy near the plant site often has low efficiency, therefore cannot serve as a viable long-term source of energy.
In areas where large biogas plants are present and they account for a significant share of primary energy also where natural gas transmission networks are nearby, a possible solution would be upgrading biogas to the required level, and then using it in mix with the natural gas. Before this process is carried out, the assessment of possible economic benefits must be done, as biogas plants are mostly decentralized with relatively low energy capacity. In this paper biogas and natural gas chemical differences are analyzed. Furthermore, the possibility of biogas usage combined with natural gas and the economic benefits of such a process in case of Latvia is discussed.
Authors:S. Samagassi, A. Khamlichi, A. Driouach and A. Limam
In this work, reconstruction of pressure time signal rising during a non-punctual impact occurring on an elastic structure has been achieved through using direct Bayesian approach. This was performed by means of posterior distribution of probabilities integrating the likelihood and prior random information. In the case of a noisy linear system for which the densities of probabilities associated to the prior information and noise could be assumed to be Gaussians and mutually independent, a new algorithm consisting of two steps was proposed. The first step works like a Wiener filter action and enables to determine the input pressure mean, while the second step yields evaluations of variability of the input pressure signal around that mean. It was found that the proposed method achieved perfect reconstruction of the original pressure taken at the input of the system.
Energy efficiency measures and the enhancement of investments in renewable energy play important role in sustainable development and lead to advancement of competitiveness of national economies. The increase of renewable energy consumption and the reduction of greenhouse gas emissions are significant stages of the process to achieve the main purposes of sustainable development at global and national levels.
In this paper the change in the share of renewable energy in gross final energy consumption and in the greenhouse gas emissions intensity in Hungary between 2004 and 2011 is investigated.
It is demonstrated that the share of the renewable energy in gross inland energy consumption increased during the examined period. The measure and the tendency of the change in Hungary show similarity to the EU 27 average.
The greenhouse gas emissions intensity of energy consumption decreased in Hungary between 2004 and 2011. According to the data, the decrease is the second largest among the European Member States.
Authors:J. Soós, Sz. Kozits, Z. Kovács, E. Várvölgyi, D. SzöllőSi and A. Fekete
Nowadays quality measurement is an important topic in food quality control. The electronic tongue (ET) can be a useful tool in this feld. The objective of our work is to demonstrate the application potential of ET for the evaluation of different coffee, wine and carrot juice samples and to compare the results with sensory attributes. ET was able to distinguish the different coffee samples. The Arabica concentration of the samples were predicted with close correlation (R2=0.98) and low error (RMSEP=3.16). The Arabica content of commercial samples were also determined. The ET measurement results of different wine samples showed a tendency similar to the increasing ‘acidic content’ determined by sensory evaluation. The closest correlation between ET and sensory evaluation was found with the ‘acidic taste’ (R2=0.87) and the lowest prediction error was observed with the prediction of ’fruit taste’ (RMSEP=6.11). Carrot juice samples were also distinguished by ET. Sensor SRS, developed for sour taste, gave the highest correlation (r=−0.99) with the sour taste of the carrot juice samples. The conclusion is that ET is a useful instrument in the feld of food quality control when appropriate statistical methods are applied.
Authors:T. Ábel, A. Blázovics, A. Wimmer, G. Bekő, B. Gaál, B. Blazics, M. Eldin, J. Fehér, I. Szabolcs and G. Lengyel
The effect of moderate alcohol consumption on insulin sensitivity is actually a topic of intense research nowadays. In this study we investigated the effect of moderate consumption of white wine in subjects with metabolic syndrome. Thirty-two patients with metabolic syndrome participated in this prospective, randomised, double-blind study. The subjects received either Müller-Thurgau (n=14) or Pintes (n=18) sort of wine for 4 weeks. Male and female subjects consumed 300 ml wine (30 g alcohol) and 200 ml wine (20 g alcohol) per day, respectively. Clinical and laboratory parameters were determined before and after the period of wine consumption. The HOMA-IR showed a significant decrease upon the consumption of both sorts of wine as compared to the baseline (Müller-Thurgau group: 1.85±2.1 vs. 1.06±0.6; P=0.03; Pintes group: 2.28±2.04 vs. 1.08±0.6; P=0.002). Four weeks of wine consumption lead to significant decreased of ALT (alanine aminotransferase; Müller-Thurgau group: P=0.003; Pintes group: P=0.002) and AST (aspartate aminotransferase; Müller-Thurgau group: P=0.003; Pintes group: P=0.02). Epidermal growth factor (EGF) levels increased significantly in both groups (Müller-Thurgau group: P=0.004; Pintes group: P=0.001). The plasma reducing capacity increased significantly upon the consumption of both sorts of wine (Müller-Thurgau group: P=0.002; Pintes group: P=0.001). In patients consuming Müller-Thurgau there was a significant decrease of total cholesterol (5.4±1.4 vs. 4.9±1.2 mmol l−1; P=0.006) and LDL-cholesterol (3.9±1.1 vs. 3.6±1.2 mmol l−1; P=0.04) levels. In the Pintes group we found no significant difference either in total cholesterol (5.1±0.6 vs. 5.0±0.7 mmol l−1; P=0.25) or LDL-cholesterol (3.6±0.6 vs. 3.6±0.6 mmol l−1; P=0.5) concentrations. The results of our study confirm that moderate consumption of white wine increases insulin sensitivity and EGF levels in persons with metabolic syndrome.
