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Starch is extensively used in the food industry as a texture modifier, a fat substitute, and in other applications. To optimise starch functional properties for specific use, it is subjected to various modifications. High-voltage electrical discharge (HVED) treatment, as a non-thermal and rapid process, was applied in this research as a single method and in combination with phosphorylation in order to explore its potential for improving starch physicochemical properties. Maize, wheat, potato, and tapioca starches were modified, and Na5P3O10 and Na2HPO4 were used for phosphorylation. Starch gelatinisation parameters (by DSC) ; paste clarity ; and contents of amylose, damaged starch, and resistant starch were determined ; and FTIR- -ATR spectra were recorded. All modifications reduced the enthalpy of gelatinisation and decreased contents of amylose, resistant starch, and damaged starch. The effect of the HVED treatment on starch properties depended on starch type and combinations with chemicals. HVED could act as an aid in the starch phosphorylation process since the properties analysed were more effectively improved when HVED was combined with phosphorylation than by phosphorylation alone.

Structural, conductive and dielectric properties of hybrid Polypyrrole (PPy)-TiO2 nanocomposite-coated polyamide fabric (PA-PPy/TiO2) synthesized by in-situ oxidative polymerization of pyrrole on t...

Resistant starch (RS) is a part of insoluble dietary fiber, and it could be recognized as a functional food ingredient in some types of confectionery products that lack dietary fiber. Unlike dark and milk chocolate, white chocolate does not contain fat-free cocoa solids rich in dietary fiber. In the present study, 5%, 10%, and 15% of white chocolate were substituted with RS in order to improve the nutritional value of enriched white chocolate. The influence of RS on rheological, textural, and thermal properties of the chocolate fat phase was firstly investigated, and then further influence on physical properties, dietary fiber content, and sensory characteristics of enriched white chocolates were investigated. The obtained results showed that enriched chocolates had increased content of total dietary fiber and reduced total fats and protein content in accordance with the added amount of RS. At the same time, RS increased viscosity and reduced the hardness and volume mean diameter in enriched chocolates in accordance with the added amount. RS improved the nutritional composition of white chocolate by increasing the content of dietary fiber. At the same time, RS did not impair the color and sensory characteristics of enriched white chocolates.

The oligo(ethylene glycol) dimethacrylate (OEGDMA), one of the most commonly utilized crosslinking monomers, was used to tailor thermoresponsive POEGDMA hydrogels by varying the monomer/solvent feed ratio (from 10 to 100 wt% of monomer). For the first time, synthesis of different POEGDMA homopolymeric networks was performed by gamma radiation, and due to the expected thermoresponsiveness their temperature-dependent properties were extensively analysed. The sol-gel study was performed as the first step after radiation-induced synthesis. The swelling properties were investigated over the wide pH (2.2–9.0) and temperature (5–80 °C) range. Characterization of structure and properties was additionally conducted by SEM, DSC, FTIR, and UV–Vis spectroscopy. The results indicated that all POEGDMA hydrogels showed a high gel content, inverse thermoresponse and volume phase transition temperature (VPTT) with no respect to initial preparation. On the other hand, by altering the monomer/solvent ratio in the prepolymerisation mixture a large diversity in the microstructure, swelling capacity and VPTT was obtained. © 2019 Elsevier Ltd This is the peer-reviewed version of the following article: Suljovrujic, Edin, Zorana Rogic Miladinovic, Maja Micic, Denis Suljovrujic, and Dejan Milicevic. "The influence of monomer/solvent feed ratio on POEGDMA thermoresponsive hydrogels: Radiation-induced synthesis, swelling properties and VPTT." Radiation Physics and Chemistry 158 (2019): 37-45. [http://dx.doi.org/10.1016/j.radphyschem.2018.12.034] Published version available at: [http://vinar.vin.bg.ac.rs/handle/123456789/8048]

The electrochemical behaviour of potential antitumor benzimidazole derivatives (benzo[b]thieno[2,3-b]pyrido[1,2-a]benzimidazoles and benzimidazo[1,2-a]quinolines) bearing one or two piperazine substituents was studied at a glassy carbon electrode (GCE) using cyclic and square-wave voltammetry in a wide range of pH values and potential scan rates. The electrochemical oxidation of the studied benzimidazoles proceeded via one or two electrode reactions assigned to the oxidation of one or two piperazine substituents, respectively. The oxidation of piperazine ring involved the transfer of two electrons and one proton in a pH-dependent, kinetically controlled electrode reaction, followed by a homogenous chemical reaction (EC mechanism). Both the reactants and the products of EC reactions were strongly adsorbed on the GCE surface. The electrochemical reduction occurred in one quasireversible, pH-dependent step, followed by a chemical transformation of the electrochemically formed product. The proposed reduction mechanism was related to the cyano moiety. The assignment of electroactive sites in molecules of interest was confirmed by theoretically calculated, using the PM6 method, differences of Net atomic charges between the cation (or anion) and neutral molecule.

The addition of brewer’s spent grain (BSG), sugar beet pulp (SBP) and apple pomace (AP), on the nutritional properties of directly expanded snack products based on corn grits was investigated. Snack products were produced in a laboratory single screw extruder with the addition of 5, 10 and 15% d. m. of these by-products in corn grits. Chemical composition, total phenolic content, antioxidant activity, dietary fiber, resistant starch, starch damage and pasting properties of the mixtures and extruded samples were determined. Extrusion process and by-product additions had a significant effect on the proximate chemical composition. All three by-products increased contents of both soluble and insoluble dietary fiber, while the extrusion caused a reduction of insoluble fiber and increase of soluble fiber. After the extrusion process starch damage and antioxidant activity increased, while resistant starch content and total polyphenol content decreased. According to obtained results, it can be concluded that the investigated by-products can be used in the production of nutritionally more valuable corn snacks.

