Joanna Szymońska

University of Agriculture in Krakow, Cracovia, Lesser Poland Voivodeship, Poland

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Publications (14)25.92 Total impact

  • [Show abstract] [Hide abstract]
    ABSTRACT: In the study interactions of dichromate ions with potato starch granules in high acidic aqueous solutions and at different temperatures were investigated. It was found, that the process underwent as a reduction of Cr2O72- to Cr3+ accompanied by formation of intermediate Cr5+ ions detected by the electron paramagnetic resonance (EPR) spectroscopy. The reactions took place after prior attaching of dichromate anions to the granules and resulted in lowering of the Cr2O72- initial content in the solution. The newly formed Cr3+ ions were both accumulated by the granules or remained in the solution. It was for the first time observed that quantity of such ions taken by the granules from the solution was noticeably higher compared to that delivered by trivalent chromium salt solution. It was revealed by the scanning electron microscopy coupled with the energy dispersive X-ray spectroscopy (SEM-EDX) that the chromium ions were not only adsorbed on the granule surface but also introduced into the granule interior and evenly distributed there. Activation energy of the reduction reaction equal to 65 kJ∙mol-1 and the optimal parameters of the process were established. Proposed mechanism could be useful for bioremediation of industrial effluents polluted by hexavalent chromium compounds.
    The Journal of Physical Chemistry B 05/2014; · 3.61 Impact Factor
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    ABSTRACT: Formation of free radicals due to mechanical crushing of potato starch granules in ethanol suspension has been investigated. Nature of the radicals, their quantity, as well as the storage and thermal stability were characterized by the electron paramagnetic resonance (EPR) spectroscopy aided by computer simulations. Room temperature EPR spectra obtained after starch milling indicated that the radical species were present in the system in the quantity positively correlated with the level of the starch granule damage dependent on the processing duration. The product species could be assigned to the carbon type radicals formed by mechanically induced α-1,4-glucosidic bond cleavage of the starch polysaccharides followed by a hydrogen abstraction from the glucose units. Mechanically fractured starch granules were vulnerable for the thermal treatment. Heating in the temperature range of 180–230°C resulted in more intense formation of thermally generated radicals in comparison to the native starch and non-heated milled starch. Storage stability of the radicals depended on the level of the granule destruction implying various ways of the radical annihilation. In addition, the kinetic data of the process are presented and the inter-radical transformations causing unexpected growth of the amount of thermally generated radicals at the initial stage of the starch storing are discussed.
    Starch - Starke 07/2013; 65(7‐8). · 1.22 Impact Factor
  • J. Szymonska, M. Targosz-Korecka, F. Krok
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    ABSTRACT: Nanomaterials already attract great interest because of their potential applications in technol., food science and medicine. Biomaterials are biodegradable and quite abundant in nature, so they are favored over synthetic polymer based materials. Starch as a nontoxic, cheap and renewable raw material is particularly suitable for prepn. of nanoparticles. In the paper, the structure and some physicochem. properties of potato and cassava starch particles of the size between 50 to 100 nm, obtained by mech. treatment of native starch, were presented. We demonstrated, with the aim of the SEM and the non-contact At. Force Microscopy (nc-AFM), that the shape and dimensions of the obtained nanoparticles both potato and cassava starch fit the blocklets - previously proposed as basic structural features of native starch granules. This observation was supported by aq. soly. and swelling power of the particles as well as their iodine binding capacity similar to those for amylopectin-type short branched polysaccharide species. Obtained results indicated that glycosidic bonds of the branch linkage points in the granule amorphous lamellae might be broken during the applied mech. treatment. Thus the released amylopectin clusters could escape out of the granules. The starch nanoparticles, for their properties qual. different from those of native starch granules, could be utilized in new applications. [on SciFinder(R)]
    Journal of Physics Conference Series 01/2009; 146:No pp. given.