Authors:K. Dénes, Cs. Farkas, Á. Hoschke, J. Rezessy-Szabó and Q. Nguyen
Effects of mixed cultures of Saccharomyces cerevisiae Levuline FB — higher ethanol tolerance — and different Kluyveromyces strains — higher inulinase activity — on the production of ethanol from Jerusalem artichoke extract were investigated. Among the investigated strains, combination of S. cerevisiae and K. marxianus strain Y00959 with simultaneous saccharification and fermentation gave the best efficiency (76%) of bioconversion. The optimal ratio of mixed cultures was determined to be 1:1 of K. marxianus and S. cerevisiae. Central composite design (CCD) was adapted to find the optimum initial substrate concentration and inoculum size for the maximal production of ethanol from Jerusalem artichoke juice. The optimum fermentation conditions were found to be 24% (m/w) substrate concentration and 45 OD600nm ml/100 ml inoculum size of mixed culture. Use of these conditions, about 10.67% (v/v) was produced at 148 h of alcoholic fermentation given. Results of this work provide benefits of mixed culture on production of bioethanol from Jerusalem artichoke.
Effect of nitric oxide and putrescine on postharvest life and quality of strawberry (Fragaria×ananassa Duch. cv. Selva) fruit was studied. Fruits were treated with nitric oxide (at 0, 3, 5, and 8 μmol l−1) and putrescine (at 0 and 2 mmol l−1) and stored at 2.5 °C with 85–95% RH for 15 days. Fruit quality attributes, including firmness, vitamin C content, total soluble solids, total phenolics, colour, total acidity, overall quality, and decay index, were evaluated throughout the cold storage. Both nitric oxide and putrescine effectively maintained fruit firmness, soluble solids content, vitamin C, red colour, total phenolics, total acidity, and overall quality. Postharvest treatment of strawberries with 5 μmol l−1 nitric oxide effectively controlled decay organisms and retained fruit quality during 15 days of storage at 2.5 °C. Putrescine effectively enhanced the effects of nitric oxide in maintaining fruit quality indices.
Authors:M. Karwowski, M. Masson, M. Lenzi, A. Scheer and C. Haminiuk
This study assessed the rheological behaviour, physical stability, and the phenolic compounds of Eugenia pyriformis Cambess. (uvaia) and Eugenia uniflora L. (pitanga) fruits. The effect of temperature on the rheological behaviour of the fruit was evaluated (10–60 °C) by means of non-oscillatory rheological analysis in a rheometer. The whole samples (purée) exhibited shear-thinning behaviour (n<1), whereas the centrifuged samples exhibited Newtonian behaviour (n=1). The Arrhenius equation accurately described the effect of temperature on the apparent viscosity of the fruit. The stability study was performed by means of sedimentation and turbidity testing. The stabilisation of purées occurred on the second (Eugenia pyriformis Cambess.) and on the third (Eugenia uniflora L.) day of storage. The results demonstrated that turbidity increased with an increase in homogenization velocity. The phenolic compounds of the fruit were identified and quantified by reverse-phase high-performance liquid chromatography (RP-HPLC). The samples presented significant differences in the concentration of phenolic compounds. Among the phenolic acids identified, gallic acid was the one with higher concentration in both fruit assayed. Comparing the fruits, it was observed that Eugenia pyriformis presented higher content of flavonoids (5-fold) and Eugenia uniflora presented higher content of phenolic acids (8.5-fold), especially gallic acid. Myricetin and quercetin were the main flavonoids determined in Eugenia pyriformis.
Authors:M. Abu-Darwish, M. Gonçalves, C. Cabral, C. Cavaleiro and L. Salgueiro
Juniperus phoenicea L. (Cupressaceae) is an evergreen small tree or shrub, distributed throughout the Mediterranean area from Portugal to Israel and North Africa. J. phoenicea has been used for centuries in traditional medicine and its berries are widely used in flavours, perfumes, and to aromatize alcoholic beverages.The aim of the present work was to evaluate the chemical composition and antifungal activity of essential oils of Juniperus phoenicea berries from Jordan.The essential oils of the berries were isolated by hydrodistillation and analysed by GC and GC-MS. Minimal inhibitory concentration (MIC) and minimal lethal concentration (MLC) were used to evaluate the antifungal activity of the essential oils against dermatophytes, yeasts and Aspergillus species.The essential oils were characterized by high percentage of α-pinene (75.5 and 84.2%), which distinguish them from oils from other countries where α-pinene is usually present in lower percentages. Essential oils exhibited high antifungal activity against dermatophytes and Cryptococcus neoformans with MIC values ranging from 0.32–2.5 μl ml−1.These results support that essential oils from J. phoenicea berries may be useful in the treatment of dermatophytosis. Further studies should be stimulated in order to evaluate toxicity and optimal concentrations for clinical applications.
