Stability of anthocyanins from grape (Vitis vinifera L.) skins with tannic acid in a model system.

摘要

The stability of anthocyanins in nature is thought to be a result of complexing with colourless compounds called copigments. In this study, tannic acid was used as a copigment with the anthocyanin crude extract from Cabernet Sauvignon (Vitis vinifera L.) grapes, and anthocyanin stability was investigated with and without tannic acid addition under different storage conditions in model and beverage systems. Temperature, pH, and presence of light and of oxygen influenced anthocyanin stability. Addition of tannic acid increased the half-life time of anthocyanin in a model system, with similar results to those obtained in the rehydrated beverages. The model system kept a pH 3.0, in the dark, in the presence of nitrogen and at 4 C, had longer half-life times and higher colour retention percentage values.