TITLE:
Thermo-Stability of Natural Products Based on Chlorophyll Species Embedded in Silica Xerogel
AUTHORS:
José Martínez-Mendoza, Erika Espericueta-González, Diana Espericueta González, Gerardo Ortega-Zarzosa, Azdrubal Lobo Guerrero
KEYWORDS:
Chlorophyll, Structure, Biostability, Sol-Gel
JOURNAL NAME:
American Journal of Analytical Chemistry,
Vol.7 No.4,
April
20,
2016
ABSTRACT: This work studied
the thermostability and the biostability of chlorophyll species obtained from
an extract of spinach leaves embedded in a silica xerogel matrix. The analysis
was done by monitoring the photosystem II (PSII) using fluorescence
spectroscopy. Samples were prepared using the sol gel method with a molar ratio
of ethanol/H2O/TEOS of 4:11.6:1. Then, silica xerogel matrix was
loaded with an extract of spinach leaves, obtained in dark conditions. The
measurement of the fluorescence spectra was done at selected temperatures to
the corresponding non-physiological regimen. Results indicate that the PSII
band position remains unchanged when heat treatment temperature increases up
200°C. For temperatures above 100?C, the fluorescence intensity diminishes
linearly when the temperature increases. The photosystem II embedded in silica
xerogel matrix is decomposed at temperatures above 200°C.