The characterization of four types of Indian honeys (Trifolium alexandrinum (berseem clover), Brassica sp. (mustard), Helianthus annuus (sunflower), Eucalyptus lanceolatus) was carried out on the basis of their quality parameters (moisture, pH, free acidity, reducing sugars, sucrose, fructose/glucose ratio, colour, ash content, proline content, invertase activity, diastase activity, hydroxymethylfurfural (HMF), and mineral content (sodium, potassium, iron, calcium, zinc, and copper). The source of honey had a significant (P<0.05) effect on moisture content, free acidity, pH, reducing sugar content, fructose/glucose ratio, hydroxymethylfurfural content, invertase and diastase activities, sucrose content, proline, ash content, and mineral content. Pattern recognition methods, such as principal component analysis and linear discriminate analysis, were performed to classify honey on the basis of physicochemical properties and mineral content. The variables calcium, pH, and potassium exhibited higher discrimination power.
The aim of this study was to develop an accurate, fast and safe routine diagnostic method based on protein studies for differentiating between T. caries and T. controversa at species level. Since import of wheat contaminated with T. controversa is restricted by several countries, differentiation of T. controversa from the more prevalent T. caries is of economic interest. The newly developed method is based on distilled water washing followed by the rupturing of the teliospore walls in PBS extraction medium, and an SDS electrophoresis (10% resolving gel). The electrophoretic pattern showed consistent species-related differences in a 106 kDa polypeptide that appeared in each extract of T. controversa, but was not present in the protein extracts of T. caries. The newly developed method could be of value for the authorities performing routine monitoring of T. controversa as an up-to-date diagnostic assay in wheat shipments.
In this study, detection of an obligate aerobic, thermophilic and acidophilic bacterium, the sporeforming Alicyclobacillus acidoterrestris was performed by determination of its specifc metabolite, guaiacol. Since its spores have been shown to resist conventional pasteurization, it has become a potential spoilage concern for fruit and vegetable juices, mainly for apple and orange juices. Detection of guaiacol was carried out by using an NST 3320 type electronic nose, and other methods, such as peroxidase-based enzymatic method with UV-Vis spectrophotometer, SPME-GC-MS technique and an untrained sensory panel were also applied. The results indicated that based on their detection limit the methods can be ordered in the following way: SPME-GC-MS (detection limit: <0.5 ppm)<sensory evaluation (detection limit: 0.5–1 ppm)<spectrophotometric method=electronic nose technique (detection limit: 1.25–2.5 ppm).
Authors:S. Emen Tanrikut, B. Çeken, S. Altaş, M. Pirinççioğlu, G. Kizil and M. Kizil
Rheum ribes L. (Polygonaceae) is a common species of rhubarb in Turkey, which is also found in Iraq, Iran, Pakistan, Afghanistan, and Russia. The antioxidant potency of stems was investigated employing various in vitro systems, such as lipid peroxidation in rat brain homogenate, 1,1-diphenyl-2-picrylhydrazyl (DPPH) and superoxide anion radical scavenging, ferric reducing power, metal chelation activity. R. ribes stem parts showed strong inhibitory activity toward lipid peroxidation of rat brain homogenate induced by the FeCl3-ascorbic acid system. R. ribes extract was able to reduce the stable free radical DPPH 83.9±1.90% at 150 μg ml−1. The reducing power of the extract was 0.46±0.074 at 250 μg ml−1. The effect of extract of R. ribes on DNA cleavage induced by UV-photolysis of H2O2 using pBluescript M13+ plasmid DNA was also investigated. This extract significantly inhibited DNA damage induced by reactive oxygen species (ROS). These findings demonstrate that aqueous extract from fresh stems of R. ribes has antioxidant activity and thus have great potential as a source for natural health products.
Authors:Á. Vajda, I. Zeke, R. Juhász, J. Barta and Cs. Balla
The aim of the present study was to examine the infuence of hydrolyzed, nanofltered concentrate of the ultrafltered permeate (HNF concentrate) of acid whey on the quality characteristics of milk-based ice cream. Thermophysical properties were determined by differential scanning calorimeter, consistency was measured by oscillatory rheometer, and sensorial quality was evaluated by scoring method. It was concluded that the acid whey did not increase the melting of the product, and reduced the freezing point. Cryoscopic temperature, onset point, and glass transition temperature (Tg) gradually decreased as the quantity and proportion of acid whey increased in the ice-cream. Rheological results indicated that using HNF, acid whey produced more creamy and smooth ice-cream. However, because of its characteristic taste, maximum 20% of milk could be replaced by HNF acid whey in milk-based ice-creams.