Recently, the enrichment of chocolate has become a very interesting topic, along with the management of food industry by-products, such as cocoa shells. Cocoa shells could be a great raw material for the cocoa industry, both for economical reasons (maximized utilization of cocoa beans) and for their functional properties (increased fiber content). In this research, we used untreated and high-voltage electrical discharge (HVED)-treated cocoa shells in the production of chocolate. Different proportions of cocoa mass were replaced with cocoa shells to produce dark and milk chocolates in a ball mill. Additionally, dark chocolate with 15% and milk chocolate with 5% of shells were chosen for further research and to study the alteration of the composition. The rheology, particle size distribution, hardness, and color were determined for all the prepared samples. Treated cocoa shells provided chocolates with inferior physical properties compared to chocolates with untreated shells. Therefore, untreated cocoa shells were selected for further analysis. The addition of both treated and untreated cocoa shells resulted in softening and darkening of samples, which could have a positive effect for consumers. On the other hand, the particle size distribution and rheology were negatively affected. Further research is needed to find a solution for these problems.

Sugar beet pulp (SBP) is a by-product of the sugar industry in which the dietary fiber content ranges from 73% to 80%. Compared to cereal fibers mainly used in biscuit production, sugar beet fibers are gluten free and have a perfect ratio of 2/3 insoluble fiber. In this work, sugar beet pulp was extruded with corn grits (ratios of corn grits to sugar beet pulp in extrudates were 85:15, 70:30, and 55:45), and the obtained sugar beet pulp extrudates (SBPEs) were used for improving the nutritional quality of cookies. The wheat flour in cookies was replaced with SBPEs in the amount of 5, 10, and 15%. The influence of three factors (the percentage of sugar beet pulp in the SBPEs, the size of the SBPE particles, and the percentage of wheat flour substituted with SBPEs) and their interactions on the nutritional quality of cookies, as well as their physical and sensory characteristics are examined using the Box–Behnken experimental design. The addition of extruded sugar beet pulp (SBPEs) significantly increased the amount of total dietary fiber and mineral matter of cookies. On the whole, the addition of SBPEs increased cookie hardness, but the hardness decreased with an increase in extrudate particle size. Sensory characteristics (except for the taste) were the most influenced by extrudate particle size.

Three fractions of tobacco waste (scrap, dust and midrib) were subjected to a high voltage electric discharge (HVED) assisted extraction procedure under different experimental conditions: solvent:solid ratio (300, 500, 700 mL/g), frequency (40, 70, 100 Hz) and treatment time (15, 30, 45 min), in order to study the influence of these conditions on the content of chlorogenic acid. The content of chlorogenic acid ranged from 1.54 to 3.66 mg/100 g for scrap, from 1.90 to 2.97 mg/100 g for dust, and from 2.30 to 3.38 mg/100 g for midrib extract, showing a strong dependence on the applied process parameters. The temperature change and the change in pH and electrical conductivity of the extracts after high voltage discharge treatment were also observed. The studied process parameters showed a statistically significant effect on the chemical and physical properties of the extracts from tobacco waste as well as on the content of chlorogenic acid, indicating the potential of HVED assisted processes in the separation of chlorogenic acid from tobacco industry waste. Multiple regression analysis was used to fit the results for the chlorogenic acid to a second order polynomial equation and the optimum conditions were determined.

The aim of this research was to explore the use of a high-voltage electrical treatment (HVED) as a substitute for heating during the phosphorylation of maize starch. Starch was treated with HVED, phosphorylated with Na2HPO4 or Na5P3O10 with and without thermal treatment and phosphorylated in combination with HVED prior to and after the chemical modification. When starch was phosphorylated with Na2HPO4, HVED was more efficient in catalyzing reaction (3.89 mg P/kg for 30 min HVED in relation to 0.43 mg P/kg for thermal treatment), whereas with Na5P3O10 similar P content was achieved as with thermal treatment (0.76 P/kg for 30 min HVED in relation to 0.86 mg P/kg). The order of HVED and chemical reactions did not have a marked effect on phosphorous content. In combination with Na2HPO4, HVED pre-treatment had a more pronounced effect on the solubility and water absorption, whereas post-treatment was favoured with Na5P3O10. Mean diameter was increased by all treatments, where HVED had a marked effect. Enthalpy of gelatinization ranged from 11.76 J/g for starch treated with Na5P3O10 and 10 min-HVED to 13.58 J/g for Na5P3O10 treated sample. G′ and G″ increased after both thermally and HVED enhanced phosphorylations, with a slightly more pronounced effect of the HVED.

Chocolate is a product that has a high content of fat and sugar. The addition of fibers and polyphenols in chocolate is increasingly being applied and studied in recent years. Since chocolate is a food product that has sensitive rheological properties, any addition of components that are not part of the standard recipe may have a significant influence on physical, chemical and sensory properties. Although cocoa is rich in polyphenols, their share in chocolate depends on the share of cocoa parts and the parameters during processing. Nutritional value of chocolate may be improved by addition of additional sources of nutritious compounds. This paper gives an overview of recent research regarding addition of fiber and polyphenols to chocolate.

