Phytase is an important feed and food additive, which is used in diets to increase the absorption of divalent ions, amino acids, and proteins in the bodies and to decrease the excessive phosphorus release in the manure to prevent negative effects on the environment. To date, phytase has been mostly produced in solid state fermentations with insignificant production volumes. Thus, there is a need to produce phytase in submerged fermentations, which can be scaled-up for commercial productions. Additionally, optimization of fermentation medium has not been studied well in the literature. Therefore, this study has been undertaken to improve Aspergillus ficuum phytase production in submerged fermentations by optimizing important nutrients in the fermentation medium (glucose, Na-phytate, and CaSO4) using Box-Behnken design of Response Surface Methodology. Also, effects of pH and temperature on phytase activity were studied. Optimum glucose, Na-phytate, and CaSO4 concentrations were determined as 126, 14, and 1.1 g l–1, respectively. Additionally, pH 5.5 and 55 ºC were determined as optimum for the produced A. ficuum phytase activity. Under these conditions, phytase activity was increased to 3.45 U ml–1, which is about 50% higher than the previous results. Furthermore, the lowest activity loss was observed under 4 ºC storage conditions during 1 week of storage.
Authors:A. Apichartsrangkoon, P. Chaikham, T. Pankasemsuk and S. Baipong
This study was to examine how encapsulated Lactobacillus casei 01 combined with pasteurized longan juice colonized a digestive system by using a simulator of the human intestinal microbial ecosystem. The results showed that encapsulated L. casei 01 and longan juice stimulated an increase of colon lactobacilli, bifidobacteria, lactic acid and various short-chain fatty acids for which acetate was substantially present in both colons followed by propionate and butyrate. On the contrary, the treatments triggered off the reduction of faecal coliforms, clostridia, and total anaerobes. To sum up, the denaturing-gradient-gel electrophoresis supported that treatment conditions stimulated diversities of bacteria communities occurring in both colons.
Authors:E. Takács, A. Nagy, É. Gelencsér and A. Székács
Reliable determination of microbial or transgenic Cry toxins is an essential issue in food and feed analyses, and enzyme-linked immunosorbent assays (ELISAs) are the method of choice for quantifying these toxins currently in food and environmental analysis. Internal Quality Control (IQC) is an indispensable method to assess accuracy, precision, and reproducibility of analytical measurements. To assess the utility of the ELISA method, IQC was performed on EnviroLogix Cry1Ab/Cry1Ac QualiPlate ELISA with manufacturer supplied analytical standards. Applicability of negative and positive controls (C− and C+) was examined by Shewhart Control Charts for bias and Control Chart of the Range of Duplicates for precision. Linear regression (up to 5 ng ml−1 Cry1Ab concentration) of the commercial ELISA kit was compared to sigmoid calibration (up to 60 ng ml−1 Cry1Ab concentration). For immunoassay optimization process, possible matrix effects in different liquid and solid vertebrate tissues were examined by determination of the limit of detection values in these matrices.
Previous reports highlighted the onion solid wastes as abundant, residual material that might contain a significant load of antioxidant polyphenols. Although there have been studies pertaining to polyphenol recovery from onion wastes, the effect of temperature has not been adequately addressed. In this line, this study was undertaken with the aim of establishing a correlation between the extraction yield in total polyphenols and the extraction temperature, using acidified aqueous ethanol as the solvent system. Extraction of polyphenols from onion solid wastes was found to obey 2nd-order kinetics. On such a basis, the yield in total polyphenols at saturation could be very effectively determined and correlated with temperature using non-linear regression. The results indicated that the extraction yield at saturation is highly correlated with temperature, following a quadratic function. The extract obtained at optimal temperature (40 °C) had a total polyphenol yield of 21.10 mg gallic acid equivalents per gram of dry weight, and it was further analysed by liquid chromatography-mass spectroscopy to characterise its major constituents. The polyphenols detected were quercetin glucosides, as well as quercetin oxidation derivatives, including certain degradation products and dimers. The outcome of this study outlined that temperatures above 40 °C are rather not favourable for polyphenol extraction from onion solid wastes, as suggested by the model established through kinetics. The extract obtained under optimal conditions contained peculiar polyphenolic composition, not encountered in any other food processing residue.
Authors:Adriana Eštoková, Jozef Oravec and Martina Kovalčíková
The paper presents the results of leachability testing of selected heavy metals from the concrete composites of various compositions in order to assess the degree of a contamination risk of the environment. Tested concrete samples contained various amounts of special ingredients based on the blast furnace slag (65%, 75%, 85% and 95% of Portland cement replacement). Leaching tests have been performed by using distilled water. The concentrations of chromium and barium ions in the leachates were measured after period of 30 and 240 days. Changes in pH and conductivity values in leachates have been also observed.
The first known drawings of machines can be found in warfare-themed manuscripts. The oldest of them dates back to the 14th century, but their proliferation took place in the 15th century. During the century an almost standardized drawing style, vocabulary was developed, which also survived throughout the Renaissance.
Compared to the relatively high number of the survived warfare-related manuscripts that included drawings (their number is above 50), the representation of machines for civil usage is very rare throughout the century, even though the architectural drawings also proliferated during this century, and they also introduced a distinct representation style.
The survived portfolio of the Strasbourg master builder Hans Hammer lies at the intersection of this two disciplines: it includes both machine and architectural drawings in a large number. Given the occupation of the master, it can safely assumed that in contrast to those found in the majority of the contemporary machine drawings, his machines served civil purposes.
In this article the following questions are discussed: how do Hans Hammer’s machine drawings fit in the corpus of the contemporary machine drawings both by drawing style and function; and with which manuscripts can a direct connection be made?