Eight Lactobacillus, five Saccharomyces and one Streptococcus strains were chosen to perform mono and mixed culture fermentations, focusing on interaction investigation via agar diffusion and analysis of cell growth kinetics, both serving as selection criteria. Mixed culture fermentations with four lactic acid bacteria (Lb. bulgaricus, Lb. paracasei SF1, Lb. plantarum 2142, and Lb. casei Shirota) and four yeast strains (S. cerevisiae W66, S. cerevisiae WS34/70, S. cerevisiae W120, and S. carlsbergensis 843) were performed in wort with initial cell ratio of 1:1. It was determined that during fermentations, cell concentration of lactic acid bacteria exceeded that of yeasts by one order of magnitude. Three strain combinations (S. carlsbergensis with Lb. bulgaricus, Lb. 2142, and Lb. Shirota) were chosen for further fermentations. Basic behaviour of them in wort was studied in mono culture, which helped to determine interaction type between bacteria and yeast in mixed culture. It resulted in higher Lactobacillus cell concentration in mono cultural than in mixed culture fermentation, which refers to competition. Cell ratio was changed to 1:10 (lactobacilli:yeasts), to favour growth of yeast and avoid lower pH. Despite the higher initial concentration of yeast, results turned in favour of lactobacillus already at the 24th hour.
Authors:D. Nagy, M. Krassóy, I. Zeke, K. Pásztor-Huszár and Cs. Balla
The aim of the study was to select the most suitable freezing and thawing method for preserving the quality of pasta flata type Parenica cheese comparing different methods: slow, shock (circulated air) and cryogenic freezing and thawing at room temperature and in a refrigerator, respectively. To observe the effects of these methods on some cheese properties weight, pH, and dry-matter content were measured, stringiness was examined, and compression test were performed for texture analysis. Thermophysical properties were determined by DSC: unfreezable water content, onset point of melting, and latent heat. Sensory analyses were also carried out by profle analysis. Results of objective and subjective measurements showed similar trends: characteristics of cheese samples frozen in circulated air and thawed in refrigerator resembled the most to the control sample.
Authors:O. Csernus, I. Bata-Vidács, J. Farkas and J. Beczner
The effect of water activity (0.85–0.99 aw) and temperature (20–35 °C) on growth of two potentially toxigenic moulds, Aspergillus niger and Penicillium expansum, were studied. On the basis of the measured colony diameter ComBase DMFit program was used to estimate the lag phase and growth rate. Similar results may provide basis for the risk assessment of fungal growth (and also for the possible mycotoxin contamination) in food and feed plants in the vegetation season due to the climate change (global warming), and also during unfavourable storage conditions.
Authors:G. Jurak, J. Bošnir, D. Puntarić, I. Pavlinić-Prokurica, Z. Šmit, H. Medić, I. Puntarić and E. Puntarić
The aim of the study was to determine the possible presence of N-nitrosamines in liver pâtés available on the Croatian market and to compare them with a liver pâté from the EU market. In addition, the effects of temperature and length of storage on N-nitrosamine concentrations were assessed. A total of 630 samples were randomly chosen. Thirty samples of each were analysed immediately upon sampling, whereas another 30 samples were stored for 5 and 10 days at 4 °C, 22 °C and 37 °C, respectively. In the samples stored at 4 °C, the mean total N-nitrosamine level was 1.3–6.8 μg kg−1 on day 5 and 1.0–5.0 μg kg−1 on day 10. In the samples stored at 22 °C, the mean total N-nitrosamine level was 3.6–9.3 μg kg−1 (day 0), 11.9–24.5 μg kg−1 on day 5, and 22.7–32.3 μg kg−1 on day 10. In the samples stored at 37 °C, the mean total N-nitrosamine level was 104.9–231.1 μg kg−1 (day 5) and 801.3–1329.0 μg kg−1 (day 10). Temperature and length of storage were found to be associated with the formation of N-nitrosamines in meat products, but carcinogenic N-diethylnitrosamine (diEt) in particular, accidentally or not, was not present at all in the products originating from the EU.
