Stability and Color of Unreported Wine Anthocyanin‐derived Pigments

Abstract

Grape anthocyanin-3-glucosides and unreported natural pigments characterized as vinylphenol anthocyanin-3-glucoside adducts were studied. Our investigations were undertaken to compare color and stabilities when processed and stored under identical conditions. Studies of molecular concentration, color density and Hunter color values were done at pH levels. Grape anthocyanin-3-glucosides were less stable than their 4-vinylphenol derivatives and the color stability of the unreported pigments was higher than that of anthocyanin-3-glucosides. Moreover, the compounds were resistant to SO 2 discoloration whereas anthocyanins were completely bleached.

Colour stability of anthocyanins from Isabel grapes (Vitis labrusca L.) in model systems

“…This result is in agreement with the research realized by Sarni-Manchado, Fulcrand, Souquet, Cheynier, and Moutonet (1996) who verified that the presence of light implicated significant loss in the colour of anthocyanins from Vitis vinifera L. grapes (Granache Noir varietal). The addition of tannic acid to the anthocyanins was significantly influenced by the presence of light.…”

Stability of anthocyanins extracted from grape skins

“…The anthocyanins were eluted under the following conditions: flow rate, 1 mL.min 1; oven, 30 ~ solvent A, 20mL.L 1 formic acid in water; solvent B, acetonitrile-water-formic acid (80:18:2, v/v/v); elution with linear gradients from 5% to 30% B in 40 min, from 30% to 50% B in 20 min, from 50% to 80% B in 10 min, following by washing and reconditioning the column [10]. The detection wavelength was 250 600 nm.…”

Pigments in Grape

“…Tannin-anthocyanin adducts are red, like their anthocyanin precursors ( λ max 515-526 nm). Other reaction products include orange pyranoanthocyanins ( λ max 480-510 nm) [25,26], purple ethyl-linked species (λ max 528-540 nm) [18,27], and blue flavanyl-vinylpyranoanthocyanins (λ max 575 nm) [28]. These compounds may also change colors with the alternation of pH.…”