Authors:K. Tiwana, P. Mukhopadhyaya, E. Zalok, D. Van Reenen, C. Copeland and P. Newman
This paper discusses the results of a research project which aimed at determining the hygrothermal (i.e. thermal and moisture) performance of the Canadian wood-frame building envelope construction in the city of Shanghai in China. The performance assessments of the wood-frame walls were conducted using the two-dimensional hygrothermal simulation tool called hygIRC-2D. In this study an in-fill type wall was considered and hygrothermal simulations were carried out for the weather conditions of Shanghai. Investigations were conducted to determine the influence of the vapour barrier, exterior stucco cladding material and different types of sheathing boards on the moisture performance of in-fill walls. Additional simulations were carried out to determine the influence of air leakage on the moisture performance of in-fill walls. The outputs from the simulations were analysed with the help of a hygrothermal response indicator called RHT index. It was concluded that the design of the in-fill wall including a rain screen but omitting a vapour barrier is expected to lead to the maximum reduction in hygrothermal loading when exposed to the weather conditions of Shanghai, China.
Considering the continuous algebraic Lyapunov inequality and equation PA + A*P<0 , PA + A*P=Q, the aim of this paper is to give an algebraic proof of the Lyapunov theorem through mathematical induction. Moreover by the presented algorithm all positive definite solutions of the Lyapunov equation are given in the case, if the right hand side is negative definite.
The contribution of this paper is that the measure of the performance of multistage of 40 kb/s Adaptive Differential Pulse Code Modulation (ADPCM) using signal-to-noise-ratio formula previously derived by AL-Rawi. The multistage performance is tested using QAM signal at data rate of 9.6 kb/s with four types of constellations, rectangular, and (5,11), (4,12), (8,8) circular. The simulation results show that the performance degrades with increasing the number of stages of ADPCM. Also, the performance with circular constellation is better than that with rectangular one.
Shenzhen is one of the most dynamically growing cities in the world with a population of more than 10 million. Situated in the Pearl River Delta (PRD) in China it is in the powerhouse of the global economy. Some decades ago Shenzhen was a small fishing village only, however, after its designation as a Special Economic Zone (SEZ) the city has gone through rapid urbanization and industrial development. Therefore, currently, Shenzhen is one of the leading economic hubs of China, an important gateway of the large Chinese economy, and a sub-provincial administrative centre in the PRD.
Sungang-Quingshuihe (SQ) is a neighbourhood of 2.5 square kilometres, in Louhu district in the east of Shenzhen. The landscape system of SQ has been largely destroyed and fragmented by developments. Our main goal is to redesign SQ neighbourhood for an innovative growth centre of Shenzhen. We envisage SQ as a liveable area with new and modern functions for international residents who work in higher education, information communication industry, medical services, R&D facilities of multinational corporations, and research-oriented start-up companies. In order to accomplish this vision it is required to design new transportation system, public buildings, housing, green corridors and parklands.
The present research is on the study of lycopene extraction from different raw and processed tomatoes, using traditional extraction methods with several solvents. The influences of the temperature and the light exposure were taken into consideration. The best extraction lycopene levels were obtained when chloroform:methanol mixture was used as solvent, followed by the hexane:acetone mixture and ethanol 95%. The lycopene is better extracted at room temperature compared with refrigeration and freezing temperatures. Lyophilized tomatoes contained the highest amount of lycopene (14.11 mg/100 g), followed by dried tomatoes with 6.01 mg/100 g, tomato juice with 11.38 mg/100 g, and the fresh tomatoes with 4.13 mg/100 g.
Authors:Valentin Pricop, Elena Helerea and Gheorghe Scutaru
In this paper a procedure for magnetic hysteresis measurement in quasi-static regime with a controlled rate of change of the magnetic polarization is proposed. The waveform of the polarization is modulated by means of iterative augmentation using an inverse approach. The setup, the measurement principle and the logical diagram of the procedure algorithm are presented. Experimental results obtained with the new procedure, applied on soft magnetic materials are presented. The measurements made at 0.1 Hz and 1 Hz show a difference of the characteristic values in the range of 5 % to 8 %. The paper demonstrates that, with this new procedure, quicker and more reliable measurements could be obtained.
Authors:B. Bhattacharjya, H. Dutta, K. Patwari and C.L. Mahanta
Jackfruit seed starch was annealed by single stage and double stage processes and characterised for changes in properties. Single-stage annealing gave higher crystalline order than double-stage annealed starch. No major change in the granular morphology was observed. Annealing resulted in notably altered pasting properties. Increased peak viscosity was indicative of molecular rigidity developed in the granules due to annealing. The increased thermal stability in DSC and specific peak sharpening in the XRD patterns of single-stage annealed starches indicated development of ‘site specific’ crystallinity. The new crystallites formed during the first stage of double-stage annealing were heat labile as crystallinity lowered after the second stage. Single stage annealed jackfruit seed starch can be used for noodle making.
Authors:Marian Holub, Magdalena Balintova and Eva Singovszka
The remains of human activities may be seen in several places of the landscape in positive or negative form. Probably the most common phenomenon that fundamentally impacts the country is mining activity. The environmental problems caused by mining have attracted a great deal of research attention and led to development of numerous sediment heavy metal contamination assessment methods, including the index method, the dynamic method, the synthesis methods in chemistry, ecology and toxicology, etc.
This research was undertaken in order to determine and analyze selected heavy metals present in sediment samples collected from different sampling localities inside and around water reservoir Ruzin, Slovakia. Reservoir and its inflows are located in the vicinity of region with historical Cu, Fe, Ag, Au-deposit, which was exploited from the 14th century to 1990 and currently causing environmental burden. For the determination of sediments quality different methods (XRD and XRF analysis) have been used.
