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Static mixer is used for premixing action before the main mixing process, for significant reduction of mixing time and energy consumption. In this article, the novel numerical approach called Discrete Element Method is used for modeling of granular flow in multiple static mixer applications, while the Computational Fluid Dynamic method was chosen for fluid flow modeling. The main aim of this article is to predict the behaviour of granules being gravitationally transported in different mixer configuration and to choose the best configuration of the mixer taking into account the total particle path, the number of mixing elements and the quality of the obtained mixture. The results of the numerical simulations in the static mixers were compared to experimental results, the mixing quality is examined by relative standard deviation criterion. The effects of the mixer type and the number of mixing elements on mixing process were studied using analysis of variance (ANOVA).

The mixing process greatly influence the mixing efficiency, as well as the quality and the price of the intermediate and/or the final product. Static mixer is used for premixing action before the main mixing process, for significant reduction of mixing time and energy consumption. This type of premixing action is not investigated in detail in the open literature. In this article, the novel numerical approach called Discrete Element Method is used for modelling of granular flow in multiple static mixer applications (1 - 3 Komax or Ross mixing elements were utilized), while the Computational Fluid Dynamic method was chosen for fluid flow modelling, using the Eulerian multiphase model. The main aim of this article is to predict the behaviour of granules being gravitationally transported in different mixer configuration and to choose the best configuration of the mixer taking into account the total particle path, the number of mixing elements and the quality of the obtained mixture. The results of the numerical simulations in the static mixers were compared to experimental results, the mixing quality is examined by RSD (relative standard deviation) criterion, and the effects on the mixer type and the number of mixing elements on mixing process were studied. The effects of the mixer type and the number of mixing elements on mixing process were studied using analysis of variance (ANOVA). Mathematical modelling is used for optimization of number of Ross and Komax segments in mixer in order to gain desirable mixing results. [Projekat Ministarstva nauke Republike Srbije, br. TR31055]

This article investigates the effect of processing parameters (conditioning temperature and binder content), on final quality of produced agro-pellets for heat energy generation, obtained from four different olive cultivars using different technological parameters. Technological, physical and chemical properties of pellets (carbon, hydrogen, nitrogen and sulphur content, particle density, abrasion length, moisture, ash content, higher and lower heating values, fixed carbon and volatile matter content) have been determined to assess their quality. The performance of Artificial Neural Network (ANN) was compared with the performance of second order polynomial (SOP) model, as well as with the obtained experimental data in order to develop rapid and accurate mathematical model for prediction of final quality parameters of agro-pellets. SOP model showed high coefficients of determination (r2), between 0.692 and 0.955, while ANN model showed high prediction accuracy with r2 between 0.544 and 0.994. [Projekat Ministarstva nauke Republike Srbije, br. III 46005 i br. TR-31055]

Two mechanical extraction techniques were used for the extraction of environmentaly interesting elements from coal fly ash: shaking, in which the extraction process lasted from 6 to 24 hours, and ultrasonic sonication during 15 to 60 minutes, with water as extractant. The concentration of anions in fly ash extracts were determined by ion chromatography, while atomic absorption spectrometry was used for determination of: As, Pb, Cd, Ni, Cr, Zn, Cu, Fe, Mn and Al. The ultrasonic sonication yielded slightly higher amounts of extracted anions and Pb, Al, Mn and Fe, while shaking-assisted extraction was more efficient for the Cr, As, Zn and Ni ions. The changes in pH value, particle size distribution in colloid, zeta potential and conductivity during ultrasound-assisted extraction were measured in order to explain changes on the surface of fly ash particles in contact with water and different processes (adsorption, ion exchange, flocculation) that occur in environmental conditions. Principal Component Analysis were used for assessing the effect of observed process parameters. Essential from a practical point of view is a quantitative evaluation of these elements leachable from coal fly ash to surface waters in environmental conditions and contamination of the environment. [Projekat Ministarstva nauke Republike Srbije, br. 172030, br. III45012 i br. III43009]

According to the modern nutritionist opinions, cereal products such as flakes and snacks are the most common foods in the daily diet. Extrusion technology makes it possible to apply different sources of ingredients for the enrichment of cereal-based flakes or snack products. Substances with strong antioxidant properties such as wild oregano have a positive impact on human health. Therefore, they attract the attention of scientists, consumers and food industry experts. This paper investigates the effects of the simultaneous addition of dry residue from wild oregano distillation (0.5 g / 100g of sample and 1 g / 100g of sample), on the physical-textural and color properties of corn flakes in order to create a new product with improved nutritional properties. The addition of dry residue of wild oregano positively influenced physical characteristics (decreased bulk density 30.2 %, increased expansion rate 44.9 %), as well as texture hardness and the work of compression, 38.1 % and 40.3 %, respectively. Also, oregano significantly changed the color of flakes. Tukey’s HSD test showed statistically significant differences between most of the mean values of physical-textural, color and sensory attributes in the oregano-added corn flakes compared to the control sample. Principal component analysis has been applied to classify the samples according to differences in the studied parameters. The data pointed out that investigated corn flakes with the addition of wild oregano are new food products with good physical-textural and sensory properties due to a higher level of antioxidant activity. Moreover, it may contribute to the valorization of edible industrial waste in food production. [Projekat Ministarstva nauke Republike Srbije, br. III 46005 i br. TR 31027]

