Stabilization of Flavylium Dye by Incorporation into Bentonite Clay

摘要

We have enhanced the stability of a flavylium dye, a model compound of a natural anthocyanin dye, by the incorporation into the interlayer of a natural clay, bentonite. The composite of the flavylium and the bentonite shows excellent stability under increased temperature (up to 353 K) or alkaline environment (pH ～ 9) compared to the original flavylium dyes. This material can be candidate of an environmentally friendly coloring material. Increased amount of dye causes a muddy color due to the formation of dye aggregate. Samples with brilliant color can be obtained with the loading amount less than 0.25 mmol dye per g-clay.