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    ABSTRACT: An electron paramagnetic resonance (EPR) study was performed for potato and wheat starch containing Cu2+ ions as a paramagnetic probe. Distribution of water in the starch granules as well as the interactions between the copper and starch matrix of different crystalline structures were determined. EPR spectra of the native starches consisted of two different centers of Cu2+. One of them, giving at 293 and 77 K an EPR signal of axial symmetry with a well-resolved hyperfine structure (HFS), was assigned to the Cu2+ -starch complex in which Cu2+ ions strongly interacted with oxygen atoms of the starch matrix. Another Cu2+ species, exhibiting an isotropic signal at 293 K and an axial signal with resolved HFS at 77 K, was attributed to a [Cu(H2O)6]2+ complex freely rotating at room temperature and immobilized at low temperatures. Interaction of Cu2+ with the starch matrix and the relative number of the particular copper species depended on the crystallographic type of starch. Dehydration at 393 K resulted in elimination of the rotating complex signal and decrease of the total intensity of the EPR spectrum caused by clustering of the Cu2+ ions. Freezing at 77 K and thawing led to restoring of the spectrum intensity and reappearing of the signal of the [Cu(H2O)6]2+ complex. This effect, related to liberation of water molecules from the granule semicrystalline growth rings on freezing/thawing, was especially visible for wheat starch, indicating differences in the water retention ability of starch granules of different crystallographic structure.
    Biopolymers 09/2006; 82(6):549-57. · 2.88 Impact Factor
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    ABSTRACT: Water and methanol vapor adsorption isotherms for native and modified potato starch were investigated. For obtaining the best fit for the experimental data several models based on the BET approach was evaluated. The hypothesis that water is adsorbed on the starch granules at the primary and secondary adsorption sites as well as a concept considering the adsorbent fractality were also tested. It was found, that the equilibrium adsorption points in the examined range of relative humidity (0.03–0.90) were most accurately predicted by using a three-parameter model, proposed by Kats and Kutarov (1998). For methanol a good representation of experimental data was obtained using model proposed by Talu and Meunier (1996).
    Adsorption 01/2005; 11:757-761. · 1.55 Impact Factor
  • Joanna Szymońska, Krystyna Wodnicka
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    ABSTRACT: Influence of multiple freezing and thawing on the porosity of potato starch granules was determined with a nitrogen sorption method. As a consequence of the processing, the granule specific surface area and the size of granule pores significantly increased, whereas the true (helium) density of the granules noticeably decreased. The effect depended on freezing conditions and the moisture content in starch. The most pronounced result was achieved on gradual freezing of ambient native granular starch containing 13% (w/w) water. In that case, after 10 freezing/thawing cycles, specific surface area of granules increased from initial 0.36 to 1.64 m2/g. Single deep freezing in liquid nitrogen of oven-dried starch (8% w/w of moisture) in water suspension resulted in the increase of the granule initial total pore volume and the mean pore diameter by five and almost three times, respectively. The processing notably influenced wetting ability and α-amylase digestibility of the granules. The obtained data could be helpful in evaluation of storage stability of potato starch-based foodstuffs. Due to its modified physical properties, granular potato starch subjected to multiple freezing and thawing could be suitable for new applications in food technology or pharmacology.
    Food Hydrocolloids 01/2005; 19(4):753-760. · 3.49 Impact Factor
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    J Szymońska, F Krok