The aim of this work was to evaluate the simultaneous effect of glycerol (30%, 40%, 50%) and guar-xanthan gum addition (0.1%, 0.3%, 0.5%) effect on starch based edible film mechanical and barrier properties. According to Response Surface Methodology, the most influential parameter in the second order polynomial models calculation was the percentage of glycerol, while the linear term of guar-xanthan content was important only for second order polynomial model calculation for tensile strength and water vapor permeability. According to Principal Component Analysis, samples grouping along the first component are primarily due to the content of glycerol, which is also confirmed by ANOVA analysis. According Cluster Analysis, two separate clusters are observed on the dendrogram, which includes the right (with the increased value of tensile strength) and the left cluster (with the increased value of elongation break and water vapor permeability). The observed distance the two clusters is considerable (approx. 80). [Projekat Ministarstva nauke Republike Srbije, br. TR-31055: Osmotic dehydration of food - energy and environmental aspects of sustainable production]

In the production bread wheat bran is used as a raw material rich in dietary fiber. Therefore, it is necessary to monitor the content of essential and toxic elements in the flour and bran. This paper investigates essential (Zn, Cu, Fe and Mn) and toxic (Pb, Cd, Hg and As) elements in products of milling wheat grown in the whole territory of Banat, the region in Serbia. Inductively Coupled Plasma Mass Spectrometry was used for analysis. The mean contents of the following elements Pb, Cd, Hg, As, Fe, Mn and Zn in wheat kernels were 0.143 mg/kg, 0.007 mg/kg, 0.017 mg/kg, 35.7643 mg/kg, 50.865 mg/kg, and 21.174 mg/kg, respectively. Cluster Analysis (CA) and Principal component analysis (PCA) was applied to discriminate and to group the different samples, according to element content. Quality results show that the first two principal components, accounting for 80.17% of the total variance, can be considered sufficient for data representation and the first two principal components of toxic elements and essential microelements. Cd (15.28%), Zn (17.91%), Cu (17.08), Fe (16.91%) and Mn (17.54%), have been found the most influential for the first factor coordinate calculation, while the contribution of Pb (27.93%) and Hg (61.86%) has been the most important variable for the second factor coordinate calculation. [Projekat Ministarstva nauke Republike Srbije, TRI 46005]

Thermal analysis of osmotically treated fish (Carassius gibelio) meat was performed by three thermal techniques: Differential Scanning Calorimetry (DSC) Modulated Differential Scanning Calorimetry (MDSC) and Thermogravimetry (TGA). The objective of the study was to investigate the effects of osmotic solutions (sugar beet molasses and aqueous ternary solutions) on the thermal characteristics of osmotically dehydrated fish meat (Carassius gibelio). The DSC thermograms of all samples assayed in this work, showed the characteristic glass transition, the protein denaturation endotherm in the range of 40 °C-90 °C and no water melting peak, as a consequence of characteristic behavior of samples with high non freezable water content. The results obtained suggest the existence of different thermal characteristics depending on osmotic solutions used in process of osmotic dehydration. Those changes of thermal characteristics involve differences in overall thermal stability, protein stability, and differences in glass transition temperature (Tg).

The aim of this study was to investigate starch and starch based edible films with and without oregano essential oil addition in terms of crystallinity by using X-ray diffractometry. Starch crystallinity is related to amylopectin linear chains which may give different X-ray diffraction patterns, described as A, B and C chains. Diffraction pattern of starch based edible film without essential oil addition showed broad diffraction peak in 15-20° 2θ region, indicating destruction of A-type crystal structure due to experimental conditions of casting procedure used in this work. Diffraction peaks of samples with 0.5 %, 1 % and 2 % oregano essential oil, whose shapes are to some extent retained after oregano oil addition, were centered at 20.8°, 20.1° and 21.6° 2θ respectively, while pattern of sample with 2% oregano essential oil showed additional diffraction peaks at 31.1°, 35.1°, 38.3°, 44.5° and 64.9° 2θ. X-ray diffraction patterns showed polymorphous nature of investigated starch samples with essential oils addition.

Studies were conducted to evaluate and compare the kinetic parameters related to the oxidation process of blackberry and raspberry seed oils in non-isothermal conditions by DSC. For that purpose, the oil samples were heated at six different heating rates, β (2, 5, 7.5, 10, 15, 20°C/min), starting from 40°C to the beginning of the oxidation process, under an oxygen flow of 50 ml/min. Experiments were performed using TA Instruments DSC Q1000, Differential Scanning Calorimeter (Delaware, USA). Kinetic parameters (activation energy, Ea (J/mol) andpre-exponential factor, A (min-1)) were calculated using isoconversional Ozawa-Flynn- Wall (OFW) method. Using the values of Ea and A the oxidation rate constant was calculated at 25°C and 120°C by Arrhenius equation. The oxidation rate constants of raspberry seed oil was about 2 times higher than that of blackberry seed oil, which indicates that blackberry seed oil is more stable in terms of oxidation.

