Comparison of stability of red colorants from natural sources, roselle and lac in micelles

Natural colorants have been widely used in food and cosmetic products. Nonionic and anionic surfactants are also usually added as solubilizers and stabilizers in the products. Surfactants form a special structure, a so-called micelle. Micelles can alter stabilities and physicochemical properties of other chemicals in the system. The objectives of this study were to determine stabilities in micellar solutions of extracts from roselle calyx (Hibiscus sabdariffa Linn.) and lac resin (Laccifer lacca Kerr.) providing red colorants. The main constituents of these extracts are two anthocyanins, delphinidin-3-sambubioside and cyanidin-3-sambubioside, and anthraquinones in the form of laccaic acids. The % yields of roselle and lac from the extraction process were 31.96 ± 0.32 and 2.79 ± 0.23, respectively. Roselle colorant faded in the absence and presence of sodium dodecylsulfate (SDS) and Tween80 micelles. The order of stabilities of roselle colorant in solvent systems was buffer ~ Tween80 > SDS. Lac colorant is quite stable in the absence and presence of the surfactants and no significant difference in the % color remaining in the absence and presence of the surfactants was observed.