Filters

2018 - 20202

More filters

2021 - 20232
Reset filters

Settings

Type: Article × Subject: pigments ×

Search Results

Now showing 1 - 2 of 2
  • Thumbnail Image
    Item
    Optimisation of O2 and CO2 concentrations to retain quality and prolong shelf life of ‘shelly’ mango fruit using a simplex lattice mixture design
    (San Diego, Calif. : Academ. Press, 2020) Ntsoane, Makgafele L.; Sivakumar, Dharini; Mahajan, Pramod V.
    The experimental design and gas mixture selection is of great importance in the definition of optimal gas concentrations for use in storage of fresh produce. The aim of this study was to optimise O2 and CO2 concentrations under controlled atmosphere conditions to understand the effect on quality and shelf life of ‘Shelly’ mango fruit stored at 13 °C for 28 d. This was achieved by designing three experimental points (gas compositions = O2, CO2 and N2) using simplex lattice mixture design to (i) determine single and interaction effects of gas compositions on selected quality parameters and (ii) determine the optimal gas combination in order to maintain quality and prolonging shelf life of ‘Shelly’ mango fruit. The estimated model parameters coefficients successfully categorised the single and interaction effects of O2, CO2 and N2 gas compositions. The selected quality attributes experimental data was fitted well using the canonical Scheffe type special cubic model, resulting in coefficient of Determination, R2 = 0.70 to 0.97. The low O2 and high CO2 in CA-2 managed to retard ripening and mass loss, and reduce fruit softening and chlorophyll degradation. Positive relationship was observed for linear effect in all quality attributes, while binary and ternary interaction effects varied across all the treatments. The optimal gas compositions for storage of ‘Shelly’ mango fruit in terms of selected quality attributes ranged between 5 and 8% O2 + 5–9% CO2 + 86–91% N2. The results highlight the potential use of simplex lattice mixture design to optimise CA storage conditions.
  • Thumbnail Image
    Item
    Characterization of Zahari Zograph’s nave wall paintings in the church “The nativity of the virgin” of Rila Monastery (Bulgaria) by vibrational spectroscopy and SEM–EDX analysis
    (Abingdon, Oxon : Routledge, Taylor and Francis Group, 2018) Yancheva, Denitsa; Tapanov, Stefan; Velcheva, Evelina; Stamboliyska, Bistra; Glavcheva, Zornitza; Stoyanov, Simeon; Haralampiev, Nikifor; Fischer, Dieter; Lederer, Albena
    An analytical study on the nave mural paintings of the church “The Nativity of the Virgin” of Rila monastery, Bulgaria, painted by Zahari Zograph was carried out. Vibrational spectroscopy was applied to identify the pigments and organic materials used in the mural paintings. To complement the spectral information, elemental composition of the samples was determined by SEM-EDX. The data showed that smalt with carbohydrate binder was applied for the blue background, green colour was executed by green earths and red-orange colour – by red lead. Azurite is the pigment used to paint the blue colour of the saints’ hoods. The mordant for gilding was prepared of drying oil, resin and siccative metal oxides as evidenced by SEM-EDX, ATR-FTIR and pyrolysis GC-MS analysis. The use of azurite is related to Zahari Zograph’s works as it was not found in any of the previously studied murals in the church painted by other artists.