The aim of this study was to investigate effects of osmotic treatment on microbiological profile and water activity (aw) in celery leaves and root, in order to indicate the usefulness of this drying technique. Samples of celery leaves and root were dehydrated in sugar beet molasses and aqueous solution of sodium chloride and sucrose, at three different temperatures. aw values of processed celery leaves and root were determined and the change of the microbiological profile between the dehydrated celery leaves and root was examined. The process of osmotic treatment improve the initial microbiological profile due to increasing dry matter content and lowering aw value of the all processed celery samples. Better microbiological load reduction was observed in samples of leaves compared with samples of roots. Measuring results were fitted to mathematical models using Response Surface Methodology and statistically evaluated using analysis of variance.

The presented paper describes an investigation of nettle leaves kinetics during osmotic treatment in two different osmotic solutions (sugar beet molasses and ternary solution, was made from sucrose in quantity of 1,200 g/kg water, NaCl in quantity of 350 g/kg water and distilled water), at temperature of 20, 35 and 50ºC, during 90 min process. The main objective of this study was to examine the influence of type of different osmotic agents, process temperature and immersion time on the mass transfer phenomena during osmotic treatment, as well as the antioxidant activity. Water loss and solid gain were monitored. Antioxidant activity of osmotically treated nettle leaves was measured using a novel assay based on decrease of DC polarographic anodic current of hydroxo-perhydroxo mercury (II) complex [Hg(O2H)(OH)] (HPMC) formed in alkaline solution of H2O2 at potential of mercury oxidation. In order to get an insight into agreement between HPMC assay and common spectrophotometric assay, DPPH (2.2- diphenyl-1-picrylhydrazyl) analysis has been included in this study. Strict correlation between HPMC with commonly used DPPH assay was observed.

Energy value of diets has importance for feed producers and farmers. Methods for in vivo determination of metabolisable energy have high accuracy, but they are time and cost consuming. The aim of this study was to investigate the effect of enzymatic digestible organic matter and values of proximate chemical analysis on prediction of the nitrogen corrected true metabolisable energy (TMEn) of diets for broilers. The performance of Artificial Neural Network was compared with the performance of first order polynomial model, as well as with experimental data in order to develop rapid and accurate method for prediction of TMEn content. Analysis of variance and post-hoc Tukey's HSD test at 95% confidence limit have been calculated to show significant differences between different samples. Response Surface Method has been applied for evaluation of TMEn. First order polynomial model showed high coefficients of determination (r2 = 0.859). Artificial Neural Network model also showed high prediction accuracy (r2 = 0.992). Principal Component Analysis was successfully used in prediction of TMEn.

Spelt wheat growing without use of pesticides is a suitable raw material for whole meal products. The aim of this study was to enhance the fiber content in spelt pasta by adding inulin HPX. Inulin HPX replaced the spelt farina in the quantity of 0%, 5%, 10% and 20%, thus contributing to a decrease in the toughness, and improving color of the pasta. The presence of inulin can be clearly distinguished from other polysaccharides components by 13C MAS NMR spectroscopy. A simultaneous increase in the area of the peaks at 81, 74, 64 and 58 ppm, obtained during the deconvolution analysis of the NMR spectra, is directly associated with the increase in the inulin content. Inulin contributes positively to the nutritive and technological characteristics of the pasta. Spelt pasta with 20 % of inulin is a new functional product with modified nutritional properties and with decreased digestible carbohydrates in the amuount of 43.2% and reduced energy of 27.2%. [Projekat Ministarstva nauke Republike Srbije, br. III 46005 i br. TR 31029]

The research was conducted with the aim of examining the presence of toxic elements (Pb, Cd, As and Hg) and essential elements (Zn, Cu, Fe and Mn) in selected samples of wheat flour and bran by Inductively Coupled Plasma Mass Spectrometry. The principal component analysis has been used for assessing the variety of samples. Quality results show that the first two principal components, accounting for 84.22% of the total variability, can be considered sufficient for data representation and the first two principal components for toxic elements and essential microelements. Zn (16.38%), Mn (16.19%), Cu (15.73), Fe (15.44%) and Cd (14.99%) have been found the most influential for the first factor coordinate calculation, while the contribution of Hg (89.09%) has been the most important variable for the second factor coordinate calculation. [Projekat Ministarstva nauke Republike Srbije, br. TR 31055]

