The content of polyphenols and carotenoids in three apricot cultivars depending on stage of maturity and geographical region

During the ripening of three apricot cultivars (“Keckemetska ruza”, “Madjarska najbolja” and “Velika rana”) grown in two different geographical region of Croatia the changes of polyphenols and carotenoids were determined by using high-performance liquid chromatography (HPLC) with UV–Vis photo diode array detection. The content of individual polyphenols during ripening was quite similar, whereas their amount differed significantly. Immature fruits showed the highest level of polyphenols, which decreased at semi-mature fruits and did not change remarkably in commercial mature fruits. Among polyphenols, flavan-3-ols, chlorogenic acid and quercetin-3-rutinoside were dominant in all ripening stages of all apricot cultivars. The quantity of polyphenols during apricot fruits ripening depended on cultivars, while the region of cultivation did not have remarkable influence on polyphenols amount. During ripening carotenoids increased significantly especially β-carotene which represented 70–85% of the total carotenoid content. Besides β-carotene, in all apricot cultivars γ-carotene was found. α-Carotene, zeaxantin and lutein were found in cv. “Madjarska najbolja” and in cv. “Velika rana” α-carotene and lutein were determined. The region of cultivation and the cultivar were important factors, which influenced the carotenoid amount of apricot fruits, and this content was higher in cultivars grown in Mediterranean region.     

Epidemiology of end‐stage renal disease and hemodialysis treatment in Serbia at the turn of the millennium

The study presents the epidemiological features of patients treated with renal replacement therapy (RRT) in Serbia from 1997 to 2009 and compares the results of hemodialysis treatment in 1999 and 2009. Epidemiological data were obtained from the National Registry of RRT patients and data on hemodialysis treatment from special surveys conducted in 1999 and 2009. Within the period 1997–2009 the incidence of patients on RRT increased from 108 to 179 per million population (pmp), prevalence rose from 435 to 699 pmp, while mortality rate fell from 20.7% to 16.7%. The frequency of patients with glomerulonephritis decreased, while that of patients with diabetes and hypertensive nephropathy increased. In late 2009 there were 5208 patients receiving RRT in Serbia. Within the examined period new hemodialysis and reverse osmosis equipment were purchased, high‐flux dialyzers with synthetic membranes were increasingly used and the number of patients receiving hemodiafiltration increased to 17.6%. Kt/V greater than 1.2 was recorded in 16% of the patients in 1999 but 52% in 2009. Options for correction of anemia and mineral disorders have also improved. The percentage of patients with HbsAg (13.8% vs. 4.8%) as well as anti‐hepatitis C virus antibodies positive patients (23.2% vs. 12.7%) was significantly lower in 2009 than in 1999. Both the incidence and prevalence of RRT patients in Serbia are rising continuously, while the mortality rate is falling. More favorable conditions for dialysis treatment have brought about significant improvement in the results over the last 10 years.     

Antioxidant activity versus cytotoxic and nuclear factor kappa B regulatory activities on HT-29 cells by natural fruit juices

The antioxidant activity (free radical scavenging ability and lipid oxidation inhibitory activity) and the activity in cell culture [influence on HT-29 human colon cancer cell viability and nuclear factor kappa B (NF-κB) activation] of natural fruit juices from red grape, strawberry, cherry and sour cherry were investigated in vitro. Analysis of polyphenolic composition of fruit juices showed the dominant presence of anthocyanins (cyanidin-3-glucoside, cyanidin-3-rutinoside, peonidin-3-rutinoside, pelargonidin-3-glucoside), anthocyanidins (procyanidins B1, B2 and B3), flavonoids (glucosides of myricetin, quercetin and kaempferol), and phenolic acids (neochlorogenic acid, chlorogenic acid, ellagic acid, p-coumaroylquinic acid) in juices. DPPH test and β-carotene bleaching method indicated that grape, strawberry, cherry and sour cherry natural juices (at the concentration of 2.5%) showed very strong free radical scavenging (75–92%) and antioxidant activity (71–94%). In addition, at the concentration of 0.01% they showed complete inhibition of copper-induced oxidation of human LDL (low density lipoprotein). In contrast, selected fruit juices did not show cytotoxic effects on HT-29 cells and NF-κB inhibitory activity (at the concentrations of 0.5 and 2%). Results of this study showed no correlation between the antioxidant activity of natural fruit juices from red grape, strawberry, cherry and sour cherry and their effect on HT-29 cell viability and NF-κB inhibitory activity.     

