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Wyświetlanie 1-2 z 2
Tytuł:
Antioxidant Properties and Stability of Geissospermum Reticulatum Tinctures: Lag Phase ESR and Chemometric Analysis
Autorzy:
Sajkowska-Kozielewicz, J.J.
Gulik, K.
Makarova, K.
Paradowska, K.
Powiązania:
https://bibliotekanauki.pl/articles/1032448.pdf
Data publikacji:
2017-07
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
07.05.Mh
87.64.kh
87.80.Lg
Opis:
Geissospermum species are widely used in folk medicine in the Amazon region. This study was conducted to determine total phenolic and flavonoid contents of three tinctures of Geissospermum reticulatum barks from Peruvian Amazon and correlate these contents to the antioxidant activities and stability. Total content of phenolic compounds (from 694.91 to 1430.67 mg GAE/kg) and flavonoids (575.23-815.65 mg CAE/kg) were found by spectrophotometric methods. The obtained values were interpreted by artificial neural networks to describe the most beneficial conditions for tinctures. All tinctures have demonstrated the maximum of total flavonoid between 14 and 20 weeks of maceration, whereas the maximum of total flavonoid was between 25 and 30. The highest antioxidant properties were exhibited by tinctures in 3 different tests (ferric reducing ability of plasma, DPPH-ESR, oxygen radical absorbance capacity) after 35 weeks of maceration. The principal component analysis was employed to relate contents and properties. Results from the lag phase with α -(4-pyridyl-1-oxide)-N-tert-butylnitrone (POBN) spin trap studies at 60°C demonstrated that the stability of tinctures were related to total phenolic content. Thus, samples with 550-800 mg GAE/kg were more stable than those with higher total phenolic contents. The most beneficial conditions for bark tinctures depend on aimed final products, e.g. maximum of polyphenols or flavonoids and long-term stability. Further studies about content and storage conditions are needed.
Źródło:
Acta Physica Polonica A; 2017, 132, 1; 68-73
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Optimization of Antioxidant Properties of Creams with Berry Extracts by Artificial Neural Networks
Autorzy:
Makarova, K.
Zawada, K.
Wagner, D.
Skowyra, J.
Powiązania:
https://bibliotekanauki.pl/articles/1030222.pdf
Data publikacji:
2017-07
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
07.05.Mh
33.35.+r
61.72.Hh
76.30.-v
87.64.kh
87.80.Lg
Opis:
Oxidative stress and the excess of free radicals accelerate the ageing process of human skin. The application of skin cream with antioxidant compounds could reduce the damage caused by free radicals. In this work we studied two types of skin creams with extracts from aronia (Aronia melanocarpa), elderberry (Sambucus nigra) and bilberry (Vaccinium myrtillus) because of their high content of anthocyanins, i.e. strong natural antioxidants. The 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging ability of the skin creams with berry extracts were studied with ESR spectroscopy. The artificial neural networks were applied to optimize the berry extract concentration and storage time for oil-in-water and water-in-oil creams. Based on experimental results chokeberry and elderberry extracts in oil-in-water cream base revealed higher DPPH radical scavenging ability than in the corresponding water-in-oil. Artificial neural networks predicts maxima of DPPH radical scavenging for 1-week stored elderberry (2.23 mg DPPH/g) and 1-week stored chokeberry (5.84 mg DPPH/g) and bilberry (5.26 mg DPPH/g) 0.76% extracts in oil-in-water creams. The maxima of DPPH radical scavenging for water-in-oil creams were predicted for 6-week stored 0.8% aronia extract, freshly prepared 0.76% bilberry extract and 1-week stored 0.56% elderberry extract. The artificial neural networks predicted values are in good agreement with the experimental values. DPPH-EPR could be combined with artificial neural networks to optimize the extract concentration, and the type of cream base as well as to predict the effect of storage based on a limited number of experiments and samples.
Źródło:
Acta Physica Polonica A; 2017, 132, 1; 44-51
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
    Wyświetlanie 1-2 z 2

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