| Autor: |
Yoon, J.-M., Cho, M.-H., Park, J.-E., Kim, Y.-H., Hahn, T.-R., Paik, Y.-S. |
| Předmět: |
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| Zdroj: |
Journal of Food Science (Wiley-Blackwell); Apr2003, Vol. 68 Issue 3, p839-843, 5p |
| Abstrakt: |
Three major yellow pigments were isolated from safflower petals (Carthamus tinctorius) and characterized as hydroxysafflor yellow A (1), safflor yellow B (2), and precarthamin (3) by 1H-NMR, 1H-1H COSY, 13CNMR, HMQC, and HMBC spectral analysis. Thermal degradation reactions of 3 yellow pigments 1 to 3 at temperatures of 70 to 90 °C were carried out at different pH levels within the range of 3.0 to 10.0 by UV-vis spectral measurements. First-order reaction kinetics was observed for the degradation of safflower yellow pigments (1 to 3) at pH 3.0 and 5.0. Activation energies of thermal degradation of 1-3 at pH 5.0 were calculated as 17.0, 15.4, and 20.1 kcal/mol, respectively. At neutral and alkaline conditions, yellow pigments 1-3 did not follow simple first-order kinetics. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
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