Authors:I. Rumora, I. Kobrehel Pintarić, J. Gajdoš Kljusurić, O. Marić and D. Karlović
This study elucidates the key success of using statistical modelling in the design and development of a new product (milk toffee) as potential new functional food product. The standard milk toffee recipe was modified in order to produce new products with less sugar, more inulin, and decreased energy content. From the consumers point of view, a product has to be healthy (acceptable ingredients like low sugar content or inclusion of inulin) and tasty (good sensory properties). This is an opportunity to use chemometric strategies that can highlight information in relation to different ingredients and preferable taste attributes. Multivariate exploratory techniques were used in order to detect relationship between the milk toffee ingredients (sugar, water, condensed milk, glucose syrup, fat, salt, sorbitol, and emulsifier E 471) and sensory attributes of taste and texture (sweetness and hardness) chosen for this research.Results showed that the sweetness is a direct outcome of added sugar, glucose syrup, and condensed milk, and the hardness, as the next important sensory attribute of a milk toffee, is positively correlated with the content of fat, glucose syrup, water, salt, and E 471. Statistical modelling proved to be a useful tool for elucidating the relationship between ingredients and sensory properties of the milk toffee and can be a useful tool in the complex interpretations of changes in product design and development.
Authors:D. Varga, Cs. Hancz, P. Horn, T. Molnár and A. Szabó
Four important Hungarian common carp (Cyprinus carpio L.) breeds (Attala mirror, Attala scaled, Hortobágy scaled and Szeged mirror) harvested from different fish farms were analysed in this study. Main body indices, slaughter characteristics, fillet fat content, and conventional fish flesh quality characteristics were measured and compared. The slaughter value of the mirror strains tended to exceed that of the scaled type carps. For the calculated body indices (profile, cross-sectional, head and tail index) the influence of strain was statistically proven. Fillet fat content was significantly (P<0.01) affected by strains/ponds. The pH value of the fillet was significantly influenced by the strain as a fixed factor. Large, strain dependent variability was proven in fat content besides identical fillet dry matter contents. It was assumed that culture conditions and strain largely influence and lead to a marked variability of the body composition and flesh quality of the most important Hungarian fish species.
The surface microbial contamination is of great interest, since these microbes can be potential sources of food-borne diseases. The purpose of this study was to determine and compare the microbial surface contamination of sour cherry (Prunus cerasus L.) produced by integrated and organic cultivation methods in Hungary. The effects of the growing area, year, and cultivar were studied on 62 samples. According to the results, the average microbial contamination of sour cherry is within a certain range, independently from the cultivar, growing area, and year. The frequency distribution of the surface bacterial, mould and yeast counts also did not show significant differences between the growing methods or cultivars. Principal component analysis ranked the sour cherry samples into seven groups on the basis of the level of microbial contamination. The discriminant analysis proved the correctness of the grouping. The grouping was independent from cultivars, growing methods, and years. No examined food-borne pathogen Salmonella spp. or Listeria spp. were found on the surfaces of sour cherry.
Authors:A. Sebestyén, Zs. Kiss, B. Vecseri-Hegyes, G. Kun-Farkas and Á. Hoschke
Currently gluten-free beer is not produced in Hungary for coeliacs. The goal of our research was to develop brewery products made of domestically grown millet (Alföldi 1) and buckwheat (Oberon) that are similar to traditional beer of barley malt regarding taste, aroma, consistency, colour, foam stability and alcohol content.On a micromalting equipment malts were made of buckwheat and millet. Beer was produced on pilot plant scale (50 l) with decoction process (mashing program with rests at 50 °C, 65 °C and 72 °C) and was supplemented with a highly heat-stable bacterial α-amylase, a fungal α-amylase and β-glucanase. Malts were evaluated by congress mashing (extract content, extract difference, pH, and colour); wort and final beer analyses were performed as well (pH, extract, iodine test, FAN, colour, bitterness, alcohol and extract content). Finally, sensory characterization was carried out. Difficulties with lautering were encountered during the brewing process with buckwheat. The analytical results indicated that the buckwheat and millet beer had different values compared with a typical barley beer with regard to pH, FAN, fermentability, and total alcohol. The extracts of the buckwheat and millet wort were lower, resulting in a final attenuation of 61.5% and 73.2%.In laboratory experiments optimal temperature of β-amylase found in domestically grown buckwheat (64 °C) and millet (62 °C) was determined by detecting maltose production with HPLC. Data was used to set the rest temperature of the enzyme during mashing. Inhibiting effect of certain substances on proteolytic enzymes was investigated by measuring the extract, FAN, and soluble nitrogen contents. Inhibition was detected in case of both raw materials, although to a different extent. Inhibition is influenced by tannins and polyphenols found in the grain (Chethan et al., 2008).
The objective of this work was to assess the impact of various NaCl concentrations on Lactobacillus rhamnosus OXY viability after freeze-drying. Osmotic stress was applied during the exponential growth phase of bacterial culture. At salt concentrations between 0.2–0.5 M, a high biomass concentration and a significant increase in cell viability after lyophilisation was observed. An analysis of two-dimensional protein gels indicated the presence of shock proteins, for example, GroEL, ClpB, DnaK, TF, which provide resistance during freeze-drying and subsequent storage. On the basis of these results, it is recommended that lactic acid bacteria cultures be sub-lethally treated with 0.5 M NaCl before freeze-drying.
