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Wyszukujesz frazę "Tuwalska, D." wg kryterium: Autor

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    Tytuł:
    Spiral-coil countercurrent chromatographic separation of betanin and betanidin ethyl-esters monitored by continuous ESI-MS/MS injection and LC-ESI-MS/MS
    Autorzy:
    Tuwalska, D.
    Szot, D.
    Wybraniec, S.
    Winterhalter, P.
    Jerz, G.
    Powiązania:
    https://bibliotekanauki.pl/articles/115897.pdf
    Data publikacji:
    2013
    Wydawca:
    Fundacja na Rzecz Młodych Naukowców
    Tematy:
    spiral-coil countercurrent chromatography (spCCC)
    betacyanin ethyl-esters
    betalains
    betacyanins
    betanin
    betanidin
    Opis:
    Betalains present in Beta vulgaris L. (Chenopodiaceae) have a high potential as natural pigments for food applications. They have been used as a substitute of synthetic dyes in processing of gelatine, strawberry yogurts, ice creams, fruits cocktails, candies and biscuits. The stability of betalains is strongly influenced by numerous factors – sugar content, and impact of light, oxygen, water activity, pH and temperature. A mixture of betacyanin mono-, di- and tri-ethyl-esters was separated by a large-volume spiral-coil countercurrent chromatography (spCCC) prototype which yielded fractions continuously off-line injected to an ESI-MS/MS device. This method yielded a reconstituted pigment profile and finally enabled the MS-target-guided isolation procedure for the whole spCCC-experiment. The individual fractions were analyzed by LC/ESI-MS/MS. Betanin and betanidin mono-, di- and tri-ethyl-esters as well as other decarboxylated derivatives were detected in the chromatograms. The ethyl-esters of betanin were only partially fractionated, but clearly fractionated from the ethyl-esters of betanidin which will be of great value for biological evaluations.
    Źródło:
    Challenges of Modern Technology; 2013, 4, 4; 21-25
    2082-2863
    2353-4419
    Pojawia się w:
    Challenges of Modern Technology
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Thermal degradation of 17-decarboxy-betanin monitored by LC-MS
    Autorzy:
    Szot, D.
    Starzak, K.
    Skopińska, A.
    Tuwalska, D.
    Wybraniec, S.
    Powiązania:
    https://bibliotekanauki.pl/articles/115566.pdf
    Data publikacji:
    2014
    Wydawca:
    Fundacja na Rzecz Młodych Naukowców
    Tematy:
    17-decarboxy-betanin
    betacyanins
    thermal degradation
    17-dekarboksy-betanina
    betacyjaniny
    degradacja termiczna
    Opis:
    A thermal stability study on 17-decarboxy-betanin depending on physicochemical process conditions was conducted. 17-decarboxy-betanin is one of betacyanin, natural origin pigments applied in food and pharmaceutical industry instead of artificial colorants. There is a need for searching of new non-toxic natural food components and this is a reason of increasing interest of betacyanins. As most derivatives of betanin obtained by decarboxylation, 17-decarboxy-betanin tends to degrade in the presence of some factors such as increased temperature or other conditions of the reaction environment [1]. This subject was investigated in this study because the stability of the pigments is still a significant issue limiting their wide application. The degradation of 17-decarboxy-betanin during heating in selected solutions: water as well as aqueous solutions of ethanol 50% (v/v), methanol 50% (v/v) and acetonitrile 50% (v/v) at pH in the range 3-8 was tested. As UV-Vis spectra indicate, 17-decarboxy-betanin tends to degrade mostly at pH 3, notwithstanding a type of solution. The products of degradation were identified by LC-DAD-ESI-MS. As a result of incubation at 85°C in different solutions, various mono-, bi- and tridecarboxylated as well as dehydrogenated derivatives were obtained. The dominant product of 17-de-carboxy-betanin degradation is 2,15,17-tridecarboxy-2,3-dehydro-betanin.
    Źródło:
    Challenges of Modern Technology; 2014, 5, 3; 32-36
    2082-2863
    2353-4419
    Pojawia się w:
    Challenges of Modern Technology
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    The effect of citric acid on stabilization of betanin solutions
    Autorzy:
    Skopińska, A.
    Szot, D.
    Tuwalska, D.
    Starzak, K.
    Osiadło, M.
    Wybraniec, S.
    Powiązania:
    https://bibliotekanauki.pl/articles/115716.pdf
    Data publikacji:
    2014
    Wydawca:
    Fundacja na Rzecz Młodych Naukowców
    Tematy:
    betanin
    betacyanins
    citric acid
    Beta vulgaris L.
    betanina
    betacyjaniny
    kwas cytrynowy
    Opis:
    Elevated temperature is known to be the most crucial factor influencing betanin integrity during food processing and storage. Nevertheless, certain chelating agents or antioxidants, such as acetic acid, may act as stabilizers. Therefore, the effect of citric acid on the stability of betanin – basic betacyanin – was investigated during the heating experiments in water as well as 50% and 95% (v/v) aqueous-organic solutions of methanol, ethanol and acetonitrile. The presence of citric acid in tested solutions affects betanin stability, especially in the 95 % solutions, in which the stabilizing effect of this compound is significantly higher than in aqueous solutions. However, some decrease of retention in 50% methanol was also observed. The main products of betanin thermal degradation in aqueous and aqueous-organic solutions were compounds characterized by absorption bands around the wavelength at 420 nm.