Based on the obtained data of analysis, potential ecological risk indices were used to study the pollution status of heavy metals in sediments and assess their potential ecological risk to environment.
The calculated potential ecological risk indicates the level of water environment pollution by heavy metals in the sampling localities in the studied area.
The paper deduces general relationships of real analytical functions for 1D quasi steady-state harmonic model of a conductor plate pair. To demonstrate the use of the model, the results are applied to calculate the active and reactive power of an induction furnace with graphite crucible and to determine the eddy current loss in different shielding arrangements.
Authors:M.I. Piñon, A.D. Alarcon-Rojo, A.L. Renteria, G. Mendez and H. Janacua-Vidales
Marinated chicken meat is an ideal substrate for the growth of microorganisms. The aim of this study was to determine the effect of high-intensity ultrasound on the microbial flora of chicken meat marinated in oregano oil. Three concentrations of oregano oil (0%, 0.1%, and 0.3%) and two types of marination (traditional and highintensity ultrasound) were tested. Microorganisms were enumerated immediately after marination and on 7, 14, and 21 days of chilled storage. Marination in oregano oil resulted in significant differences (P<0.05) in the numbers of anaerobic, lactic acid bacteria, and mesophiles. Ultrasound with 0.1% OEO did not show any effect on the three types of bacteria. The treatment with 0.3% oregano oil and ultrasound had the greatest effect on controlling microbial growth. Therefore, a combination of ultrasound and oregano oil is the most appropriate option for reducing the growth of mesophilic, anaerobic, and lactic acid bacteria in vacuum-packed marinated chicken breasts during chilled storage.
Recently, it has become extremely important to reduce the heating energy demand and the CO2 emission of buildings. This reduction can easily be achieved by insulating the shell of buildings. By thermal insulation not only the heating energy demand can be reduced but also higher thermal efficiency can be reached. Therefore, measurements, calculations and simulations are carried out on the energy efficiency of buildings. Furthermore, the combination of methods is of great importance. Combination of experiments with building simulations solution can make design practices and sizing processes easier in the investigation of building performance. The purpose of this article is to demonstrate how the energy balance of a building can be changed in function of the wet building envelope in the Central European Region. A real and available building (old family house) was tested and it was placed (hypothetically) in three different countries (Austria, Hungary and Slovakia). In this study two types of load-bearing structures (brick and concrete) covered with four different types of insulations (mineral wool, expanded polystyrene, graphite-doped expanded polystyrene, and extruded polystyrene) were tested. The change in the heating energy of the building in three different countries by the function of measured water contents of the thermal insulators was simulated by CASAnova simulation software.
Authors:Cosmin Maris, Cristian Vulcu, Aurel Stratan and Dan Dubina
The current paper presents the outcomes of an extensive pre-test numerical investigation program carried out with the aim to validate the design procedure for bolted beamto- column connections with haunches. In the first part of the paper, a description is made with regard to the analytical procedure that was used for the design of full strength and rigid joints. The results from the pre-test numerical simulations are further presented for each beam-to-column joint assembly, in terms of overall response (moment-rotation curve, failure mechanism), as well as local response, particularly the behavior of joint components (stress distribution, plastic strain, force level in the preloaded bolts). Finite element simulations highlighted that plastic deformations occurred in the beam close to the end of the haunch. In addition, minor plastic deformations were observed in the bolts close to the beam flange in tension, and therefore also higher force levels compared to the computed design capacity. As a result, the design procedure was adjusted with the aim of keeping the non-dissipative components of the joints in the elastic range. Additional information is presented with regard to the position of the plastic hinge, the effect of preloaded bolts, the distribution of forces in bolt rows and the change of the lever arm due to the presence of the haunch in compression zone. The main conclusions of the study are finally presented.
The aim of this paper is to verify activity index (pozzolanic reactivity) of finegrained waste glass and clay brick. First part of this work consists from milling process with variation in milling parameters (time, grinding ratio) and determination (analysis) of the grain size distribution. Subsequently strength activity index is assessed for samples of particles size 50-60 μm. According to EN 450-1 method, tested samples does not reached an appropriate limit values as 25% substitute of cement. This result does not disqualify this type of construction and demolition waste as active additive in building materials but it is necessary improving their input parameters.
Authors:G. Šimić, A. Lalić, D. Horvat, I. Abičić and I. Beraković
β-Glucan content and β-glucanase activity of winter and spring barley cultivars grown under different environments were evaluated. There were significant differences in both β-glucan content and β-glucanase activity between analysed barleys. The results showed that, for all cultivars and locations, approximately 75% of β-glucan present in grains was degraded after malting, and that marked differences existed among winter and spring type of cultivars in malt β-glucan content. The correlation analysis of β-glucan content and malt quality parameters showed that malt β-glucan content was significantly positively correlated with viscosity and extract difference, and negatively with malt β-glucanase activity and friability. Regarding malt β-glucanase activity, significantly higher activity was found in spring cultivars in contrast to winter cultivars.
Authors:J. Cetkovská, P. Diviš, M. Vespalcová, J. Pořízka and V. Řezníček
The ascorbic acid, total polyphenols, total anthocyanins and mineral content, together with antioxidant activity, was determined in five Czech, two Ukrainian and two Austrian cultivars of cornelian cherry (Cornus mas L.) widely grown in the Czech Republic. Ascorbic acid content varied between 199–433 mg kg−1, total polyphenols between 2174–6143 mg kg−1, and total anthocyanins between 61–253 mg kg−1. All fruits were good sources of major metals (K, Ca, Mg, Fe, and Mn) and trace elements (Cu, Zn, and Cr). The antioxidant activity was determined by EPR and DPPH radical scavenging assay and ranged from 29.5% to 67.2%. There was a linear relationship between antioxidant activity and total polyphenol content. Based on the obtained results, Ekotišnovský, Fruchtal, and Ruzyňský cultivars were recommended for further investigation and breeding programme of cornelian cherry fruit in the Czech Republic.