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    ABSTRACT: Surface studies at ambient conditions of potato starch granules subjected to multiple freezing and thawing, performed by a high resolution non-contact atomic force microscopy (nc-AFM), revealed some details of the starch granule nanostructure. After the treatment, a significant separation and a chain-like organisation of the granule surface elements have been observed. An accurate analysis of the granule surface nanostructure with a single amylopectine cluster resolution could be carried out. The oblong nodules of approximately 20-50 nm in diameter have been observed at the surface of the potato starch granules. The same size particles were precipitated by ethanol from gelatinized potato starch suspensions. They were also detected at the surface of oat and wheat starch granules. After multiple freezing and thawing, the eroded potato granule surface revealed a lamellar structure of its interior. The 30-40 nm inter-lamellar distances were estimated by means of nc-AFM. These findings fit previously proposed dimensions of the structural elements in the crystalline region of the starch granule. The observed surface sub-particles might correspond to the single amylopectine side chain clusters bundled into larger blocklets packed in the lamellae within the starch granule. The results supported the blocklet model of the starch granule structure.
    International Journal of Biological Macromolecules 12/2003; 33(1-3):1-7. · 2.60 Impact Factor
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    ABSTRACT: The influence of multiple freezing of water inside or outside the starch granule on the modification of starch properties has been investigated. Freezing in liquid nitrogen, followed by thawing was repeated in several subsequent cycles for native starch and dried starch–water suspensions (1:1.5 v/v). After such procedures, the precise structural analysis of the starch granule surfaces was carried out by high-resolution non-contact atomic force microscopy. Moreover, gelation characteristics, X-ray diffraction as well as the water and iodine sorption ability of the processed granules were estimated. Pronounced changes were found on the granule surface. After the fifth freezing, a well-ordered microstructure of the surface with distinct straight chains of fine particles of about 30 nm in diameter could be observed. The surface regularities were accompanied by some irreversible disruption of the granule inner structure indicated by changes of the starch crystallinity and in water adsorption. The freezing/thawing process also influenced the gelation characteristics, water solubility and water holding capacity, but did not change the branching characteristics of the studied starch granules.
    Carbohydrate Polymers. 01/2003;
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    ABSTRACT: Water vapour adsorption isotherms for native and modified potato starch were investigated. To obtain the best fit for the experimental data several models based on the BET approach were evaluated. The hypothesis that water is adsorbed on the starch granules at the primary and secondary adsorption sites as well as a concept considering the adsorbent fractality were also tested. It was found, that the equilibrium adsorption points in the examined range of relative humidity (0.03–0.90) were most accurately predicted by using a three-parameter model proposed by Kats and Kutarov.
    Applied Surface Science 01/2002; 196(1):150-153. · 2.54 Impact Factor
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    ABSTRACT: We have investigated ion-stimulated desorption of neutral molecules emitted from 8 keV Ar+ ion-bombarded self-assembled monolayers (SAMs) of phenethyl mercaptan (PEM) C6H5CH2CH2–SH and 2-(4′-methyl-biphenyl-4yl)-ethanethiol (BP2) CH3C6H4C6H4CH2CH2–SH deposited on Au(111) substrate. Neutral molecules were detected by laser postionization mass spectrometry. Only molecular fragments were detected from ion-bombarded systems. The mass spectra obtained for sputtered and gas phase fragments indicate that molecules recorded during ion bombardment were indeed emitted from the surface and were not the result of photofragmentation induced by the ionizing laser beam. From experimentally obtained time-of-flight (TOF) distributions, it was determined that the majority of desorbed neutral molecules leave the surface with very low translational energies. As the sample temperature is reduced, the distributions become broader and shift to longer flight times. The shift is more pronounced for molecules from BP2 and increases with the mass of the recorded molecular fragment. We postulate that the emission of molecules is initiated by processes which gently break molecular bonds (e.g., chemical reactions, secondary electrons). The formed fragments are loosely bound to the surface and can be removed by evaporation. At the investigated temperature range (170–350 K), the observed emission delay is attributed to the time required for the molecule to evaporate from the surface and is not influenced by the bond breaking rate.
    Nuclear Instruments and Methods in Physics Research Section B Beam Interactions with Materials and Atoms 01/2001; 182(1):148-154. · 1.27 Impact Factor