Effective diffusivities of water, sucrose and minerals in osmotic treatment of pork cubes (M. triceps brachii) were calculated using Response Surface Methodology (RSM), with respect to temperature (20, 35 and 50oC) and concentration of sugar beet molasses, (60, 70 and 80% w/w). The numerical solution of Fick's' law for unsteady-state mass transfer in a perfect cube configuration was used to calculate the effective diffusivities of water, sucrose and minerals (Na, K, Ca and Mg). Zugarramurdi and Lupin's model was used to predict the equilibrium condition, which was shown to be appropriate for water loss and solute uptake during osmotic treatment. Effective diffusivity of water was found to be in the range of 6.95×10-10 - 8.03×10-10 m2s-1, the sucrose effective diffusivity was between 6.39×10-10 and 8.25×10-10 m2s-1, while diffusivities for minerals were in the range 6.34×10-10 - 8.82×10-10 m2s-1, for Na, 6.27×10-10 - 7.43×10-10 m2s-1, for K, 6.44×10-10 - 8.94×10-10 m2s-1, for Ca and 3.47×10-10 - 5.66×10-10 m2s-1, for Mg. [Projekat Ministarstva nauke Republike Srbije, br. TR 31055]

Screw conveyors are used extensively in food, plastics, mineral processing, agriculture and processing industries for elevating and/or transporting bulk materials over short to medium distances. Despite their apparent simplicity in design, the transportation action is very complex for design and constructors have tended to rely heavily on empirical performance data. Screw conveyor performance is affected by its operating conditions (such as: the rotational speed of the screw, the inclination of the screw conveyor, and its volumetric fill level). In this paper, horizontal, several single-pitch screw conveyors with some geometry variations in screw blade was investigated for mixing action during transport, using Discrete Element Method (DEM). The influence of geometry modifications on the performance of screw conveyor was examined, different screw designs were compared, and the effects of geometrical variations on mixing performances during transport were explored. During the transport, the particle tumbles down from the top of the helix to the next free surface and that segment of the path was used for auxiliary mixing action. The particle path is dramatically increased with the addition of three complementary helices oriented in the same direction as screw blades (1458.2 mm compared to 397.6 mm in case of single flight screw conveyor) Transport route enlarges to 1764.4 mm, when installing helices oriented in the opposite direction from screw blades. By addition of straight line blade to single flight screw conveyor, the longest particle path is being reached: 2061.6 mm [Projekat Ministarstva nauke Republike Srbije, br. TR-31055]

The purpose of this study was to investigate the adsorption properties of locally available lignocelluloses biomaterials as biosorbents for the removal of copper ions from aqueous solution. Materials are generated from juice production (apricot stones) and from the corn milling process (corn cob). Such solid wastes have little or no economic value and very often present a disposal problem. Using batch adsorption techniques the effects of initial Cu(II) ions concentration (Ci), amount of biomass (m) and volume of metal solution (V), on biosorption efficiency and capacity were studied for both materials, without any pre-treatments. The optimal parameters for both biosorbents were selected depending on a highest sorption capability of biosorbent, in removal of Cu(II). Experimental data were compared with second order polynomial regression models (SOPs) and artificial neural networks (ANNs). SOPs showed acceptable coefficients of determination (0.842 - 0.997), while ANNs performed high prediction accuracy (0.980-0.986) in comparison to experimental results. [Projekat Ministarstva nauke Republike Srbije, br. TR 31003, TR 31055]

Three pectin preparations were isolated from fresh sugar beet pulp during the 150 minutes of extraction, at pH values of 1, 3.5 and 8.5. CaSO4 precipitant was added to 100 cm3 of 0.1% (wt) solution of pectin. Studies were performed with 9 different concentrations of CaSO4 solution (50-450 mg dm-3) with the addition of a cationic polyelectrolyte (cationic PAM) in concentrations of 3 and 5 mg dm-3. The efficiency of pectin precipitation was monitored by measuring the zeta potential of pectin preparations. Optimal amounts of precipitant CaSO4, without the use of a cationic polyelectrolyte, were as follows: 490-678 mg CaSO4/g pectin. After the use of a cationic polyelectrolyte, the optimal amounts of CaSO4 were smaller (353-512 mg/g pectin). These quantities are significantly lower than the average amount of CaO used in the conventional clarification process of sugar beet juice (about 9 g/g pectin of sugar beet juice). [Projekat Ministarstva nauke Republike Srbije, br. TR -31055]

This paper deals with the characteristics of spelt pasta enriched with eggs. Eggs were added to spelt farina in the quantity of 0, 124 or 248 g/kg (equivalent to 0, 3 or 6 eggs, respectively). Post-hoc Tukey’s HSD test at 95% confidence limit showed significant differences between various samples. Relatively low coefficients of variation have been obtained for each applied assay (1.25-12.42%), which confirmed the high accuracy measurements and statistically significant results. Standard score analysis is applied for accessing the contribution of eggs content to spelt pasta quality. Maximum scores regarding quality (0.89) and chemical characteristics (0.70), have been obtained for 6 eggs spelt pasta formulation. It is also shown that the presence of eggs in pasta can be clearly confirmed by 13C MAS NMR spectroscopy. Simultaneous increase in area of peak positioned at 29.5 and 176 ppm is directly associated with the increase in the content of added eggs in the corresponding samples. Pertinent data point at positive contribution of eggs to the spelt pasta and also that NMR spectrum can be used in the egg quantity control. [Projekat Ministarstva nauke Republike Srbije, br. TRI 46005 i br. TR 31029]