Authors:J. Pokorná, P. R. Venskutonis, V. Kraujalyte, P. Kraujalis, P. Dvořák, B. Tremlová, V. Kopřiva and M. Ošťádalová
Coffee beans contain a large amount of antioxidants, which are subjected to various changes during roasting. In this study, antioxidant potential of raw and roasted to different degree (light, medium, dark) C. arabica and C. robusta coffee beans was evaluated by the four antioxidant assay methods, TPC, FRAP, TEAC, and DPPH˙.
The obtained results revealed significant differences between the coffee types, roasting degree, and antioxidant activity assessment methods. FRAP and TPC appeared to be the most appropriate methods for revealing the differences in antioxidant potential of different coffee types and the effects of roasting. The results obtained by these methods were in good correlation. ABTS and DPPH? methods are not enough sensitive for the determination of roasting degrees.
In general, based on statistical data evaluation, antioxidant activity is more dependent on the coffee type than on the degree of roasting, however, the selection of analytical method may also be significant.
Plants exposure to environmental sources of common inorganic anions (chloride, nitrate, phosphate, and sulphate) is discussed. Various commercial tea products were examined for the content of water soluble anions by the use of sample preparation procedure corresponding to the conditions generally applied for the preparation of tea infusions (2 g of tea, 5 min brewing time, 250 ml final volume) widely consumed by humans. Suppressed ion chromatography (IC) (Metrohm Metrosep A Supp 5 (150 mm × 4 mm) column) with conductometric detection was used for the determination. The IC technique allows isolation of the signals of particular anions and their detection (DLs of 0.012 (Cl−), 0.019 (NO3−), 0.047 (PO 43–), and 0.011 (SO 42–) mg l−1) within 15 min.
Authors:S. C. Tran, H. Th. Le and T. H. Thai-Nguyen
A modified QuEChERS method was developed and validated for determination of pesticide multi-residues in green tea by liquid chromatography tandem mass spectrometry. Lead acetate was first time used together with primary secondary amine and graphite carbon black to eliminate tannin, caffeine, and other pigments in tea and thus reduced the matrix effects. The method was compared to the original QuEChERS method as well as A.O.A.C. QuEChERS method. For accurate quantification, the matrix matched calibration technique was used. The method showed good performance in the concentration range from 0.01 to 1 mg kg–1. All pesticides could be quantified at and lower than 0.01 mg kg–1. Recoveries were from 70 to 120% and repeatabilities were <15% RSD depending on the compounds.
Authors:J. Bystricka, J. Musilova, J. Tomas, J. Noskovic, E. Dadákova and P. Kavalcova
Onion bulbs (Allium cepa L.) are good sources of flavonoids. The aim of this study was to analyse the changes in dynamics of quercetin formation in three varieties of onions (white, yellow, and red) during the vegetation period. Quercetin content was determined after acid hydrolysis (1.2 M HCl in 50% aqueous methanol) by high-performance liquid chromatography (HPLC). The content of total phenolics was determined using Folin-Ciocalteu reagent (FCR) according to LACHMAN and co-workers (2003). The content of polyphenols in onion ranged from 2893 to 6052 mg kg–1 and the content of quercetin ranged from 52.44 to 280.72 mg kg–1 in fresh matter. The highest content of polyphenols and quercetin was found in the red variety. According to statistical analysis the dynamic of quercetin formation in all cultivars had statistically moderate (P<0.05) increasing tendency. Increasing content of polyphenols was accompanied with slight increase of quercetin, but the differences remained insignificant (P<0.05).
Authors:J. Tangtua, C. Techapun, R. Pratanaphon, A. Kuntiya, V. Sanguanchaipaiwong, T. Chaiyaso, P. Hanmuangjai, P. Seesuriyachan, N. Leksawasdi and N. Leksawasdi
Candida tropicalis TISTR 5350 was used in the comparison of seven concentration levels of silver nanoparticles (0, 5, 10, 15, 20, 25, and 30 μg ml–1) for cell disruption methods. The optimized cell disruption strategy was selected based on the optimal protein yield and biological activity. The maximum volumetric and specific pyruvate decarboxylase (PDC, EC 184.108.40.206) activities (0.53±0.05 U ml–1 and 0.17±0.02 U mg–1 protein, respectively) were observed at 15 μg ml–1 silver nanoparticles. The silver nanoparticle concentration level of 15 μg ml–1 was investigated further by comparing the reaction mixtures at different time intervals of 0, 1, 2, 3, 4, 5, and 6 min. The result showed that the highest specific PDC activity of 0.39±0.01 U mg–1 protein was obtained from mixing for 3 min. This was not significantly different (P≤0.05) from other mixing time intervals.
Authors:B. K. Kim, H. M. Shahbaz, K. Akram, C. T. Kim, J. J. Ahn and J. H. Kwon
This study was aimed at evaluating the efficacy of different mineral separation procedures to validate the EN1788 (2001) European Union standard protocol for better identification of irradiated fish and shellfish. The silicate minerals were isolated with physical density separation method from two types of non-irradiated freeze-dried fish and shellfish that included Pacific saury (Cololabis saira), mackerel (Scomber japonicus), shrimp (Penaeidae metapenaeus), and mussel (Mytilus coruscus). Radiation-specific thermoluminescence (TL) peaks (glow curve 1) were observed between 150–250 °C. The peaks are typical for the irradiated food; despite the samples being not irradiated. Apparently it showed that the isolated minerals were contaminated with organic materials such as bone, etc. Acid-hydrolysis digestion was employed to remove the possible contaminants. The minerals obtained through alternative pre-treatment showed no TL curves in radiation specific temperature range. Moreover, acid hydrolysis extraction resulted in producing higher mineral yields and lower background luminescence. Results were also confirmed by calculating TL ratios (glow curve 1/glow curve 2) to confirm the irradiation history of samples. Furthermore, different time and temperature treatments on TL intensity of irradiated standard quartz (SiO2) minerals showed that the acid-hydrolysis can be adjusted to 50 °C and 3 h for better luminescence determinations.