With the aging of the western population, more and more people are affected by the neurodegenerative Alzheimer's and Parkinson's disease. Inhibitors of acetylcholinesterase (AChE) have proven to be effective in the treatment of disease symptoms. We report the QSAR regression model for the estimation of potency of a set of 94 structurally diverse compounds (oximes, N-hydroxyiminoacetamides, 4-aminoquinolines and flavonoids) to inhibit AChE, pKi (AChE). The model is based on three simple descriptors: the valence molecular connectivity index of the zero-order, 0χv, combined with the number of 10-membered rings (nR10) and number of hydroxyl groups in a molecule (nOH). QSAR model yielded r = 0.947, S.E. = 0.51 and S.E.cv= 0.53; the range of pKi (exp) = 6.03. It showed its stability when the set of 94 compounds was enlarged, comprising 184 compounds in total (r = 0.886, S.E. = 0.85 and S.E.cv = 0.88; the range of pKi (exp) = 10.21), resulting in regression parameters which were similar, although only for 0χv coefficients within the limits of S.E. (0.167(13) and 0.172(16) for the set with 94 and 184 compounds, respectively. The predictive power of the model was shown by the prediction of pKi values for 61 randomly chosen compounds (S.E.test = 0.86) from the calibration model made on the other 123 compounds (S.E. = 0.85), all taken from the pool of 184 compounds. QSAR descriptors 0χv, nR10 and nOH were well chosen for describing the interactions of the AChE active site (amino acid interaction) with ligands through the estimation of the inhibitory potency.

The stability of chocolate is mainly influenced by cocoa butter re-crystallization during storage, shown through fat bloom (appearance of white layers of cocoa butter on chocolate surface). The aim of this study was to examine the influence of cocoa shell addition on stability of dark and milk chocolate over one year storage period. Dark and milk chocolates were produced in a ball mill. Four chocolates were produced, two with the addition of cocoa shell (5% in milk and 15% in dark) and two control chocolates without the addition. Chocolates were stored at room temperature. The effect of cocoa shell on chocolate stability was examined by determining total color change and whiteness index (calculated from parameters L*, a* and b* determined using chromameter), total polyphenol content (TPC) (by Folin Ciocalteau method) and thermo-physical properties (using differential scanning calorimetry). Total color change and whiteness index were lower in chocolates with cocoa shell than in control samples. Over a period of one year, milk and dark chocolate with cocoa shell had lower melting enthalpy of fat on the surface of chocolate. Total polyphenol content in all chocolates did not change significantly through the storage period, although chocolates with cocoa shell had lower TPC because the part of the cocoa liquor was replaced with cocoa shell. From these results, it can be concluded that chocolates enriched with cocoa shell are stable during storage and that the shell actually positively affects fat melting enthalpy and total color change of chocolates.

Chocolate is considered as both caloric and functional food. Its nutritional properties may be improved by addition of fiber, however, this may reduce polyphenols content. The aim of this research was to determine the influence of cocoa shell addition (as a source of fiber) and its combination with different ingredients (cocoa butter equivalents (CBE), emulsifiers, dairy ingredients) on polyphenols of dark and milk chocolates. Total polyphenol (TPC) and total flavonoid (TFC) contents were determined spectrophotometrically, identification and quantification of individual compounds by high pressure liquid chromatography and antioxidant capacity by ferric reducing antioxidant power (FRAP) assay. Results showed that even though addition of cocoa shell to chocolate results in reduced contents of TPC, TFC, and individual compounds, it is not significant compared to ones reported by other authors for commercial chocolates. Other ingredients influence determined values for all investigated parameters, however, additional research is needed to reveal exact mechanisms and implications.

The prospects of sparkling wine production by the ‘Champenoise’ method using alginate- immobilised yeast cells were examined. Grape varieties dominant in quantity were selected within the group of recommended and permitted varieties of Kutjevo vineyards, located in the eastern part of continental Croatia. Research revealed that there are no influential variations in the principal physicochemical and sensory characteristics between sparkling wines obtained through immobilised yeast and traditional sparkling method. The analysis of aroma compounds showed minor differences between samples. Observed oenological parameters assessed in the final products did not show any relevant oenological differences, with the exception of alcohol content, which was slightly higher in sparkling wines made with yeast cells immobilised with calcium alginate beads. According to this research, the sensory properties of the produced sparkling wines, compared to sparkling wine produced with free yeast, did not show any significant differences. On the full-scale obtained results indicate that some of the selected varieties can be sorted as suitable for the production of sparkling wine using immobilised yeast cells.

Cocoa shell is a by-product of the chocolate industry that is rich in dietary fiber and bioactive components. In this research, the influence of high voltage electric discharge (HVED) treatment on chemical and physical characteristics of the cocoa shell, i.e., the effects of applied time and frequencies on grinding ability, water binding capacity (WBC), dietary fibers and tannin content was investigated. HVED had a significant influence on the chemical and physical properties of cocoa shell, all of which could be linked to changes in fiber properties. Along with the fiber content, grinding ability and water binding capacity were increased. These properties have already been linked to fiber content and soluble/insoluble fiber ratio. However, this research implies that change in fiber properties could be linked to tannin formation via complexation of other polyphenolic components. Additional research is needed to verify this effect and to establish mechanisms of tannin formation induced by HVED and its influence on fiber quantification.

© 2020 Taylor & Francis Group, LLC. In addition to currently used methods of gas chromatography with flame ionization detector or mass spectroscopy detection (GC–FID and GC–MS) for the analysis of seized heroin, a novel rapid high-performance liquid chromatography with tandem mass spectrometry (HPLC–MS/MS) method for detection and quantification of the main alkaloids was developed. This method for detection and quantification of heroin, papaverine, noscapine, and acetyl thebaol was validated and applied to analysis of seized heroin street samples. The method is rapid (6 min) and implies a low solvent consumption (0.75 mL min−1), suitable as an alternative method for GC–MS for heroin samples stored at elevated temperatures. The method was successfully tested on seized heroin samples.

