Stability of Anthocyanin- Copigment Complex under the Effect of Copigment Concentration in Black Dezfuly Mulberry in Sanandaj

In these study the anthocyanin pigment was extracted from the black dezfuly mulberry in Sanandaj using the soaking in ethanol. Then copigmentation of anthocyanin pigments were investigated with four copigments, tannic acid, coumaric acid, benzoic acid and caffeic acid. In this research, the dependence of the copigmentation process on the copigment concentration was established. Five levels of copigment concentration as: 1: 0, 1: 120, 1: 240, 1:480, 1: 960 and four different pHs (1, 2, 3.5 and 4.5) were examined. Copigmentation of anthocyanin resulted in the increase of both hyperchromic effects and bathochromic shifts. In this study, coumaric acid has the highest hyperchromic effect, and tannic acid has the lowest hyperchromic effect. Coumaric acid was the best copigment for mulberry anthocyanin and tannic acid seem to be rather poor copigment in contrast with other acids. The copigmentation effect increased with copigment contained. In all of anthocyanin-copigment complex the highest anthocyanin-copigment molar ratio of 1:960 resulted in the strongest copigmentation effect.

Keywords:

colour , anthocyanin , stability , copigmentation , mulberry