Authors:P. Penksza, R. sárosi, R. Juhász, K. Manninger-kóczán, B. Szabó-Nótin, L. Szakács and J. Barta
The aim of the present study was to investigate whether the Jerusalem artichoke powder produced by a simple drying method is suitable for replacing inulin in dairy products and in fat replacer mixtures. Rheological properties of milk drinks were tested by rotational method measuring the flow curve and fitting the Herschel-Bulkley model. The Jerusalem artichoke powder showed similar rheological behaviour as the commercially available inulin and proved to be a more effective thickener in milk drinks as indicated by the higher consistency values at the same concentration. Panelists found milk drinks prepared with Jerusalem artichoke powder to have similar sensorial quality as prepared with inulin. Fat replacer mixtures were tested by oscillatory tests using amplitude sweep method. The samples containing Jerusalem artichoke powder had lower complex viscosity and initial G’ and G” values indicating weaker gel forming properties compared to inulin. However, lower slope of G’ and G” indicated their better spreadability. The organoleptic texture properties of fat replacer prepared with Jerusalem artichoke powder proved to be slightly better than that of the inulin containing mixture. Based on our results, the Jerusalem artichoke powder seems to be suitable to replace inulin as a natural additive in certain food products.
Recently food-grade microemulsions have been of increasing interest to researchers and exhibited great potential on their industrial applications. The microbiological and quality characteristics of NuoMiGao, a traditional Chinese steamed rice cake, affected by a prepared food-grade monolaurin-containing microemulsion have been evaluated in this study. Microbiological analysis indicated that 0.05% microemulsion was comparable to 0.01% sodium dehydroacetate, extending the shelf-life by two days. The quality analysis showed that the addition of the microemulsion effectively prevented the hardening phenomena in rice cake; the lightness and yellowness were fairly stable while redness increased slightly (P<0.05); the lowered pH value and the prevention of moisture drop in rice cake were in agreement with the microbiological analysis and hardness trends.
Authors:G. Styevkó, Cs. Styevkó, Á. Hoschke and Q. Nguyen
Glycosyltransferase activity of Pectinex ultra SP-L (from Aspergillus aculeatus) commercially available enzyme preparation was studied in mono- and bisubstrate systems using different donors (maltose, lactose, and sucrose) and acceptors (fructose, galactose, glucose, maltose, mannose, xylose, lactose, and sucrose). Oligosaccharides consisting of three monomers were detected in the cases of maltose, sucrose, and lactose as monosubstrates, thus this preparation should contain glucosyl-, fructosyl-, and galactosyl-transferase activity. Generally, yields of oligosaccharides synthesized were higher in bisubstrate systems maltose:sucrose, maltose:lactose, and sucrose:lactose than on monosubstrates. Use of maltose:sucrose bisubstrate resulted new oligosaccharide(s) (fructosyl-maltose or glucosyl-sucrose). The optimal ratio of substrates in the case of maltose:sucrose was determined to be 1:9. Increase of the dry content of the reaction mixture induced the transfer reaction. The highest oligosaccharide content was obtained at 60% (w/v) substrate concentration. In the case of the optimal ratio and dry content, 4.02% (w/v) oligosaccharide (DP3) concentration was achieved. These oligosaccharides may alter prebiotic and biochemical properties in food applications.
Authors:A. Dutta, P. Gope, S. Banik, Md. Rahman, S. Makhnoon, M. Siddiquee and Y. Kabir
Milled rice from nine aromatic cultivars was evaluated for physicochemical, cooking, and antioxidant properties. Physical parameters measured were milling outrun, head rice yield (HRY), and appearance (size and shape). Cooking time, water uptake ratio and elongation ratio were determined to study their cooking quality. Chemical parameters included were amylose content (AC), protein content (PC), gel consistency (GC) and alkali spreading value (ASV). Total phenolic content (TPC) was measured using the Folin-Ciocalteu method, while ferric reducing antioxidant power (FRAP), total antioxidant capacity (TAC), and 1,1-diphenylpicrylhydrazyl (DPPH) radical scavenging activity were used to study their antioxidant activity. This study revealed all rice cultivars, except Basmoti-370 and Gopalbhog, showed HRY. Besides, all rice cultivars displayed high protein content. Significant variations (P<0.05) were found in TPC and the antioxidant activities of the rice cultivars. The correlation coefficient between the TPC and the antioxidant activities was strong and statistically significant (P<0.05).
