CaO&CaSO4 and CaO&Al2(SO4)3 as Pectin Precipitants–Model of Overlapping Diffuse Layers

This work is concerned with the theoretical basis of novel sugar beet juice purification method using binary systems CaO&CaSO4 and CaO&Al2(SO4)3. The Gouy–Chapman–Stern (GCS) model of overlapping of diffuse layers of EDLs on pectin surface and that on Ca2+ and Al3+ ions, theoretically explains this method. The change of the zeta potential was used to quantitatively indicate overlapping of diffuse layers. For the experiment two model solutions of pectin (0.1 % w/w) were prepared, while the concentrations of CaO&CaSO4 and CaO&Al2(SO4)3 in the range of 50–500 g dm-3 were used. The greater decrease in the absolute value of zeta potential indicated greater overlapping of diffuse layers between pectin particles and Ca2+ and Al3+ ions and faster coagulation of pectin. The overlapping degree increased with increased concentration of these binary systems. Pectin with a greater surface charge and multivalent Al3+ from CaO&Al2(SO4), exerted a greater impact on the zeta potential. Optimal quantities of the applied binary mixtures were as follows: 256–640 mg g-1 pectin. This is much lower than CaO commonly used in the conventional process of sugar beet juice purification (about 9 g g-1 pectin)

Antioxidant Capacity of Nettle Leaves During Osmotic Treatment

Osmotic treatment (OT) of nettle leaves was assessed in various osmotic solutions (sugar beet molasses – SBM and ternary aqueous solution – TAS), at temperatures of 20, 35 and 50 °C, under the atmospheric pressure. The influence of the kind of utilized osmotic solution, process temperature and osmotic time on the antioxidant activity (AOC), expressed with the spectrophotometric assays (ABTS, FRAP and DPPH), as well as two direct current polarographic assays, Hydroxo Perhydroxo Mercury (II) complex assay, based on the decrease of anodic current and assay based on the decrease of a cathodic current of Hg (II) reduction. For determination of the total phenolic content Folin-Ciocalteu assay was used. The Relative Antioxidant Capacity Index (RACI), obtained by setting equal weight for every involved assay was applied in order to get an extensive comparison among analyzed samples and between the used assays. Based on these results, after the OT of nettle leaves in TAS, the AOC decreased, while the OT in SBM increased AOC values. The phenolic antioxidant coefficients (PAC), calculated as the ratio between particular AO capacity and TPC, were used to achieve a more comprehensive comparison between analysed samples, as well as applied assays. The results of RACI evaluation revealed that the most favorable osmotic treatment is the one performed for 5h at 35 °C

Structural characterisation of starch based edible films with essential oil addition

Present study investigated structure of starch based edible films with essential oil addition. Films were obtained from water solutions containing gelatinized modified starch, polyol, guar-xantan gum modified mixture and essential oil by casting it on a Petri dish and evaporating at room temperature for 72h. Both, glycerol and guar-xantan modified mixture, had role to improve film flexibility and enable better film folding and handling. Two sample groups were obtained: starch based edible films with black cumin oil addition and starch based edible films with black pepper oil addition. Both essential oils were added in three different concentrations. Starch based edible film without essential oil addition was used as blank shot. Structural properties were determined by analyzing spectra obtained by FT-IR Spectrometer in the spectral range of 4000–400 cm−1 with a 4.0 cm−1 resolution. Software Omnic 8.1. and TQ Analyst were used to operate the FTIR spectrometer, collect and present all the data. Results pointed to quantitative law dependency between added amount of essential oils and spectra absorption values for both sample groups and FTIR spectra were used to calculate coefficient of correlation

Granular flow in static mixers by coupled DEM/CFD approach

The mixing process greatly influences 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 behavior 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

Spatial distribution and identification of elements and oxides in surface sediments of the Boka Kotor bay

Ovo istraživanje sprovedeno je u Bokokotorskom zalivu radi procene kvaliteta površinskog sedimenata, a time i stanja morske sredine. ED-XRF metodom elementarne analize određen je sadržaj velikog broja elemenata i oksida u površinskim sedimentima uzorkovanih sa 12 lokacija u 2019. godini. Multivarijantnom statističkom analizom, kao što su analiza glavnih komponenati (PCA) i klaster analiza (CA), urađena je analiza dobijenih podataka kako bi se dobila sveobuhvatna raspodela ispitivanih elemenata po lokacijama u zalivu i njihovo poreklo, kao i sličnosti/razlike grupa uzoraka u hemijskom sastavu.This study was carried out in the Bay of Boka Kotor in order to assess the surface sediment quality and thereby to evaluate the status of the marine environment. The method of elementary analysis, ED-XRF was used to determine the content of elements and oxides in surface sediments sampled at 12 stations in 2019. Multivariate statistical methods, such as principal component analysis (PCA) and cluster analysis (CA) were used to analyse the data in order to obtain a comprehensive distribution of the examined elements according to locations in the bay, and their origin, as well as similarities/differences of samples in chemical composition.49. godišnja konferencije o aktuelnim problemima korišćenja i zaštite voda „Voda 2020“, Trebinje, 19. – 20. novembar 2020

Evaluation of water, sucrose and minerals effective diffusivities during osmotic treatment of pork in sugar beet molasses

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

Effects of temperature and immersion time on diffusion of moisture and minerals during rehydration of osmotically treated pork meat cubes

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