Authors:K. Török, L. Hajas, Zs. Bugyi, G. Balázs and S. Tömösközi
Disorders induced by cereal proteins (e.g. wheat allergy, celiac disease) are widespread in human population. Since their only effective treatment is the avoidance of the problematic proteins, patients have to be familiar with the composition of food products. For checking special foods produced for them, proper analytical methods are necessary. At the moment, in gluten analysis there are no reference methods and reference materials which model real food matrices. During the production and experimental utilisation of our previously developed reference material candidate, numerous questions emerged. As our model product is a real food matrix, interactions can be present between gluten proteins and other macro and micro components. Fat content of the baked cookies is almost 20%, which might affect the results of ELISA measurements. The detectable gluten content is significantly increasing after the defatting procedure, as a pre-treatment of samples. Moreover, baking is a common food processing step that might modify the structure of gluten proteins leading to denaturation and aggregation. In the soluble protein fraction the amount of low molecular weight proteins increases, while that of high molecular weight proteins decreases during the baking procedure.
Authors:M. T. M. Montanhini and R. Montanhini Neto
Oysters are filter-feeding bivalve molluscs that are associated with several foodborne illnesses, because they accumulate biotic and abiotic contaminants dispersed in the water. The state of Paraná in southern Brazil is distinguished by a high consumption of oysters, typically eaten raw, and this habit may present a risk to consumer health if the product is contaminated with pathogenic bacteria. This study intends to evaluate the microbiological quality of oysters produced and traded in Paraná, directly examining the localities of cultivation and trading of the product. The major sites for the trading of oysters in the state were identified and 52 dozen oysters (624 animals) were collected from these places, between April and December, 2013. The samples were subjected to analyses for total coliforms, Escherichia coli, Staphylococcus aureus, and Salmonella spp. No samples had results of microbial contamination above the limits established by Brazilian legislation. This study indicated that the microbiological quality of the oysters produced and traded in the state of Paraná is acceptable.
Authors:J. A. Grahovac, Z. Z. Rončević, I. Ž. Tadijan, A. I. Jokić and J. M. Dodić
Bacillus subtilis is one of the most important producers of diverse antimicrobial compounds. This bacterium grows and produces antibiotics on different substrates. The increase of the antibiotics yield can be achieved by changing the conditions of cultivation and the composition of the culture media. In this study, response surface methodology was used for optimization of glycerol, sodium nitrite, and phosphate content in media for production of antibiotics effective against Staphylococcus aureus. As biosynthesis strain Bacillus subtilis ATCC 6633 was used. The developed model predicts that the maximum inhibition zone radius (38.08 mm) against Staphylococcus aureus and minimal amount of residual nutrients (glycerol 1.75 g l−1, nitrogen 0.21 g l−1, phosphorus 0.18 g l−1) are achieved, when the initial content of glycerol, sodium nitrite, and phosphate are 49.99 g l−1, 1.00 g l−1, and 5.00 g l−1, respectively.
The refinement of unsaturated fatty acids (UFA) from Hippophae rhamnoides L. seed oil was carried out by molecular distillation (MD) using response surface methodology (RSM). A central composite rotate design was used in order to optimize the experimental parameters: distilling temperature and feed flow. The optimal MD conditions were determined and the quadratic response surfaces were drawn from the mathematical models. The results suggested that the distilling temperature and feed flow significantly affected both the UFA content and oil yield in the two models. The optimum conditions for refining UFA were: distilling temperature 107.5 °C and feed flow 1 ml min−1. Optimal values predicted by RSM for the UFA content and oil yield were 82.38% and 62.59%, respectively. Close agreement between experimental and predicted values was obtained.
Authors:N. Topic Popovic, A. Benussi Skukan, P. Dzidara, I. Strunjak-Perovic, S. Kepec, J. Barisic and R. Coz-Rakovac
Listeria monocytogenes is a bacterium widespread in the environment, which has a capacity to survive and grow under various conditions. The bacterial growth results from interactions when subjected to various temperatures, pH levels, and NaCl concentrations were examined by measurements and predictive modelling. Good correlation across the range of growth conditions was shown among observed and predicted growth values, having similar trends and minimal deflections for pH levels 5.0 and 6.0. The growth condition in the 8% NaCl concentration (pH 7.0, temperature 4 °C) resulted with a growth curve of 1 log interval greater than the fitted curve for all the measurements. In all of the cases, there were consistent increases in the rates and decreases in the lag time when the growth temperature increased. Higher incubation temperatures provided higher growth rates as 30 °C and 35 °C yielded double increase of the fitted rate. Fitted and measured growth rates for salinity conditions were significantly different (P<0.05). Comparison of doubling times showed good compatibility, particularly at lower temperatures. Critical use of a model is suggested, although it may enable microbiologists to limit the need of challenge tests and to make rapid and realistic prediction of the growth of L. monocytogenes under conditions relevant to a range of aquatic and other products examined.