Authors:Ž. Kurtanjek, D. Horvat, G. Drezner and D. Magdić
Gluten proteins composed of gliadins and glutenins are important contributors to the wheat quality properties. Twenty-eight winter wheat cultivars differing in bread processing quality were collected at the experimental fields of the Agricultural Institute Osijek, Croatia, in growing season 2006/2007.The HMW-GS composition and gliadin contents were determined by SDS-PAGE and RP-HPLC, respectively, with the aim to determine their relationship with wheat quality properties. Based on gliadins and HMW-GS data for 28 wheat cultivars PLS models were developed for the prediction of 15 baking quality parameters.NIPALS algorithm was applied for the evaluation of the latent variables and regression coefficient parameters. The obtained 4-th order models have average coefficients of determination R2=0.80.Determined variable importance in projections (VIP) coefficients revealed that HMW-GS data have the dominant influence on the baking quality parameters. For extensographic and farinographic properties the Glu-D1 locus has the main VIP coefficient while Glu-B1 locus is the most important for the indirect quality parameters. The derived PLS models and VIP coefficients could be used in molecular based wheat selection and breeding program.
Authors:D. Radványi, R. Juhász, Sz. Kun, B. Szabó-Nótin and J. Barta
Elderberry pomace, by-product of juice pressing procedure, is still rich in biologically active compounds, especially antioxidants and phenolic compounds. The aim of the present study was to investigate whether elderberry pomace could be utilized as a source of natural colourings and preservatives. By a simple solvent extraction a proper food colouring could be produced from elderberry pomace characterized by similar colour values as pressed elderberry juice. A solvent ratio of 1:20 with 50% ethanol proved to be the optimal solvent extraction method to produce an extract rich in antioxidants showing inhibitory effect against Lysteria monocytogenes and Enterococcus faecalis. In elderberry pomace extract three main phenolic compounds: chlorogenic acid, rutin and coumaric acid have been identifed by HPLC analysis. Based on our results, elderberry pomace, a by-product of fruit processing technologies, seems to be suitable for developing natural food additives after appropriate clarifcation processes.
Authors:E. Bujna, F. Kukovics, Q. Nguyen and J. Rezessy-Szabó
Production of phytase by Aspergillus niger F00735 strain in submerged fermentation was studied. The effects of various natural substrates with different phytate contents on secretion of extracellular phytase were investigated and the rice flour with about 5 mg g−1 of phytic acid was found to be the best one. The repression effect of high levels of phytic acid or inorganic phosphorous in fermentation medium (corn flour, wheat grit, soy flour, etc.) on production of phytase was also observed. The optimal concentration of rice flour as main carbon sourc e was determined in combination with sodium nitrate. The maximal activity (≈1500 U l−1, 1.5 times higher than using basal medium) was achieved on the 7th day in media containing 7.12% (w/v) rice flour and 0.86% (w/v) sodium nitrate. Supplementation of fermentation medium with different surfactants such as Tween series (20, 40, 60, 65, 80, 85) and Triton X-100 up to 0.1% (w/v) had no significant effects on the secretion of phytase enzyme, meanwhile at concentrations higher than 0.2% (w/v), decrease in enzyme activity was observed.
Authors:D. Živković, S. Šobajić, M. Perunović and S. Stajić
The influence of seasonal variations on the chemical composition and composition of fatty acids in five commercially important freshwater fish species from the Danube: white bream, bream, vimba, zope, and Prussian carp, during May, July and September was determined. Changes in the chemical composition of meat of all examined species had the same tendencies. Water and protein content in the meat decreased, while fat content increased. The most frequent fatty acids in the meat of all the examined fish were the following: 18:1 n-9 (oleic), 16:0 (palmitic), 16:1 (palmitoleic), 18:2 n-6 (linoleic), 20:1 (eicosenoic), 20:5 n-3 eicosapentaenoic acid (EPA), 20:4 n-6 arachidonic acid and 22:6 n-3 docosahexaeonic acid (DHA). The content of saturated fatty acids (SFA) ranged from 25.03% to 32.43% and displayed a tendency to increase during the observed period. The total content of the n-6 group in the meat of Prussian carp was higher than in other species, which was probably a consequence of specific diet. The total content of n-3 fatty acids in the meat of white bream, bream, vimba and zope was the highest in May, and it declined during July-September. We can conclude that the meat of white bream and vimba contains high nutritional values in terms of EPA and DHA content. The n-3/n-6 ratio was also very favourable: 0.9 to 2.0 in the meat of white bream, bream, vimba and zope, with a clear downward tendency in the observed period.
Authors:R. Juhász, K. Horváth, I. Dalmadi, É. Andrássy, A. Salgó and J. Farkas
Effect of 60Co irradiation on wheat and white pepper grains were investigated in this study using Rapid Visco Analyser (RVA), near infrared reflectance spectroscopy and differential scanning calorimetry. Functional properties of wheat and white pepper were affected by irradiation indicated by a decrease in viscosity values. It was caused by changes of starch structure confirmed by the NIR spectra changes between wavelength 1560–1620 nm, which is the vibration of intermolecular hydrogen bonded OH groups in polysaccharides. The radiation used did not cause significant changes in the thermal properties. RVA proved to be useful for screening radiation induced changes in dry commodities of considerable large starch content on the basis of their rheological behaviour.