Cocoa shell is one of the by‐products obtained in chocolate industry which was considered as waste for a very long time. Recently, the presence of high‐valuable bioactive components in cocoa shell was recognized, and research on the pallet of food products enriched with cocoa shell is increasing. The most abundant bioactive components of untreated cocoa shell (UCS) are theobromine (3.906 ± 0.070 mg/g), caffeine (0.646 ± 0.055 mg/g), and (+)‐catechin (0.290 ± 0.005 mg/g), followed by gallic acid (0.147 ± 0.041 mg/g) and (−)‐epicatechin (0.165 ± 0.099 mg/g). Furthermore, the impact of concentration (1.5 and 3% of cocoa shell in water), high‐voltage electric discharge (HVED) treatment (40 and 80 Hz), and treatment time (15, 30, and 45 min, respectively) on bioactive compounds content was evaluated. Statistically significant differences between treatment conditions were obtained. Generally, water‐HVED treatment at 40 Hz has lower impact on bioactive components than water, and water‐HVED at 80 Hz, therefore, can have a significant effect on future treatments of materials rich in bioactive compounds. PRACTICAL APPLICATIONS: HVED is an innovative nonthermal processing technique that has mechanical and electrical effect on the product resulting with lower costs and increase of functional properties. This study has shown that HVED causes lower decrease of phenolics and methylxanthines in cocoa shell which can have a significant effect on future treatments of materials rich in bioactive compounds. Because it is not recorded in scientific literature that HVED treatment was used on cocoa shell so far, it will help in future research and applications of cocoa shell in the food industry.

The aim of this research was to examine the influence of pasteurisation of cocoa liquor at different temperatures (115, 120, 125 and 140 °C) and 3-week-storage time at 40 °C on microbial safety, peroxide value, polyphenol, and flavan-3-ol content. Peroxide value of the cocoa liquor increased after both, pasteurisation and storage, but not significantly. Although total polyphenol content decreased, flavan-3-ol content was stable during the investigated period. Microbial quality was satisfying, and the most stable mass was the one treated at 140 °C.

Penicillium expansum is a necrotrophic plant pathogen among the most ubiquitous fungi disseminated worldwide. It causes blue mould rot in apples during storage, transport and sale, threatening human health by secreting patulin, a toxic secondary metabolite that contaminates apples and apple-derived products. Nevertheless, there is still a lack of sufficient data regarding the resistance of different apple cultivars to P. expansum, especially ancient ones, which showed to possess certain resistance to plant diseases. In this work, we investigated the polyphenol profile of 12 traditional and 8 conventional apple cultivar and their resistance to P. expansum CBS 325.48. Eight polyphenolic compounds were detected, the most prominent were catechin, epicatechin and gallic acid. The highest content of catechin was detected in ‘Apistar’—91.26 mg/100 g of fresh weight (FW), epicatechin in ‘Bobovac’—67.00 mg/100 g of FW, and gallic acid in ‘Bobovac’ and ‘Kraljevčica’—8.35 and 7.40 mg/100 g of FW, respectively. The highest content of patulin was detected in ‘Kraljevčica’ followed by ‘Apistar’—1687 and 1435 µg/kg, respectively. In apple cultivars ‘Brčko’, ‘Adamčica’ and ‘Idared’, patulin was not detected. Furthermore, the patulin content was positively correlated with gallic acid (r = 0.4226, p = 0.002), catechin (r = 0.3717, p = 0.008) and epicatechin (r = 0.3305, p = 0.019). This fact indicates that higher contents of gallic acid, catechin and epicatechin negatively affected and boost patulin concentration in examined apple cultivars. This can be related to the prooxidant activity of polyphenolic compounds and sensitivity of P. expansum to the disturbance of oxidative status.

This study aimed to establish a procedure for pomegranate peel (PP) valorization and attainment of stable extracts with preserved bioactive compounds. The technology applied was spray drying with carbohydrate-based (maltodextrin, MD) and protein-based (whey protein, WP) carrier materials in different concentrations (80, 100, and 120%). What was analyzed was the impact of the type and concentration of carrier material on the stability and quality of the final encapsulated powder. The best results were achieved when the PP extract was microencapsulated with the carbohydrate-based carrier (100%), where it had the highest encapsulation efficiency (EE) (88.63%), hygroscopicity (15.17%), and water solubility index (87.04%). The moisture content was in the range of 3.69–4.60% and 4.21–5.84% for MD and WP, respectively, indicating that both are suitable for long-term storage. It was observed that changes in carrier concentration significantly influenced most of the powders’ physicochemical properties. Microencapsulation using MD yielded a higher content of punicalin, punicalagin, gallic, and ellagic acid than those with WP. Overall results demonstrated that carbohydrate-based microencapsulation can be utilized efficiently for the protection of powder stability and phytochemical characteristics.

In continuation of our investigation of the dependence of the first electrochemical oxidation potential, Ep1, on the electronic structures of flavonoids, the potentials of nine additional flavonoids (hesperetin, daidzein, kaempferol, acacetin, naringin, neohesperidin, hesperidin, quercitrin, and gossypin) were assessed using square-wave voltammetry on a glassy-carbon electrode in aqueous buffer solutions with a pH of 3 and 7. Our standard model for the estimation of the Ep1, based on the sum of atomic orbital spin populations over the carbon atoms in the skeleton of the radical molecule, Σ s(C) AOSPRad, yielded S.E. = 0.063 and S.E.cv = 0.072 on this enlarged set of 29 flavonoids. We also introduced a new complementary model that yielded similar statistics, S.E. = 0.055 and S.E.cv = 0.059. This model was based on the differences in the net atomic charges between cations and neutral flavonoids also summed over the carbon atoms in their skeleton ( Σ s(C) ΔNACCat-Neut). Such an excellent agreement between Σ s(C) ΔNACCat-Neut and Ep1 may be proof that the electrochemical oxidation of all 29 flavonoids starts with ionization, i.e. abstraction of an electron, at both of the pHs indicated.

