PROCESS FOR PREPARING NATURAL ANTHOCYAN DYE Russian patent published in 1994 - IPC

FIELD: food-processing industry. SUBSTANCE: black-ashberry residues are subjected to freezing, coloring constituents are extracted in hot water with addition of citric acid. The resulting coloring extractive solution is evaporated in vacuum to remove water. The resulting concentrate is treated with methyl iodide and kept at room temperature under stirring. The thus-modified dye formed in a day is recovered by separating colored phases from colorless bottom layer. EFFECT: increased dying stability. 1 tbl