The aim of this work was to study the changes in osmotically treated pork meat during rehydration. Meat samples were osmotically treated in sugar beet molasses solution, at temperature of (23±2)°C for 5 hours. After being osmotically treated, meat samples were rehydrated at constant temperature (20- 40°C) during different times (15-60 min) in distilled water. The effective diffusivity were between 8.35 and 9.11•10-10 (m2•s-1) for moisture, 6.30-6.94 • 10-10 (m2•s-1), for Na, 5.73-7.46 10-10 (m2•s-1), for K, 4.43-6.25 • 10-10 (m2•s-1), for Ca, 5.35-6.25 • 10-10 (m2•s-1), for Mg, 4.67-6.78 10-10 (m2•s-1), for Cu, 4.68-5.33 • 10-10 (m2•s-1), for Fe, 4.21-5.04 • 10-10 (m2•s-1), for Zn and 5.44-7.16 10-10 (m2•s-1), for Mn. Zugarramurdi and Lupin’s model was used to predict the equilibrium condition, which was shown to be appropriate for moisture uptake and solute loss during rehydration. [Projekat Ministarstva nauke Republike Srbije, br. TR-31055: Osmotic dehydration of food - energy and environmental aspects of sustainable production]

Osmotic dehydration is a low-energy process since water removal from the raw material is without phase change. The goal of this research is to estimate energy efficiency of the process of osmotic dehydration of pork meat at three different process temperatures, in three different osmotic solutions and in co- and counter-current processes. In order to calculate energy efficiency of the process of osmotic dehydration, convective drying was used as a base process for comparison. Levels of the saved heat energy in the process of osmotic dehydration in comparison to convective drying were from 1.40 MJ to 1.97 MJ per 1 kg of fresh meat. Based on the presented results it can be concluded that the optimization of the process of osmotic dehydration from the aspect of energy efficiency has to include: choosing molasses as an osmotic solution; process temperature of 20°C; choosing counter-current process due to higher energy efficiency.

Single pitch screw conveyors are commonly used equipment in industry, used for transport of bulk materials. In this paper, several horizontal single-pitch screw conveyors with modifications in helices geometry were investigated for mixing action during transport, using Discrete Element Method. The influence of geometry variations on the performance of screw conveyor was examined, different designs were compared, and their effects on mixing performances were investigated. During the transport, the particle tumbles down from the top of the helix to the next free surface and that segment of the path was used for auxiliary mixing action. According to results, the addition of three complementary helices or blades, oriented in the same, or the opposite direction of screw helix, enlarges the particle path within the screw conveyor 3 - 5 times.

The main goal in this work was to investigate the structure of starch based edible films with essential oil addition. Films were obtained from water solution containing starch, polyol, guar-xantan gum modified mixture and essential oil by casting it on a Petri dish. Black cumin essential oil was added in three different concentrations. Starch based edible film without essential oil was used as a control. Physical, mechanical and structural properties are determined: thickness, tensile strength, elongation at break and film structure. FTIR results pointed to quantitative law dependency between amount of essential oil and spectra absorption values. Based on dependency coefficient of correlation was calculated (R2=0.99483).

The main objective of this article was to investigate the use of the diffusive model, Zugarramurdi and Lupin's model, Peleg's model, second order polynomial model and Weibull-type model for the prediction of water loss and solid gain, during osmotic treatment of fish (Carassius gibelio) in sugar beet molasses solution. The accepted experimental design allowed to assess the effect of solution concentration (60-80% w/w), temperature (10, 20, 35 and 50oC) and immersion time (1-5h), and to quantify water and solid mass transfer coefficients. The considered empirical models were able to represent satisfactorily the transfers of water and solids during all osmotic treatments.

Osmotic treatment of the fish Carassius gibelio was studied in two osmotic solutions: ternary aqueous solution - S1, and sugar beet molasses - S2, at three solution temperatures of 10, 20 and 30oC, at atmospheric pressure. The aim was to examine the influence of type and concentration of the used hypertonic agent, temperature and immersion time on the water loss, solid gain, dry mater content, aw and content of minerals (Na, K, Ca and Mg). S2 solution has proven to be the best option according to all output variables.[ Projekat Ministarstva nauke Republike Srbije, br. TR 31055]

This paper investigates the convenience of different chemical and rheological methods for determining the quality of two spelt cultivars for pasta making and the influence of egg quantity on whole meal pasta quality. Post-hoc Tukey’s HSD test at 95% confidence limit has been calculated to show significant differences between different samples. Score analysis is being useful tool for accessing the effect of eggs to spelt pasta quality, and this analysis proved that though lower scores (0.270) for rheological characteristics experienced with cultivar Eco, the addition of eggs is positively contributing to the spelt pasta quality yielding the best score for pasta (0.75), contrary to the cultivar Austria attributed with superior rheology scores. Whole meal spelt is characterised by lower Ca, but higher Fe and Mn content in comparison to bread wheat. In comparison with common pasta, spelt is a suitable raw material for a new product with improved functional properties at the market.[Projekat Ministarstva nauke Republike Srbije, br. TRI 46005 i br. TR 31055]

