Abstract

JIMENEZ, Orfa J; MENESES, ErickA; GARCIA, Carlos M  and  DURANGO, Diego L. CHARACTERIZATION OF COLOUR PROPERTIES AND STABILITY OF SOLUTIONS OF PRENYLATED ANTHRANOIDS FERRUGININ A AND ? -HYDROXYFERRUGININ A . Rev.Colomb.Quim. [online]. 2007, vol.36, n.2, pp. 227-242. ISSN 0120-2804.

Colour properties and stability to different factors (temperature and pH) of solutions of prenylated anthranoids ferruginin A (FRA) and ? -hydroxyferruginin A (HFA), obtained from berries of Vismia guianensis and V. baccifera ssp. ferruginea, were evaluated. Spectral characteristics influenced by different temperatures, revealed that the solutions in propylenglycol of the FRA and HFA were relatively stable to the heat to temperatures of the 50 and 80 °C , whereas to temperatures of 100 and 150 °C they displayed slight changes in the intensity ( e ) and tonality ( ? vis-max, colorimetric co-ordinates in the CIE L* a* b* scale). Additionally, colour variation ( ? vis-max, e ) for both anthranoids in the pH range 1.0 - 11.0 during a period of 60 days storage at 4 and 25 °C , showed higher colour stability in refrigerated conditions and pH values of 6.0 and 8.0, being better for solutions of HFA. The good characteristics of compounds make them potentially useful like natural colourants in the textile, cosmetic and pharmacological industry.

Keywords : colour stability; anthranoids; CIE L* a* b*; temperature; pH; natural colourants.