The ability of Kocuria varians to grow and produce protease when utilizing various local wastes was studied. Impact of cultivation pH on growth and enzyme production was also evaluated. Cassava waste combined with bambara nut waste (1:1) gave the best protease yield. Maximum enzyme production was attained when production medium was adjusted to pH 9. Highest protease concentration in the culture fluid was recorded at 20 h during the exponential phase of growth. The enzyme was optimally active and stable at 80 °C. Optimum pH for protease activity was at 11 with optimal stability at the alkaline range (pH 7–11) after incubation for 1 h. The enzyme was inhibited by EDTA, Hg2+, and Zn2+, but not by Pb2+, and was slightly stimulated by Cu2+. The properties of this protease make it a promising candidate for further studies and possible applications in processes involving extreme conditions of pH and temperature.
Authors:Zs. Hajdu, L. Lorántfy, N. Jedlinszki, K. Boros, J. Hohmann and D. Csupor
The radish-like hypocotyls of Maca (Lepidium meyenii Walp., Brassicaceae) are widely consumed as common vegetable in the Andean highlands. It is considered as healthy food, rich in carbohydrates and protein, a herbal medicine with a general invigorating reputation and fertility and sexual performance enhancer. The latter is the most popular contemporary application of the plant in Europe. The number and variety of industrial products on the market is increasing. Here we report the development of a simple and reliable analytical protocol for the qualitative and quantitative analysis of maca content of preparations and for the detection of synthetic phosphodiesterase inhibitors. Fourteen products were analysed by the method based on TLC and HPLC-DAD analysis developed by us. Our experiments revealed that beside good-quality products, the majority of the multicomponent preparations did not contain the declared herbal component or the quantity of the measured macamide was very low. Furthermore, one preparation is adulterated with a synthetic phosphodiesterase inhibitor. The presented method is suitable for quality control of L. meyenii products.
Authors:P. Chaikham, A. Apichartsrangkoon, S. Srisajjalertwaja and C. Phanchaisri
Alteration of physical and chemical qualities of pressurized and heat treated Nam Prig Nhum (Thai-green-chili paste) was thoroughly assessed upon storage for eight weeks. During storage, colour L, –a*, and b* parameters of pressurized Nam Prig Nhum displayed comparatively low changes. The enzyme activities of peroxidase, lipoxygenase, and polyphenol-oxidase nearly fell by half during storage. Peroxidase was the most resistant to pressure followed by lipoxygenase and polyphenol-oxidase. For pungent components, all capsaicinoids in Nam Prig Nhum underwent alteration by the thermal processes as well as by acidic and oxidative degradation during storage. However, higher amount of capsaicinoids were retained in pressurized than in heat treated products.
The HACCP system is a food safety approach, which prevents hazards before they happen. With this survey we aimed to determine the HACCP knowledge of staff working in kitchens of food businesses in Istanbul and correlate the results with some demographic characteristics in order to evaluate HACCP awareness in the foodservice sector in Istanbul. A self-administrable questionnaire was developed in order to evaluate the knowledge of food handlers in all stages of kitchen work. The questionnaire consisted of a first set of 9 demographic questions followed by 12 items related to HACCP system application. According to data obtained from this study, food handlers’ HACCP knowledge increases parallel with age, education level, and time spent in the sector and seniority. In addition, in order to increase the knowledge and awareness of HACCP, training has been found to be important.
This study aimed to evaluate the survivability of lactobacilli cells encapsulated in calcium alginate beads coated with methacrylic acid copolymers (MAc) in high acidic foods (orange juice and mayonnaise). Lactobacilli survived well at low temperature (4 °C) for 6 wk in orange juice, 4 wk in heat-treated orange juice, 12 wk in mayonnaise, and 8 wk in heat-treated mayonnaise (P<0.05), without affecting the acidity of orange juice and mayonnaise during storage. FTIR spectra showed that the characteristic peaks of calcium alginate and MAc were not altered, designating no high affinity interaction between calcium alginate and MAc. DSC of MAc-coated alginate beads indicated an increased in melting temperature, demonstrating improvement in molecular orientation in the MAc-coated alginate beads compared to the control. Sensory evaluation revealed that panellists could detect the presence of MAc-coated alginate beads, leading to a lower acceptance score.
The present study was designed to investigate the antioxidant and antimicrobial activities of pressurized liquid extracts from Haberlea rhodopensis Friv. The total phenolic content was performed using the Folin-Ciocalteu phenol reagent. To determine the antioxidant activities of the extracts, several complementary tests were used: ABTS and DPPH radical scavenging activities, oxygen radical absorbance capacity, and ferric-reducing antioxidant power assay. The phenolic concentration was 15.98±0.09 and 9.42±0.06 mg GAE g−1 DW for 70 and 85% ethanol extracts, respectively. Of all the performed methods, the highest antioxidant activity values were measured by the ORAC assay — 224.6±6.6 and 154.0±9.9 μM TE g−1 DW for 70 and 85% ethanol extracts, respectively. Results also showed that both extracts exhibited very weak antimicrobial activity against the examined microorganisms. However, the 70% ethanol extract possessed higher inhibition ability, which correlated with higher total phenolic content and antioxidant activity.
An integrated hydrological model has been applied for small rural-urban catchments at the Tisza-Maros confluence using the WateRisk integrated hydrological model system. The aim of the hydrological simulations was to identify the role that the relief plays in the runoff generation process, and to highlight the relationship between the precipitation, runoff and the depression’s water storage of the relief. The overall aim is to support the description of contaminant (phosphorus) transport processes with knowledge about the rainfall-runoff-storage relationship, described with the complex deterministic hydrodynamic model system. To support this aim the rainfall-runoff and the one-dimensional flow routing modules have been used in the model. Results suggest that the depletion of the surface depressions water storage capacity is a non-linear saturation type function of the amount of rainfall falling on the surface. Manning n values of the drainage channel system might also have strong influence on runoff dynamics.
Authors:Marina A. Razzhivina, Boris A. Yakimovich and Aleksandr I. Korshunov
The head-line of the article is advisability to combine information technologies and principles of lean production in activity of machine building enterprises to ensure efficiency improvement. The article reviews enterprise resource planning systems and the lean production conceptions: their development and construction basis, main advantages and weaknesses.