Volatile organic compounds in honey represent a fingerprint of a specific honey and therefore could significantly affect the quality of honey brandy. In addition, during fermentation, yeast synthesise volatiles also affecting aroma and quality of brandy. The aim of this research was to assess the impact of immobilized cell fermentation on volatile aroma of honey brandies produced from acacia and chestnut honey. Aroma profile was determined using GC/FID and sensory analysis was conducted according to German DLG model. The results showed that immobilized cell technique had resulted in honey brandies with lower ester contents, but significantly higher content of volatile organic compounds from honey.

Orientation and radiation processing of polymeric materials are the main steps in certain modern technologies and have extensive applications. The properties of such treated polymers can change significantly in time and under various exploitation conditions and therefore, investigation of some specific effects of aging and storage of these systems is of great importance, although the overall degradation behavior of iPP is well known. In this work, isotactic polypropylene (iPP) samples were oriented via solid-state stretching at elevated temperature (at 100°C, up to draw ratio λ=20). This was followed by gamma irradiation in the air (up to 700 kGy) and/or thermo-oxidative (TO) aging (in oxygen, at 100°C, up to 8 days) and/or storage (at room temperature, up to 3 years). As the iPP is very sensitive to orientation and degradation, microstructures were analyzed by optical (OM) and scanning electron microscopy (SEM). Wide-angle X-ray diffraction (WAXD) and differential scanning calorimetry (DSC) were used to monitor changes in structure and recrystallization. Considering the fact that at higher irradiation doses (>200 kGy), iPP starts to gel under the ambient conditions, gel measurements were employed to determine the yield of network formation induced by irradiation of stretched structures. Irradiation, TO degradation and storage, can induce substantial alternations of (di)electric properties which can be properly connected to the changes in microstructure and crystallinity; therefore, dielectric loss analysis was performed in a wide temperature range and polar groups that were introduced in apolar iPP by oxidation were considered as tracer groups. © 2021 Elsevier Ltd

Poly-l-lactide (PLLA) and hydroxyapatite/poly-l-lactide (HAp/PLLA) are two widely used biomaterials for three-dimensional scaffolds, drug release matrices and implantable medical devices for reparation of bone tissue; diversity in the initial preparation and filler content has a significant influence on different properties such as morphology and crystallinity, thus playing a considerable role in most of these applications. For this reason, PLLA and HAp/PLLA samples with a large difference in crystallinity (from below 20% to over 70%) and filler content (up to 86 wt% of HAp nanoparticles with an average diameter of 80 nm) were prepared and consequent dissimilarities in morphology, crystallinity and thermal properties were investigated by scanning electron microscopy (SEM), differential scanning calorimetry (DSC), wide angle X-ray diffraction (WAXD) measurements and Fourier transform infrared (FTIR) spectroscopy. Special attention was devoted to analyzing data obtained from thermal measurements. A three-phase model was employed in order to describe the heat capacity step decline in the nanocomposite; the evolution in different polymer fractions, the crystalline fraction and the mobile and rigid amorphous fractions, with filler content was determined. © 2017 Society of Chemical Industry

Chocolate production is a complex process during which numerous chemical reactions occur. The most important processes, involving most of the reactions important for development of the proper chocolate flavor, are fermentation, drying and roasting of cocoa bean, and chocolate conching. During fermentation, formation of important precursors occurs, which are essential for further chemical reactions in the following processes of chocolate production. Roasting is one of the most important processes due to the occurrence of Maillard’s reactions, during which aroma compounds are formed. In this paper, we have reviewed the most important chemical reactions that occur with proteins, carbohydrates, lipids, and polyphenols. Additionally, we present other components that may be naturally present or form during the production process, such as methylxanthines, aldehydes, esters, ketones, pyrazines, acids, and alcohols.

Poly(l-lactide) (PLLA) is an extensively employed biodegradable semicrystalline polymer with usage from implantable medical devices and drug release matrices to environmentally friendly packaging materials. Since the morphology and crystallinity considerably determine the application field, PLLA samples with a large variation in crystallinity (going from below 20% to over 70%) were prepared by different procedures. Subsequent differences in morphology, crystallinity and thermal properties were followed by scanning electron microscopy (SEM), wide angle X-ray diffraction (WAXD) measurements and differential scanning calorimetry (DSC). The value of the enthalpy of melting of a perfectly (100%) crystalline PLLA was determined (ΔH f = 115.7 J/g). © 2019, © 2019 Taylor & Francis Group, LLC.

The aim of this research was to enrich extruded snack with cocoa husks. It was added to corn grits in 5%, 10%, and 15% d. m., the moisture was set to 15%, and the prepared samples were extruded in a laboratory single screw extruder at 135/170/170°C, with 4 a mm‐round die and a screw with the compression ratio of 4:1. Physical properties, resistant starch (AOAC 2002.02), starch damage (AACC 76‐31), polyphenol content (Folin‐Ciocalteau), and antioxidant activity (DPPH) were determined. Although the addition of cocoa husk resulted in harder, darker snacks with increased retrogradation tendency, these properties were still in the acceptable range. Resistant starch, polyphenol content and antioxidant activity of the flips increased proportionally with the addition of cocoa husks, while starch damage slightly decreased, indicating that cocoa husk may be successfully employed as an agent for the fortification of nutrients.