This paper presents the effects of different process temperature (20, 35 and 50 °C), immersion time (1, 3 and 5 hours) and the concentration of sugar beet molasses + NaCl + sucrose water solution on osmotic dehydration of pork meat (M. triceps brachii) cubes, shaped 1 x 1 x 1 cm, at atmospheric pressure. The main objective was to examine the influence of different parameters on the mass transfer kinetics during osmotic treatment. The observed system’s responses were: water loss, solid gain, and water activity. The optimum osmotic conditions (temperature of 40 °C, treatment time of 4.1 h and concentration 67 %), were determined using response surface method, by superimposing the contour plots of each process variable, and the responses were: water loss=0.46, solid gain=0.15, and water activity=0.79. Transport coefficients, for both solids and water transfer and energy of activation for all samples were also determined. [Projekat Ministarstva nauke Republike Srbije, br. TR-31055]

Segmented polyurethanes based on poly(dimethylsiloxane), currently used for biomedical applications, have sub-optimal biocompatibility which reduces their efficacy. Improving the endothelial cell attachment and blood-contacting properties of PDMS-based copolymers would substantially improve their clinical applications. We have studied the surface properties and in vitro biocompatibility of two series of segmented poly(urethane-dimethylsiloxane)s (SPU-PDMS) based on hydroxypropyl- and hydroxyethoxypropyl- terminated PDMS with potential applications in blood-contacting medical devices. SPU-PDMS copolymers were characterized by contact angle measurements, surface free energy determination (calculated using the van Oss-Chaudhury-Good and Owens-Wendt methods), and atomic force microscopy. The biocompatibility of copolymers was evaluated using an endothelial EA.hy926 cell line by direct contact assay, before and after pre-treatment of copolymers with multicomponent protein mixture, as well as by a competitive blood-protein adsorption assay. The obtained results suggested good blood compatibility of synthesized copolymers. All copolymers exhibited good resistance to fibrinogen adsorption and all favored albumin adsorption. Copolymers based on hydroxyethoxypropyl-PDMS had lower hydrophobicity, higher surface free energy, and better microphase separation in comparison with hydroxypropyl-PDMS-based copolymers, which promoted better endothelial cell attachment and growth on the surface of these polymers as compared to hydroxypropyl-PDMS-based copolymers. The results showed that SPU-PDMS copolymers display good surface properties, depending on the type of soft PDMS segments, which can be tailored for biomedical application requirements such as biomedical devices for short- and long-term uses. [Projekat Ministarstva nauke Republike Srbije, br. 172062]

Osmotic treatment (OT) is important food preservation method and complementary treatment in food processing industry because of the mild processing temperature, base waste material and low energy requirements. OT by gentle lowering the water content increases shelf life of food samples without unnecessary changes in dry product quality. Decrease of water content by osmosis involves immersion of food samples in hypertonic medium. Sugar beet molasses (SBM) in the past few years has proven to very efficient hypertonic solution for OT of fruit, vegetables, fish and pork meat. The process was carried out under atmospheric pressure at temperature of 20°C for 5 hours in SBM osmotic solutions. The monitored responses of OT process were: dry matter content (DMC), water loss (WL), solid gain (SG) and water activity. After five hours of immersion in SBM (80 % w/w) solution responses were: DMC=58.862±1.714, WL=0.496±0.011, SG = 0.128±0.011 and aw=0.836. Microbiological profile analysis of dehydrated chicken meat have confirmed safety.

The research was conducted with the aim of examining the presence of toxic elements (Pb, Cd, As and Hg) and essential elements (Zn, Cu, Fe i Mn) ions in selected agricultural soil and wheat samples by ICP mass spectrometry. An overall toxic element index was calculated by taking into account each element assay, which contributed with the same weight into final result. Correlation between toxic microelements contents in soil and wheat was monitored. Correlation analysis, ANOVA and F-test were applied for statistical evaluation of obtained results. The calculated mean and median levels of contamination were compared with the recommended or regulated maximum levels according to the European Commission and the national legislation.

Present study investigated effects of plasticizer contribution on structural, barrier and mechanical properties of corn starch based edible films. Films were obtained from solutions (containing gelatinized starch, polyol, guar-xantan gum modified mixture and water) by casting it on a Petri dish. Sorbitol acted as a plasticizer and guar-xantan modified mixture had role to enable better film folding and handling. Sorbitol was used in concentrations: 100, 130 and 160% (dry starch basis). The film proved to be strong, moderately flexible with good barrier properties to oxygen and water vapor. It was estimated that oxygen and water vapor permeability increases as plasticizer content in the film increases. Mechanical strength of films decreases due to plasticizer addition.

After functional phase, packaging becomes waste that is recycled or disposed of in landfills. Recently, numerus packages have been developed for assessing the packaging risk on the environment. We applied Gabi 4 Education software on polymer product packaging for meat products. The objective of first part of the paper was characterization of materials used for meat and meat products packaging in terms of mechanical and barrier properties. Results show that tested materials are able to keep protective atmosphere and contribute to the quality and sustainability of the product. Air permeability was 3.60 and 26.60 ml/m224h, and water vapor was 6.90 and 9.50 ml/m224h, respectively, for foils 1 and 2, as a result of different film composition. In second part, based on real data, Gabi 4 Education software is applied. The obtained results showed that organic compounds emissions have the highest impact on human health and the most damaging environmental impact observed was the emission of CO2.