The topic of the paper is to investigate procedure to determine bending moment resistance of girders with corrugated webs. Concepts provided by Eurocode EN 1993-1-5 and EN 1999-1-1 are different and not very clear for practical design. To clarify determination of elastic critical bending moment, a finite element model of simply supported beam under uniform bending moment has been created. Positive influence of web corrugation on bending stiffness has been expressed through the improved factor c1 used for flat girders. Results of bending moment resistance have been compared to show the difference between the concepts and to provide more appropriate assessment.
The innovative suggestion of this work is the usage of bended composite arms instead of complicated steel arms with hinges. The basic idea of the new structure is very simple, which is one of the best advantages of this structure. The bended arms could pre-stress the membrane surface and in the same time the membrane bends the arms, this interaction produces a harmonic structure with effective properties. The hinges can be avoided, because the open position of the umbrella created by the bend of the arms. Nowadays existing retractable funnel umbrellas are highly advanced, which is a result of decades of development, but the openingclosing process is quite complicated with very complex kinematics and complicated steel structure. Using the bended supporting elements a new structure for the retractable funnel umbrellas could be developed, which provides better structural behavior and simpler motion during the opening-closing process. The goal of this work is a development of a new type of convertible umbrella with innovative structure, which opens up new perspectives concerning the design of umbrella structures. The benefit of the new structure compared to the existing umbrella structures is a much easier working principle, which allows leaving the complex moving elements and joints. The main advantage of this structure comes from its simplicity as it simplifies the operation of umbrellas, making it a cost-effective and sustainable option.
In the recent years the Author participated in two Intelligent Energy Europe projects, which aim was to deliver transport-sector energy savings by creating travel plans. During the development of the projects two local travel plans were worked out, one for the residential area of Győr-Ménfőcsanak, Hungary and one for the elementary educational institutions of Győr. In 2012 additional travel plans were developed, this time for other target groups, one for the universities of Győr, and another one for the employees of three public institutions. The main objective of these studies was to reduce the problems, caused by private car users and more over to promote sustainable mobility choices for target groups. The results of the projects showed, that travel plans are effective tools in order to solve mobility challenges in a sustainable way, but transportation infrastructure and services have strong effect on the success of travel plans.
Initiation of traffic calming measures is on the challenging agenda of most cities, which are in pursuit of creating livable urban areas. However, previous studies on this research pointed out that the knowledge of the strategic aspects of application of these restrictions is insufficient, which is blocking further progression. Therefore a comprehensive policy assessment framework has been proposed and developed, which is combining modern modeling tools with reliable, well-tried appraisal methods. This work is another milestone of this broader research and its aim is to elaborate the modeling part of the framework enabling and establishing further works. The objective of this paper is to give an overview on this process and the result of which is a land-use and transport interaction model. In addition, it is also intended to practically test the model on a hypothetical case and to demonstrate its suitability.
The paper presents results of exceptional experimentation, which focuses on the long-term loading of timber beams. The uniqueness of the research is given by real dimensions of samples and by the term of loading over one year. In the frame of investigation four currently often used timber girders had been investigated. The aim was to observe the time dependence of deflections over time. According to deflection curves the approximations for simulating the final deflection at the end of structure’s lifetime had been defined. The obtained creep coefficients were compared with the values listed in the valid standards.
Authors:Klára Machalická, Martina Eliášová and Michal Netušil
Thanks to intensive research in the field of polymer adhesives in the last few years, there is a possibility of using a glued joint with a real load bearing role. The reliability of adhesive in the connection during the lifetime of a structure is affected by many factors, but the initial choice of a proper adhesive material is the most crucial one. The article deals with the experimental analysis focused on the determination of material characteristics of adhesives in planar connections, it describes the effect of various factors on the behavior of an adhesive joint under increasing loads, its ultimate bearing capacity and its failure modes. The main investigated factors are the type of adhesive, the type of connected materials (material of substrate), surface treatment and the thickness of the adhesive layer. A special part of the article describes numerical models of a glued joint with respect to different types of adhesive.
Authors:Ildiko Jancskar, Zoltan Sári, Adam Schiffer and Geza Várady
The paper suggests a design procedure for fuzzy cascade control. The expert knowledge based tuning procedure is supported by investigation the phase plane of the reference tracking. The plant is a one degree of freedom helicopter model with highly non-linear dynamics in a hardware-in-the-loop arrangement. Starting from a common fuzzy-PI controller in the outer loop and classic PI-controller in the inner loop, the presented tuning procedure enables to obtain fuzzy-adaptive parameter settings of the inner-loop and a heuristic modified rule base in the outer loop. The developed control strategy proves to be very successful: both the settling times and overshoots have become well regulated.
Authors:Lenka Angelovičová, Zuzana Boguská and Danica Fazekašová
Mining and processing activities in the former mining Middle Spis area caused serious environmental problems. The aim of the study is to determine the content of heavy metals (Cu, As, Pb, Fe, Hg) in water and describe the flora diversity along the Rudnansky creek, which flows through the area. Chemical (pH) and physical (water conductivity, oxygen saturation) water properties were also evaluated. High values of copper and mercury were determined at the localities close to the tailing pond and mercury processing plant. Presence of plant species resistant to heavy metals, such as Calamagrostis epigejos, Arctium lappa, Cirsium rivulare, Geranium palustre, indicates toxic element pollution.