  • J Szymońska, F Krok, P Tomasik
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    ABSTRACT: Samples of oven-dried, air-dried, and moisturised potato starch (5, 13, and 24% w/w moisture content, respectively) were frozen in liquid nitrogen. Samples after thawing were studied by means of cross-polarised light beam microscope (CLBM), Fourier Transformation Infrared Spectroscope (FT-IR), powder X-ray diffractometer, and non-contact Atomic Force Microscope (nc-AFM). Rapid deep-freezing followed by thawing produced changes on the granule surface. They were accompanied by internal alteration manifested by FT-IR spectra and powder X-ray diffractograms. The results depended on the water content in the sample. Deep-freezing of moistened starch resulted in increased crystallinity of granules. It had minor effect on the granule aqueous solubility and characteristics of gelation.
    International Journal of Biological Macromolecules 08/2000; 27(4):307-14. · 2.60 Impact Factor
  • F Krok, J Szymońska, P Tomasik, M Szymoński
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    ABSTRACT: To assess the influence of the freezing process on the surface structure of a potato starch granule, a non-contact Atomic Force Microscopy (NC-AFM) investigation at ambient conditions has been undertaken. The observations were carried out for dried (oven-dried) and native (air-dried) starch. The obtained AFM images of the native starch granule surface demonstrated it as not uniformly smooth and having rough undulating appearance with layers of adsorbed water which could be removed by oven drying in 130°C. After freezing, the dried starch granule surface still consisted of nodules of about 100 nm in diameter. Significant changes in the granule surface appearance can be seen for dried starch samples frozen with some excess of water as well as for native starch samples frozen with its original water. Then the aggregation and polishing of the granules was observed and their surface revealed a microstructure with distinct ring-like protrusions of about 300 nm in diameter. Our observations tally with the amylopectine “blocket” starch granule structure model proposed in the literature and allowed to conclude that freezing may be a useful tool, among other methods, for modifying starch granule properties.
    Applied Surface Science 04/2000; 157(4):382-386. · 2.54 Impact Factor
  • Michal Uher, Joanna Szymońska, Anna Korenova, Piotr Tomasik
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    ABSTRACT: Chlorokojic acid was reacted with S2O3 2−, NO3 −, N3 −, I−, and SCN−. Only the three latter nucleophiles substituted the chlorine atom in the 2-CH2Cl group of kojic acid. In none of the products nucleophilic substitution at position 6 of the 4-pyrone could be found. Regular substituion of chlorokojic acid with I− (iodokojic acid), N3 − (azidokojic acid), and SCN− (thiocyanato and isothiocyanato kojic acids) was accompanied by formation of allomaltol. Reaction pathways for the formation of allomaltol and 6-substituted allomaltol derivatives are proposed. The latter has been formerly discovered in the reaction of chlorokojic acid with secondary amines.
    Monatshefte fuer Chemie/Chemical Monthly 01/2000; 131(3):301-307. · 1.63 Impact Factor
  • Joanna Szymońska, Franciszek Krok, Piotr Tomasik
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    ABSTRACT: Samples of oven-dried, air-dried, and moisturised potato starch (5, 13, and 24% w/w moisture content, respectively) were frozen in liquid nitrogen. Samples after thawing were studied by means of cross-polarised light beam microscope (CLBM), Fourier Transformation Infrared Spectroscope (FT-IR), powder X-ray diffractometer, and non-contact Atomic Force Microscope (nc-AFM). Rapid deep-freezing followed by thawing produced changes on the granule surface. They were accompanied by internal alteration manifested by FT-IR spectra and powder X-ray diffractograms. The results depended on the water content in the sample. Deep-freezing of moistened starch resulted in increased crystallinity of granules. It had minor effect on the granule aqueous solubility and characteristics of gelation.
    International Journal of Biological Macromolecules - INT J BIOL MACROMOL. 01/2000; 27(4):307-314.

Publication Stats

71 Citations
25.92 Total Impact Points

Institutions

  • 2000–2013
    • University of Agriculture in Krakow
      • Department of Chemistry and Physics
      Cracovia, Lesser Poland Voivodeship, Poland
  • 2006
    • Jagiellonian University
      • Faculty of Chemistry
      Kraków, Lesser Poland Voivodeship, Poland
    • Agricultural University of Szczecin
      Cracovia, Lesser Poland Voivodeship, Poland