    Źródło:
    Challenges of Modern Technology; 2014, 5, 2; 19-24
    2082-2863
    2353-4419
    Pojawia się w:
    Challenges of Modern Technology
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Semi-synthesis of red beet betacyanin ethyl-esters by esterification
    Autorzy:
    Tuwalska, D.
    Starzak, K.
    Szot, D.
    Wybraniec, S.
    Winterhalter, P.
    Jerz, G.
    Powiązania:
    https://bibliotekanauki.pl/articles/115735.pdf
    Data publikacji:
    2014
    Wydawca:
    Fundacja na Rzecz Młodych Naukowców
    Tematy:
    betacyanin ethyl-esters
    betalains
    betacyanins
    betanin
    betanidin
    esterification
    estry etylowe
    betalainy
    betacyjaniny
    betanina
    betanidyna
    estryfikacja
    Opis:
    Red beet pigments recovered from Beta vulgaris L. (Chenopodiaceae), mainly consist of purple betacyanins, such as 15R/15S-betanin. Currently,this pigment class is intensively investigated in respect of stability in food systems. Quite popular is the use of red beet extracts in dairy products such as yoghurts, and ice-creams. So far, there are no issues of toxicity using these natural pigments in food – so they seem to be a very good alternative to replace synthetic dyes which had been frequently discussed for negative side-effects to human health. Betacyanins, the glycosidation products of betanidin are very polar and therefore water soluble pigments, which are biosynthetically derived from condensation of cyclo-DOPA and betalamic acid. The significant polarity of betacyanins requires the use of ion-pair reagents such as trifluoro-acetic acid (TFA) or other homologue fluorinated additives under standard separation conditions on larger scale in spiral coil countercurrent chromatography (spCCC). In our synthetic experiment, the polarity of the natural betacyanins was reduced. This omitted the use of toxic per-fluoro ion-pair reagents. The three carboxylic groups of the betanin pigment backbone were the target functional groups of the derivatisation. In semi-synthesis, fortified red beet pigment extract was esterified with water-free ethanolic hydrogen chloride solution. The reaction was carried out at ambient temperature (7 days) to yield a mixture of betacyanin mono-, di- and tri-ethyl-esters, and their epimeric forms, as well as the respective betanidin-ethyl-esters. The time course of the reaction mixture was monitored by analytical C18-HPLC with ESI-DAD-MS/MS detection. The detected molecular weights of the pigments confirmed the presence of expected products. To the best of our knowledge, the presence of betalains containing ethyl-ester groups in biological samples have not been studied before.
    Źródło:
    Challenges of Modern Technology; 2014, 5, 3; 27-31
    2082-2863
    2353-4419
    Pojawia się w:
    Challenges of Modern Technology
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Spectrophotometric study on betanin photodegradation
    Autorzy:
    Skopińska, A.
    Tuwalska, D.
    Wybraniec, S.
    Starzak, K.
    Mitka, K.
    Kowalski, P.
    Szaleniec, M.
    Powiązania:
    https://bibliotekanauki.pl/articles/115905.pdf
    Data publikacji:
    2012
    Wydawca:
    Fundacja na Rzecz Młodych Naukowców
    Tematy:
    betanin
    betacyanins
    photodegradation
    Beta vulgaris L.
    Opis:
    The most commonly occurring betacyanin plant pigment in nature is betanin (5-O-glucoside of betanidin). Its main source is red beet root (Beta vulgaris L.), used for production of food colorants on a commercial scale [1]. Due to photo-lability of betacyanins, an eff ect of UV-irradiation on betanin degradation in various solutions containing organic solvents was investigated. Organic solvents are used frequently in many stages of pigment preparation or isolation, therefore, knowledge of betalain stability and degradation characteristics in these solutions is essential. Pigment solutions at a concentration of 1 mg/ml were prepared in diff erent solvents: water as well as aqueous solutions of 50% (v/v) acetonitrile, 50% (v/v) methanol or 50% (v/v) ethanol, at the pH range 3–8. Acetate, phosphate and citrate buff ers were used for the experiments. As a result of the pigment photo-decomposition, numerous decarboxylated and dehydrogenated derivatives were formed. Spectrophotometric studies enabled determination of the pigment retention (percentage of the pigment residue relative to its initial concentration after decomposition time). The studies demonstrated betanin high lability in all solvents, not only at extreme pH values, but also in the middle pH range which, in general, provides higher stability of betalains.
    Źródło:
    Challenges of Modern Technology; 2012, 3, 4; 34-38
    2082-2863
    2353-4419
    Pojawia się w:
    Challenges of Modern Technology
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
      Wyświetlanie 1-5 z 5

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