Mass transfer of pork meat cubes (M. triceps brachii), shaped as 1x1x1 cm, during osmotic dehydration (OD) and under atmospheric pressure was investigated in this paper. The effects of different parameters, such as concentration of sugar beet molasses (60-80%, w/w), temperature (20-50ºC), and immersion time (1-5 h) in terms of water loss (WL), solid gain (SG), final dry matter content (DM), and water activity (aw), were investigated using experimental results. Five artificial neural network (ANN) models were developed for the prediction of WL, SG, DM, and aw in OD of pork meat cubes. These models were able to predict process outputs with coefficient of determination, r2, of 0.990 for SG, 0.985 for WL, 0.986 for aw, and 0.992 for DM compared to experimental measurements. The wide range of processing variables considered for the formulation of these models, and their easy implementation in a spreadsheet calculus make it very useful and practical for process design and control.

This study is focused on the behavior of five new deposits of heavy clays from Serbia, with the aim to evaluate their potential suitability as raw materials in rough ceramic applications. The Pfefferkorn plasticity coefficient (PC) and drying susceptibility using Bigot’s curve were measured for each raw sample. Thermodilatometric analysis (TDA) showed the behaviour of dry products during firing. Samples groups were fired in the range of 850°C - 1000°C. Water absorption capacity (WAC) and compressive strength (CS) were done in order to characterize clays after firing. Linear regression models were used to fit the results. Mathematical tools were used to determine statistical difference of major oxides content, shaping moist and compressive strength of dry laboratory products, using post-hoc Tukey`s HSD test. The chemical and mineralogical compositions of samples do not differ considerably, but their possible application does. All studied clays seem to be easily adaptable to a correct brick making process.

The main objective was to examine the influence of different osmotic parameters on the mass transfer kinetics during osmotic treatment of pork meat (M. triceps brachii). The system’s response parameters observed were: water loss (WL), solid gain (SG), final dry matter content (DM) and water activity (aw). The optimum osmotic parameters seem to be: osmotic time of 4 h, molasses solution concentration of 72% and solution temperature of 45oC. These conditions were determined using Response Surface Methodology (RSM), and by superimposing the contour plots of each process variable. The predicted responses for the optimum drying conditions were: DM of 64.5%, WL in the close vicinity of 0.53, SG about 0.15 and aw in the range of 0.83 to 0.84. [Projekat Ministarstva nauke Republike Srbije, br. TR-31055]

In this paper the quality of spelt pasta with addition of inulin HPX, which is positively contributing to the nutritive changes of the product, is investigated. Mixolab characteristics of spelt flour are indicating that it may be a good tool for determining a raw material quality for pasta. Inulin HPX was replacing spelt flour in the quantity of 0.5 or 10%. It is shown that the presence of inulin in pasta can be clearly distinguished from other polysaccharides by 13C MAS NMR spectroscopy. Simultaneous increase in area of the peak positioned at 81, 74, 64 and 58 ppm, obtained during deconvolution analysis of initial spectra, is directly associated with the increase in the content of inulin in the corresponding samples. Obtained data points that NMR spectrum can be used in the quality control for inulin identification, in a new high fibre product with functional properties and altered nutritive characteristics.

Enzymatic and non-enzymatic browning of mild-heat processed spreads, based on basil and cheese was monitored as color changes, by means of multivariate color image analysis. The objective of the study was to assess the antioxidative potential of lactoferrin with combinations of ascorbic, citric, lactic acid, and NaCl on prolonged lipid oxidation in fresh basil-based spreads. The 'browning' process, occurring in various foods, can be monitored by an algorithm describing the color properties of digitalized images, expressed by its color coordinates. The images were taken with a CCD camera, and afterwards transformed to frequency color distribution of color coordinate values. Different concentrations of organic acids had main influence on browning process, while lactoferrin and NaCl presence had no significant effect. The determined values of Peroxide Value (PV), Acid Value (AV) and oxidative induction time, determined by Differential Scanning Calorimetry OITDSC (for both 0th and 30th day) were the input values for further calculation.

The applicability of Peleg equation was examined for the description of mass transfer during osmotic dehydration (OD) of apple in sugar beet molasses. Mass transfer was investigated in terms of water loss (WL) and solid gain (SG), during OD in 40-80% sugar beet molasses solutions, at 45, 55 and 65ºC. High regression coefficients obtained for Peleg constants (R2>0.975) indicate good fit to the experimental data. The Peleg rate constant varied from 0.144 to 0.785 (g/g i.s.w.) and from 2.006 to 4.436 (g/g i.s.w.) for WL and SG, respectively. The Peleg capacity constant varied from 1.142 to 1.553 (h g/g i.s.w.) and from 8.254 to 11.930 (h g/g i.s.w.) for WL and SG, respectively. The equilibrium WL∞ and SG∞ were estimated using the Peleg model. In addition, the activation energy (Ea) for WL and SG was determined from the relationship between the Peleg rate constant and Arrhenius equation.