I have shown that by averaging antioxidant activity (AA) values measured by different methods it is possible to obtain an excellent correlation (R2=0.960) between the first electrochemical oxidation potential, Ep1, and AA. Separate correlations using the AA values obtained with each of the four methods [R2 were 0.561 for diphenyl-1-picrylhydrazyl (DPPH), 0.849 for Folin Ciocalteu reagent (FCR), 0.848 for the ferric-reducing ability of plasma (FRAP), and 0.668 for the Trolox equivalent antioxidant capacity (TEAC)] were all worse, and in some cases not useful at all, such as the one for DPPH. Also, the sum of atomic orbital spin populations on the carbon atoms in the skeleton of radicals (s(C) Σ AOSPRad), calculated with the semi-empirical parameterisation method 6 (PM6) in water, was used to correlate both Ep1 and AA, yielding R2=0.926 and 0.950, respectively. This showed to be a much better variable for the estimation of Ep1 and AA than the bond dissociation energy (BDE), R2=0.854 and 0.901 for Ep1 and AA, respectively, and especially the ionisation potential (IP), R2=0.445 and 0.435 for Ep1 and AA, respectively., U radu je pokazano da je usrednjivanjem vrijednosti antioksidacijskih aktivnosti (AA) mjerenih različitim metodama moguće dobiti izvrsno slaganje (R2=0,960) između prvog elektrokemijskog oksidacijskog potencijala (Ep1) i AA. Pojedinačne korelacije AA vrijednosti dobivene svakom od četiriju metoda [R2 je 0,561 za difenil-1-pikrilhidrazil (DPPH), 0,848 za Folin-Ciocalteu reagens (FCR), 0,848 za sposobnost plazme da reducira željezo (FRAP) i 0,668 za Trolox ekvivalent antioksidacijske aktivnosti (TEAC)] bile su lošije, a u nekim slučajevima potpuno nekorisne, kao što je primjerice korelacija s DPPH. Također, zbroj spinskih populacija atomskih orbitala ugljikovih atoma u skeletu molekule radikala (s(C) Σ AOSPRad), izračunana semi-empirijskom parametrizirajućom metodom 6 (PM6) u vodi, korelirana je s Ep1 i AA, dajući R2=0,926 i 0,950. Pokazano je da je to puno bolja varijabla za procjenu vrijednosti Ep1 i AA od energije disocijacije veze (BDE), R2=0,854 i 0,901 za Ep1 i AA, a naročito od ionizacijskog potencijala (IP), R2=0,445 i 0,435 za Ep1 i AA.

The aim of this research was to investigate influence of different fermentation processes (by immobilized yeast cells and classical fermentation) and different cherry varieties (Maraska, Montmorencys and Kelleris) on the chemical and sensorial characteristics of cherry brandies. Cherry brandies were analyzed to determine chemical composition, aroma profile and sensory properties. Cherry brandies produced by immobilized yeast cells had a higher content of aldehydes, but lower content of total acids, total extract, higher alcohols and esters compared to the samples produced by classical fermentation process. Furfural was not detected in cherry distillates produced by immobilized yeast cells, while distillates produced by classical fermentation process had very low content. Cherry brandies produced by classical fermentation process had significantly higher content of benzaldehyde which has great influence on aroma of cherry brandies. Ethyl octanoate which is considered one of the most important contributors to the aroma of alcoholic distillates was found in the highest concentrations in Maraska distillates. The best evaluated sample was brandy produced from Maraska cherry variety fermented by immobilized yeast cells followed by brandy produced also from Maraska cherry variety, but by classical fermentation process.

Cabbage is an important source of bioactive compound, which is available throughout the year. However, a lot of different traditional, and hybrid varieties with different levels and composition of bioactive compounds can be found on the market. The aim of the study was to obtain quantitative results showing comparative differences between different white cabbages (&ldquo, Čepinski&rdquo, &ldquo, Varaždinski&rdquo, Bravo&rdquo, Ogulinski&rdquo, ) from Croatia. Morphometric parameters and physicochemical composition were determined while using standard procedures. Phenolic acids were determined using high-performance liquid chromatography and volatile compounds were analysed by the solid-phase micro-extraction gas chromatography with mass spectrometry (SPME-GC-MS) smethod. The results showed that studied cabbage cultivars differed in physicochemical composition and morphological traits. Six phenolic acids were identified and quantified, whereas a sinapic acid was the most dominant component (65.9&ndash, 78.15 mg/kg). Aldehydes, esters, alcohols, and terpenes were the major classes of organic volatile compounds present in the studied cabbages. &ldquo, which has never been analysed before, showed to contain the highest amount of d-limone (40.75 &micro, g/L) and allyl isothiocyanate (1090.26 &micro, g/L), the most important volatile compounds responsible for the fresh cabbage flavour. The presented results mark off &ldquo, cultivar as valuable for larger production and further examination.

In this work, fast continuously operated microextraction of polyphenolic compounds using ATPSs formed form NADESs and potassium hydrogen phosphate was developed. The effects of the NADES mass, extraction time, extraction temperature, salt concentration and gallic acid concentration on the extraction efficiency have been investigated in batch experiments. Furthermore, a 2D model considering convection in the flow direction and diffusion in two directions at steady-state conditions was developed and the developed extraction method was verified using two realistic samples (aqueous extracts of lemon balm and mint). Using a continuous microextractor, an extraction efficiency of approximately 94% was achieved for a residence time of τ = 3.65 s, which is a significant improvement compared to the batch process where an extraction efficiency of 88% was achieved for a residence time of t = 15 min. Also, the proposed 2D mathematical model described the extraction in a continuously operated micro extractor with high accuracy.

