Enhancing the light fastness of natural dyes by encapsulation in silica matrix

The study shows the possibility of improving the light fastness of natural curcumin dyes extracted from turmeric by encapsulation in silica matrix. Curcumin extracts were obtained by conventional and microwave assisted extractions. Encapsulation into a silica matrix was performed by using three different routes in the presence of NaOH, lysine or triethanol amine. The curcumin loaded silica particles were characterized by SEM, EDX, FT-IR, UV–Vis and photoluminescence spectroscopy analyses. The light fastness of the curcumin capsules was further investigated by UV–Vis spectroscopy. The color description was performed by employing the CIEL*a*b* system and the color difference was calculated. The stabilization methods lead to high encapsulation efficiencies and a very good light fastness for all samples.