Year: 2025
Type: article
Abstract: This study investigates effective antioxidants to stabilize chlorophyll, a valuable and most abundant but unstable natural green pigment, adsorbed on a silica surface. Although fixing chlorophyll on silica offers some protection, significant photo-induced oxidative degradation still occurs. To enhance photostability, the prepared chlorophyll–silica composites were combined with various well-known antioxidants. The stability of these samples was evaluated by the deterioration ratio of the chlorophyll under visible light irradiation. The results showed that gallic acid provided the most significant stabilization effect. This was attributed to its moderate hydrophilicity, allowing it to be positioned near the chromophore part of the chlorophyll molecule adsorbed on the silica surface. Further tests with the derivatives of gallic acid revealed that smaller molecular size and less steric hindrance were also crucial for effectiveness as an antioxidative stabilizer. Pyrogallol and gallic acid, being the smallest molecules, performed best. It was concluded that the ability of an antioxidant to approach a chlorophyll molecule is essential for stabilization. This requires an appropriate balance of hydrophilicity and a small molecular size. Considering the nontoxicity together, gallic acid is recommended as a superior stabilizer for chlorophyll on silica surfaces.
Source: Colorants
Authors: Yoshiumi Kohno, Rika Fukagawa, Masashi Shibata, Yasumasa Tomita
Institutions: Shizuoka University, Tokyo University of Technology
Language: English
Subfield: Materials Chemistry
Field: Materials Science
Domain: Physical Sciences
Open Access status: gold
Estimated APC paid: $1,207
OpenAlex ID: W4415351236