Amino-substituted benzamide derivatives are very attractive compounds due to their capacity to act as powerful antioxidants by scavenging free radicals. Knowledge on electrochemical oxidation mechanisms plays an important role in understanding the free radical scavenging activity of antioxidants. In this paper, the electrochemical oxidation of four amino-substituted derivatives [N-(4-aminophenyl)-2-hydroxybenzamide (1), N-(4-aminophenyl)-2-hydroxy-4-methoxybenzamide (2), N-(4-aminophenyl)-2-methoxybenzamide (3), N-(4-aminophenyl)-3,4,5-trihydroxybenzamide (4)] in an aqueous buffer solution was studied by means of cyclic and square-wave voltammetry, and probable reaction mechanisms have been proposed. In compounds 1–3, the primary amino group was found to be the main electroactive centre undergoing a complex, pH-dependent oxidation process with the transfer of two electrons and two protons. This reaction occurs in one step or in two separate steps, depending on the pH of the medium. A possible explanation for this electrochemical behaviour is discussed. The final products of initial electrochemical oxidation of amino-substituted benzamides 1–3 are quinonediimine derivatives that undergo further chemical transformation into electroactive forms. Oxidation of compound 4 proceeds through two sequential reactions; the first anodic reaction is the oxidation of the trihydroxyphenyl group to the corresponding o-quinone, followed by the oxidation of a primary amino group. Considering the oxidation potentials, and bearing in mind that lower/less positive potential implies better radical scavenging activity, the order of antioxidant activity of the here studied amino-substituted benzamides is: 4 > 2 > 1 > 3.

This paper is a continuation of our studies on the dependence of the first electrochemical oxidation potential, Ep1, on the electronic structures of flavonoids. For this purpose, a set of 20 flavonoids and their cation and radical forms were optimized by semi-empirical PM6 and DFT in water methods. Using differences in net atomic charges ΔNACCat-Neut calculated using PM6 we determined active OH oxygens. DFT in some cases gave different results, which were also in opposition to the literature. The models for the estimation of Ep1 based on the sum of atomic orbital spin populations on carbon atoms in skeleton of radicals, Σ s C AOSPRad, calculated by PM6 method yielded much better statistics than those calculated using DFT (S.E. = 0.064 vs. 0.118).

The aim of this study was to investigate the possibility of application of brewer's spent grain (BSG), sugar beet pulp (SBP) and apple pomace (AP) in production of corn snack products. Additionally, in the case of BSG and SBP the pectin (0.5% and 1% d. m.) was added in an attempt to resolve the problems of poor expansion and textural properties. Samples were extruded in the laboratory single screw extruder, and physical and sensory properties of obtained extrudates were determined. By-products addition decreased expansion ratio and fracturability, whereas bulk density and hardness increased. Pectin addition at level of 1% resolved the problem of poor expansion in the extrudates with BSG and SBP, which resulted in successful incorporation of all three by-products in the production of acceptable expanded corn snack products. By-products addition and extrusion process had a significant effect on color change, water absorption and water solubility indexes. Industrial relevance The production of nutritionally fortified snack products, with the acceptable physical and sensory properties is challenging. The addition of high-fibre and high-protein ingredients to starch based raw materials significantly affects the texture, expansion and overall acceptability of extruded snacks. This study provided a novel and effective way to resolve these problems in production of corn extrudates enriched with food industry by-products, by pectin addition. Furthermore, this investigation could partially help in the disposal of waste from the food industries in which the investigated by-products (brewer's spent grain, sugar beet pulp and apple pomace) are formed in large quantities.

Glass Ionomer Cements (GIC) have been widely used in clinical practice since they have a wide range of positive characteristics: chemical bonding to the tooth surface, fluoride release, a heat- expansion coefficient similar to the tooth, do not require an absolutely dry working area, less volumetric con- traction, good color stability. Physical properties can be improved by using external energy such as ultrasound and radiant heat (thermo-curing), which also accelerates chemical curing. Objectives: The aim of this study was to determine the most effective polishing technique and to compare the surface roughness of two Glass Ionomer Cements after treatment with heat (thermo- curing), and without heat treatment during the setting process. Materials and methods: Two polishing systems (Tungsten carbide burs and Sof-Lex discs) were used on two types of GIC (Equia Fil and Ketac Molar Universal). Bluephase 16i LED (Vivadent, Schaan Liechtenstein) light was used for the specimens treated with heat (thermo- curing). Samples without heat treatment are left for 10 minutes to chemically cure. Sur-face profilometar was used for measuring the mean surface roughness value (Ra). Results: Group with Mylar strip (control group) of each material showed the lowest (Ra) value. The Equia Fil mate- rial samples treated with heat (thermo-curing) achieved lower surface roughness values (Ra), and showed lower surface roughness values (Ra) after polishing with a Sof-Lex discs (p0.05) between polishing with Sof-Lex discs and Tungsten carbide burs. Conclusion: Based on the obtained results, it can be concluded that the smoothest surface roughness is achieved by the Mylar strip. Some types of Glass Ionomer Cements can obtain better surface polishing with heat treatment (thermo-curing).