The mining industry located in the Mecsek Hills has played a decisive role in the life of Pécs, which developed into an industrial settlement in the 19th century. Although the extraction of raw materials was discontinued in the last Pécs mine in 2004, the mining industry as a mental and built heritage still remains. Smaller estates, characteristic colonies of the early years of mining, have been significantly re-evaluated. The parts of the city built near the previous workplaces, far from the center, serve as the residence of people with the lowest income. The majority of approximately 4 000 municipal rental-housing units belong to this type of environment. Therefore, the future of the former mining colonies is crucial for the local government.
Authors:Sari Piippo, Paula Saavalainen, Juhani Kaakinen and Eva Pongrácz
Municipal solid waste management is a basic service that, in Finland, consists of collection, transportation and treatment systems provided by municipalities, waste management companies and producer responsibility organizations. The amount of municipal solid waste in Finland has risen quite steadily for many decades. In 2012, the recovery rate of municipal solid waste as material or energy was 67%. The Finnish Waste Act has been updated in 2012, with the key goal to further reduce waste amounts and progress recycling. The paper describes the best practices in strategic waste management planning and describes the organization of municipal solid waste in city of Oulu, Finland.
Authors:Eva Pongrácz, Johanna Niemistö, Verónica García, Niko Hänninen, Paula Saavalainen and Riitta Keiski
Further to Directive 2009/28/EC on the promotion of the use of energy from renewable sources, the share of biofuels in transport should rise to a minimum of 10% in Member States by 2020. In Finland, the goal is set at 20%, and it is estimated that this can be produced entirely in domestic factories, as long as the projects already underway will be successful and additional industrial-scale biofuel plants would be built. The paper reviews the state of projects underway in Finland, and outlines current research activity in promoting waste and by-product — based biofuels.
The effect of emergent aquatic canopy on over-lake wind field was investigated through detailed field measurements. The aerodynamic roughness length above reed canopy and above open water was determined from eddy-covariance data. It was found that the aerodynamic roughness length at short fetches could be more sufficiently estimated from wave age relations than from the logarithmical profile formula, indicating that near the canopy wind profile might deviate from the theoretical logarithmical form. The presented calculations lead to an improved understanding of the wind profile realignment and wind shear stress development at the interface of the characteristic lake zones, also enhancing the accuracy of the modeling of various wind-induced processes.
The world’s energy consumption continues to increase, which results in demographic changes, living standard increases and technical development. In the world and Hungary the interest in biomass crops also has increased considerably over the previous decades. This paper summarizes the most important biological, biotechnological and agronomical researches and results of our working group, in Department of Agricultural Botany, Plant Physiology and Plant Biotechnology, University of Debrecen. It represents our research group publications and introduces some efficient propagation possibilities of promising new perennial bioenergy crops, giant reed (Arundo donax L.) and Virginia fanpetals (Sida hermaphrodita Rushby).
Based on the general mathematical model of Dudás [3, 4] — which is appropriate for mathematical modelling of production technology methods and various toothed gear pairs — we have generated mathematical models which are appropriate for determination of tooth surface points of face gear and worm gear connection with conical and cylindrical worm by numerical way. After doing the necessary calculations, the CAD models of the worm gear drives could be generated. Based on these there is an opportunity for rapid prototyping (RP) technology for other connection and production geometric analysis.
For the verification of our calculated results, we generate CAD models of one to one given geometric conical and cylindrical worm gear drives for other analysis.
Authors:F.J. García-Alonso, I. Navarro-González, G. Ros and M.J. Periago
The aim of this research was to assess the total antioxidant activity (TAA) of lipophilic (Lextr) and hydrophilic (Hextr) tomato extracts using in vitro chemical tests and cell-based assays, focusing on possible synergistic actions between tomato antioxidants. Both Hextr and Lextr were HPLC analysed for their carotenoids, phenolic compounds, and ascorbic acid contents. For the evaluation of TAA, extracts were assayed alone or in combination using in vitro chemical tests (TEAC, FRAP) and cell-based (CAA) assays using human hepatoma (HepG2) and human histiocytic lymphoma (U937) cells. The only carotenoid detected in Lextr was lycopene, while a mixture of phenolic compounds (chlorogenic acid, caffeic acid, and rutin) was identified in Hextr. Ascorbic acid was not found either in Hextr or in Lextr. Upon extract combination (1:1, v/v), the FRAP assay revealed additive action between Lextr and Hextr, whilst a slight synergistic action was observed in TAA as measured by the TEAC assay. Synergistic action was better revealed when TAA was analysed using either U937 or HepG2 cells. This could be explained by the presence of a multiphase media (cell membrane and extra- and intracellular media) that might facilitate the distribution and interaction of antioxidants with different polarities and different mechanisms of action.
Caffeine is a bitter, white crystalline xanthine alkaloid that is synthesized in different parts of more than 60 plant species. In a previous study, caffeine content of 377 food samples obtained from the Hungarian market was measured by a validated HPLC technique. These analytical data were built up into a food composition database called NutriComp. Dietary caffeine intake of the Hungarian population was estimated based on the data of the National Nutritional Status Survey 2009. Daily caffeine intake of Hungarian adult males and females were 147±6.2 mg per capita (95% CI: 135–160), and 138±4.2 mg per capita (95% CI: 129–147), respectively. There was no significant difference between genders. The oldest men and women consumed significantly less caffeine than the people between 35–64 years of age. The main sources of caffeine are coffee and tea with 58–59%, and 35–37% of the total intake in men and women, respectively.
Authors:M.B. Mansour, R. Balti, D. Boujnah and M. Guerfel
The main goal of this study was to investigate the effects of moderate saline water irrigation on the composition and quality of olive oil of the “Chemlali” olive cultivar in comparison to a control plot grown under rain-fed conditions from two methods of olive tree propagation (suckers and cuttings). The antioxidant compounds, oxidative stability and volatile compounds of virgin olive oil samples were determined and reported. The irrigation did not affect free acidity and peroxide value