Authors:Á. Nagy, Z. Kovács, D. Szöllösi and A. Fekete
The potentiometric electronic tongue is a new and rapidly developing technique. However, the description of the exact working mechanism is still absent. An important part of this description is the effect of the sample temperature on the measurement results. The paper reported here gives a description of the effect of temperature on results obtained with an α-Astree potentiometric electronic tongue. The yielded model was used to perform a temperature correction as if the samples were measured at room temperature (25 °c).
Cities are responsible for about 30% of the energy consumed worldwide. Since 2007 more than 50% of the world population lives in cities, and urbanization is still growing. The energy-efficiency of cities is gaining greater importance today. The paper examines the possibilities of energy consumption reduction and optimization in cities. Various urban and architectural tools are described below that affect indirectly and directly the energy balance of cities. The possible ways of using renewable energy sources in cities have been analyzed. Ways and means of their use is analyzed in on-site, nearby and off-site systems.
In this study Trapezon’s result is generalized on bending oscillation of beams of constant thickness whose width varies in accordance with a fourth order parabola. The existence of a closed formula is shown, which offers solution not only for a fourth order parabola but for every power function describing the width of the beam. In particular, if the exponent is a power of 2 then also the closed form of the general solution can be given.
Managing waste becomes a much more complex task, when logistic changes have to be implemented to combine selective waste collection, needed to increase the rate of recycling, with traditional residual waste collection. This complexity is complicated further by the ever increasing choices of methods and technologies available for the treatment of collected waste.Using available resources efficiently, minimizing environmental effects and operation costs should be the guiding ideas behind optimization of a waste management system, even though often these ideas are in conflict with each other. In this phase of research those factors which have a major influence on system costs are analyzed.
Development of biomineralizing techniques requires new or borrowed methods, as well as instruments for the evaluation of the efficacy of the biomineralization. The aim of the research was to evaluate the appropriateness of two existing techniques for measuring the surface hardness and material loss of microbially treated porous limestone surfaces. Measurements were done with Duroscope, and with the peeling-tape method. The techniques were tested in a comparison trial, where different bio-based curing compounds were applied on porous Sóskút limestone slabs. Two of the bio-based, and the conventional compounds show higher development in the surface rebound values (86.67 to 201.1%) and higher decrease in material-loss (−39.5 to 96.3%) compared to the control specimen. Through statistical analysis of statistical samples with a high number of results, the suitability of the techniques was evaluated.
The municipality of Gyor participated in the last five years in two Intelligent Energy Europe projects (Pro Motion project, Travel Plan plus project), which aim was to deliver transport-sector energy savings by creating a new approach to site-based mobility management across Europe. During the development of the two projects there has been worked out two Local Travel Plans, one for the residential area Menfocsanak, in the city, Gyor and one for the educational institutions of Gyor. The first one is a so called ‘area travel plan’ and the second one is a so-called ‘work travel plan’. The aims of these studies were to reduce CO2 emission caused by private car users and to promote sustainable mobility choices for the residents of the area and for students. In order to solve the future mobility challenges in a sustainable way it is necessary to analyze the existing travel demand and modal-split caused by target groups (residents and students).It is important to develop Local Travel Plans for residential areas and schools, based on quantitative travel behavior data, which can be used for modeling of current and future transport to provide optimized solutions for daily mobility. It is very important to collect data from various sources according to the needed detail of a Travel Plan.
The energy and climate concept of the flagship research institute of the University of Pécs is the result of a three-stage development. The prototypical structures and building services of the first two concepts were developed in line with the financial circumstances and grants and the rationalized third concept became an object for construction research. Through the expansion of the building services and energy supply systems, the building itself has become a ‘measuring apparatus’ for sustainable building construction.
An essential input for environmental studies, especially for hydrological simulations is the soil information, which is usually provided by spatial soil databases. Despite the growing number of related analyses little is known about the uncertainty associated to databases. This study aimed to evaluate this issue. (i) the World Soil Classification System was used to classify soil horizons of the Unsaturated Soil Hydrologic Database of Hungary, (ii) the resulting soil classes were statistically analyzed, (iii) various static measures were derived and dynamic numerical simulations were carried out to assess the uncertainties of the classification method from hydrologic viewpoint. The results question the reliability of the FAO method.
In working with soft soils from tailings unusual material behavior was observed, which could not be explained, using conventional geotechnical models. Therefore the scope of the research has been widened, and experiments with viscous material models began. The aim of the research was to interpret the rheological models indicating viscous behavior into geotechnical practice and looking up existing geotechnical models, which include viscosity and examining their applicability in everyday praxis.