This paper studies the electronic structures of the 14 flavonoids and their cation and radical forms involved in the first electrochemical oxidation step, associated with the oxidation peak appearing at potential Ep1. The sum of differences in Net atomic charges on atoms in skeleton of cations and neutral flavonoids ( Σ s ( C ) ΔNACCat.-Neut.) and the sum of Atomic orbital electron and spin populations on atoms in skeleton of radicals ( Σ s ( C ) AOEP and Σ s ( C ) AOSP) revealed that electron distribution between skeleton atoms and active OH oxygen is more evenly distributed in cations and radicals of flavonoids that are more prone to oxidation. Those less susceptible to oxidation are more polarized, i.e. the skeleton becomes more positively charged. Also, Σ s ( C ) AOSP proved to be an excellent descriptor for modelling the first oxidation potential, especially in combination with Σ s ( C ) pzAOEP (common model for pH = 3 and 7 yielded R2 = 0.978 and S.E. = 0.43).

In this work, thermal diffusivity of crystalline high-density polyethylene samples of various thickness, and prepared using different procedures, was evaluated by transmission gas-microphone frequency photoacoustics. The samples composition analysis and their degree of crystallinity were determined from the wide-angle X-ray diffraction, which confirmed that high-density polyethylene samples, obtained by slow and fast cooling, were equivalent in composition but with different degrees of crystallinity. Structural analysis, performed by differential scanning calorimetry, demonstrated that all of the used samples had different levels of crystallinity, depending not only on the preparing procedure, but also on sample thickness. Therefore, in order to evaluate the samples thermal diffusivity, it was necessary to modify standard photoacoustic fitting procedures (based on the normalization of photoacoustic amplitude and phase characteristics on two thickness levels) for the interpretation of photoacoustic measurements. The calculated values of thermal diffusivity were in the range of the expected literature values. Besides that, the obtained results indicate the unexpected correlation between the values of thermal diffusivity and thermal conductivity with the degree of crystallinity of the investigated geometrically thin samples. The results indicate the necessity of additional investigation of energy transport in macromolecular systems, as well as the possible employment of the photoacoustic techniques in order to clarify its mechanism. 18th International Conference on Photoacoustic and Photothermal Phenomena (ICPPP), Sep 06-10, 2015, Novi Sad, Serbia

Polyester fibers gained significant share from all other man-made fibers, but despite numerous advantages a characteristic static electricity generation is still seeking innovative solutions. In order to improve electrical properties of poly(ethyleneterephthalate) (PET) fabric, coating consisting of polyaniline/TiO2 (PANI/TiO2) nanocomposite was deposited on its surface. Coating was synthesized in acidic medium by the chemical oxidative polymerization of aniline with ammonium peroxydisulfate CAPS) in the presence of colloidal TiO2 nanoparticles (d similar to 4.5 nm) and PET fabric. The morphology, molecular structure and dielectric properties of PANI/TiO2 nanocomposites were studied by scanning electron microscopy (SEM), Raman and dielectric spectroscopies. SEM analysis revealed the formation of non-uniform PANI coating on the reference PET sample. In contrast, uniform PANI/TiO2 coating on the surface of PET fabric was generated when TiO2 nanoparticles were engaged. The existence of conductive emeraldine salt form of PANI and phenazine units was confirmed by Raman spectroscopy. Formation mechanisms of PANI and PANI/TiO2 coatings on PET fabrics were proposed. The presence of TiO2 nanoparticles significantly affected the dielectric properties (permittivity and loss tangent) and AC conductivity of PANI/TiO2 coated PET fabrics. PET fabrics coated by PANI/TiO2 nanocomposite showed up to two orders of magnitude higher conductivity in the measured frequency region compared to PANI coated PET fabric. (C) 2015 Elsevier B.V. All tights reserved.

Using molecular graph theory we studied the binding of NSFRY-NH2 and 12 related pentapeptide amides to Cu(II) as a model system for atrial natriuretic factor (ANF) peptide interactions with copper. Linear regression models based on the valence connectivity index of the 3rd order (3χv) reproduced experimental stability constants (log β) for 1N, 2N, 3N, and 4N coordinated complexes with the standard error of 0.30-0.39 log β units. We developed separate models for seven tyrosinic (N=28) and five non-tyrosinic peptides (N=20), and a common model for both kinds of peptides (N=48) with an indicator (dummy) variable. The results indicate additional aromatic stabilisation in 4N complexes due to metal cation-π interactions with tyrosine but not with the phenylalanine residue. We have also amended the log K and log K* values to correct miscalculations published by Janicka-Klos et al. in 2013

Understanding the molecular-level behavior of ionic liquids (ILs) at IL-solid interfaces is of fundamental importance with respect to their application in, for example, electrochemical systems and electronic devices. Using a model system, consisting of an imidazolium-based IL ([C2Mim][NTf2]) in contact with a sapphire substrate, we have approached this problem using a complementary combination of high-resolution X-ray reflectivity measurements and atomistic molecular dynamics (MD) simulations. Our strategy enabled us to compare experimental and theoretically calculated reflectivities in a direct manner, thereby critically assessing the applicability of several force-field variants. On the other hand, using the best-matching MD description, we are able to describe the nature of the model IL-solid interface in appreciable detail. More specifically, we find that characteristic interactions between the surface hydroxyl groups and donor and acceptor sites on the IL constituents have a dominant role in inducing a multidimensional layering profile of the cations and anions.

Changes in the structure and dielectric properties of low-density polyethylene were created by gamma irradiation in air, deionised water and nitrogen. Role of irradiation media on dielectric and charge trapping behaviour was studied through dielectric loss and thermally stimulated discharge current measurements. Changes in magnitude, position and activation energy of all dielectric relaxations (gamma, beta and alpha) were found to be dependent on crosslinking and oxidative degradation, two competitive processes which can be tuned by radiation dose and media. Largest changes in the position and activation energy were found for the beta relaxation due to its cooperative nature.