The aim of the present work is to optimize fermentation process of whole cabbage heads of white cabbage (cultivar 'Futoški' and hybrid 'Bravo' were considered within this research). Both cabbages were subjected to fermentation process, with addition of 1- 2% NaCl, at temperature 18-22oC. Different organic acids contents (oxalic - OK1, lactic - OK2, acetic - OK3, malic - OK4, citric - OK5, succinic - OK6 and formic- OK7) within cabbage leaves and brine were monitored during 80 days. Principal component analy­sis exerted good discrimination capabilities for different samples of 'Futoški' and hybrid 'Bravo' cabbage heads fermentation process, while standard score helped in optimal process parameters determination.

The presented paper describes an investigation of osmotic treatment of nettle leaves in two different osmotic solutions (sugar beet molasses and ternary solution), under atmospheric pressure, at room temperature. The main objective was to examine the influence of type of osmotic agents and immersion time on the mass transfer phenomena during osmotic treatment. Different kinetics parameters were monitored (water loss, solid gain, water loss to solid gain ratio, weight reduction, normalized solid content and normalized moisture content), after 30-90 min of process. Principal Component Analysis showed good discrimination capabilities for different samples, while Standard Score was used in optimal process parameters determination.

This research was conducted in order to examine the mass transfer kinetics, during osmotic dehydration of celery leaves (Apium graveolens) in two different osmotic solutions (sugar beet molasses and the mixed solution of sodium chloride and sucrose), under atmospheric pressure, at room temperature. The significance of used hypertonic solutions and immersion time on the various kinetics parameters (water loss, solid gain and dehydration efficiency index) were tested during the process, using Analysis of variance. Principal component analysis and Cluster analysis were used for characterization of different samples, and standard score analysis was applied in optimal process parameters determination.

The IGPC Engineering Department designed a project for the reconstruction of the copolymer production plant at "Zeolite Mira", Mira, Italy, using technology developed in the laboratories of the IGPC. The capacity of the reconstructed plant was increased from 17,000 to 25,000 t/y, in 1991 and the product quality was also improved.The product meets all quality regulation, as well as environmental regulations. There is no waste materials, and precautions were chosen to provide safe operation. This process is fully automatized, and the product has uniform quality. The production process can be controlled manually, which is necessary during start-up, and repairs.

The IGPC Engineering Department designed basic projects for a wet hydrate dissolution plant, using technology developed in the IGPC laboratories. Several projects were completed: technological, machine, electrical, automation. On the basis of these projects, a production plant of a capacity of 75,000 t/y was manufactured, at "Zeolite Mira", Mira (VE), Italy, in 1997. and 1998, increasing detergent zeolite production, from 50,000 to 100,000 t/y. Several goals were realized by designing a wet hydrate dissolution plant. The main goal was increasing the detergent zeolite production. The technological cycle of NaOH was closed, and no effluents emitted, and there is no pollution (except for the filter cake). The wet water glass production process is fully automatized, and the product has uniform quality. The production process can be controlled manually, which is necessary during start - up, and repairs. By installing additional process equipment (centrifugal pumps and heat exchangers) technological bottlenecks were overcome, and by adjusting the operation of autoclaves, and water glass filters and also by optimizing the capacities of process equipment.

The IGPC Engineering Department designed the basis technological and machine projects for a detergent zeolite complex, on the basis of which a pilot plant with an initial capacity of 5,000 t/y was constructed in 1983 within Birač-Zvornik production complex. Additional projects were done afterwards and the starting capacity increased to 200,000 t/y in 1988. This plant became the biggest producer of detergent zeolite in the world. These projects were manufactured on the basis of specific technology developed in the laboratories of the IGPC.Several goals were realized by designing a detergent zeolite production complex. This technology was an innovation, because a new approach in detergent zeolite production was developed. The product meets all quality demands, as well as environmental regulations. The detergent production process is fully automatized and the product has uniform quality. There is no waste material in detergent zeolite production, because all products with unsatisfactory quality are returned to the process. The production process can be controlled manually, which is necessary during stanrt-up, and repairs.

The IGPC Engineering Department designed basic projects for powder detergent production plant, using technology developed in the IGPC laboratories, in 1998. - 2000. Several projects were completed: technological, machine, electrical, automation. On the basis of these projects, a production plant with a capacity of 25,000 t/y was manufactured, at "Delta In", Zrenjanin, in 2000.This technology was an innovation, because new approach in mixing a powder materials was used, as well as introducing a new type of dryer in detergent production. The product meets all quality demands for detergents with high specific weight (1000 g/l), as well as environmental regulations. The detergent production process is fully automatized, and the product has uniform quality. There is no waste material in detergent zeolite production, because all products with unsatisfactory quality are returned to the process. The production process can be controlled manually, which is necessary during start-up, and repairs.