A "green" extraction protocol to recover red pigments from hot capsicum fruit

Abstract

Plant pigments represent a source of non-toxic compounds that are used as food or cosmetic coloring agents. Red-fruited varieties of Capsicum annuum can be extracted to isolate the red-colored xanthophylls, capsanthin, and capsorubin. Common commercial processes for this extraction use hexane as the extracting solvent and mild or no heat varieties of Capsicum. In this report, we describe a process for efficient extraction of these red pigments using green chemistry: CO2 supercritical fluid extraction and trapping the pigments in ethanol. Furthermore, we demonstrate that this method can be performed on hot or pungent Capsicum fruit and the resulting pigment sample has very low levels of capsaicinoids, 1 to 2 ppm. This process then can reduce the use of hazardous solvents and expand the type of fruit that can be used for the extraction of red pigments.