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

Assessing the Impact of Botanical Origins, Harvest Years, and Geographical Variability on the Physicochemical Quality of Serbian Honey

This study summarized the physicochemical analysis of 609 honey samples originating from the Republic of Serbia. Variations among honey samples from different botanical origins, regions of collections, and harvest years were exposed to descriptive statistics and correlation analysis that differentiated honey samples. Furthermore, most of the observed physicochemical parameters (glucose, fructose, sucrose content, 5-hydroxymethylfurfural (5-HMF) levels, acidity, and electrical conductivity) varied significantly among different types of honey, years, and regions. At the same time, no noticeable difference was found in diastase activity, moisture content, and insoluble matter. Based on the obtained results, 22 honey samples could be considered adulterated, due to the irregular content of sucrose, 5-HMF, acidity, and diastase activity. In addition, 64 honey samples were suspected to be adulterated. Adulterated and non-compliant samples present a relatively low percentage (14.1%) of the total number of investigated samples. Consequently, a considerable number of honey samples met the required standards for honey quality. Overall, these findings provide insights into compositional and quality differences among various types of honey, aiding in understanding their characteristics and potential applications

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

Comparison of methods of zeta potential and residual turbidity of pectin solutions using calcium sulphate/aluminium sulphate as a precipitant

The affinity of calcium ion binding from CaO used in the most common process of purification of sugar beet juice is relatively low. Therefore, large amounts of this compound are required. This paper presents the theoretical basis of a novel sugar beet juice purification method based on the application of the binary system CaSO4/Al2(SO4) . In order to monitor the process of coagulation and precipitation of pectin in the presence of CaSO4/Al2(SO4)3, two methods were compared: measurement of the zeta potential and of residual solution turbidity. The zeta potential of pectin solution was determined by electrophoretic method, while the residual turbidity was determined by spectrophotometry. Two model solutions of pectin (0.1 % w/w) were investigated. Studies were performed with 10 different concentrations of the binary solution CaSO4/Al2(SO4)3 (50 - 500 g dm-3). The amount of the precipitant CaSO4/Al2(SO4)3 (1:1 w/w) needed to achieve the minimum solution turbidity and charge neutralization of pectin particles (zero zeta potential) were measured and compared. Colloidal destabilization occurred before a complete neutralization of the surface charge of pectin particles (zeta potential ~ 0 mV). Optimal quantities (490 - 705 mg g-1 pectin) of the applied binary mixture, were obtained using both methods. This is much lower than the amount of CaO that is commonly used in the conventional process of sugar beet juice purification (about 9 g• g-1 pectin). The use of these precipitants could be important from both economic and environmental point of view. [Project of the Serbian Ministry of Education, Science and Technological Development, Grant no. 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

Osmotic dehydration of fish: principal component analysis

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