On controllability and system constraints of the linear models of proton exchange membrane and solid oxide fuel cells

In this paper we first show that the linear models of proton exchange membrane (polymer electrolyte membrane, PEM) and solid oxide (SO) fuel cells, commonly used in power and energy literature, are not controllable. The source of uncontrollability is the equation for pressure of the water vapor that is only affected by the fuel cell current, which in fact is a disturbance in this system and cannot be controlled by the given model inputs: inlet molar flow rates of hydrogen and oxygen. Being uncontrollable these models are not good candidates for studying control of dynamic processes in PEM and SO fuel cells. However, due to their simplicity, they can be used in hybrid configurations with other energy producing devices such as photovoltaic (solar) cells, wind turbine, micro gas turbine, battery (ultra capacitor) to demonstrate some other phenomena, but not for control purposes unless the hybrid models formed in such hybrid configurations are controllable. Testing controllability of such hybrid models is mandatory. Secondly, we introduce some algebraic constraints that follow from the model dynamics and the Nernst open-loop fuel cell voltage formula. These constraints must be satisfied in simulation of considered fuel cell modes, for example, via MATLAB/Simulink or any other computer software package.     

Chemometric evaluation of binary mixtures of alginate and polysaccharide biopolymers as carriers for microencapsulation of green tea polyphenols

In this study principal component analysis and artificial neural networks were used to evaluate the potential of using binary mixtures of sodium alginate and other polysaccharide biopolymers as the carriers for microencapsulation of green tea bioactive compounds. Using binary mixtures of alginate and adjunct biopolymers increased the particle size (from 722 to 1344 µm) and textural parameters of the microbeads. Chemometric techniques revealed the combination of biopolymers and their ratio as the main factors influencing the encapsulation performance. The combination of alginate with hydroxypropyl methylcellulose and locust bean gum enabled to retain the highest (-)-epigallocatechin gallate and caffeine contents, the highest total phenols encapsulation efficiency, and their most retarded release in water, confirming these as the best delivery systems of polyphenol-type active compounds and signifying their potent food applications.     

Investigation of sorbents synthesised by mechanical–chemical reaction for sorption of As(III) and As(V) from aqueous medium

Efficiency of Fe₂O₃ and mixture of Fe₂O₃ and MnO₂ nanoparticles synthesised by mechanical–chemical reaction for inorganic As(III) and As(V) sorption was examined. Sorbents (Fe₂O₃ and mixture Fe₂O₃:MnO₂ = 3:1) synthesised by mechanical–chemical treatment in planetary ball mile with different milling times were tested by batch experiments. Experimental data were fitted both to Freundlich and Langmuir adsorption models. Efficiency of sorption was in good correlation with the time of milling in case of pure oxide. There were small differences in sorption between As(III) and As(V). In the case of mixture of oxides results were different. The best results were obtained by 30 min of milling. With prolonged milling, the sorption decreased to 3 h and after that increased again. These results were explained by phase transition. Sorption kinetics, influence of pH and the presence of other anions were examined for mixture of oxides with highest sorption capacity. The bioavailability of sorbed arsen was tested using modified Tessier procedure.     

Assessing the antifungal activity of a new oral lipid-based amphotericin B formulation following administration to rats infected with Aspergillus fumigatus

The purpose of this study was to assess the antifungal activity of a new oral amphotericin B (AmpB) lipid-based formulation following administration to rats infected with Aspergillus fumigatus. Aspergillus fumigatus inoculum (2.1-2.5 × 10⁷ colony forming units [CFU]) were injected via the jugular vein; 48h later male albino Sprague-Dawley rats (350-400 g) were administered either a single oral dose of AmpB incorporated into Peceol (50 mg AmpB/kg), physiologic saline (nontreated controls) or Peceol alone (vehicle control) once daily for 4 days. To assess antifungal activity Brain, Lung, Heart, Liver, Spleen and Kidney sections were homogenized with normal saline (1 mL/g of tissue) and a 0.1-mL aliquot was spread plated onto a Sabourand dextrose agar plate. The plates were incubated for 48 hr at 37°C, at which time the number of fungal CFU were determined and corrected for tissue weight. In addition, plasma galactomannan antigen concentrations were determined. Data was reported as mean ± standard error of the mean. The AmpB-Peceol oral formulation significantly decreased total fungal CFU concentrations recovered in all the organs added together, brain CFU concentrations, spleen CFU concentrations and plasma galactomannan antigen concentrations compared to baseline. No significant differences in lung, heart, liver and kidney CFU concentrations between treatment and control groups were observed. Peceol vehicle control did not exhibit any antifungal activity. These findings suggest that a new oral lipid-based formulation of AmpB incorporated into Peceol can significantly decrease brain and spleen CFU concentrations and plasma galactomannan antigen concentrations compared to non-treated controls.