Color and pigment stability of red radish and red-fleshed potato anthocyanins in juice model systems

Color and pigment stability of model juices (pH 3.5) were evaluated during 65 wk of storage at 2 degrees C and 25 degrees C in the dark. Two acylated pelargonidin-based anthocyanins, red-fleshed potatoes (Solanum tuberosum) and red radishes (Raphanus sativus), and 2 extraction methods, C-18 resin and juice processing, were used and compared to FD&C Red #40. Color (CIELch) and pigment degradation depended on storage temperature, anthocyanin structure and extraction method, with chemically extracted radish anthocyanins showing the best overall stability. At room temperature (25 degrees C), higher stability was obtained with C-18 purified radish anthocyanins (22 wk half-life) and lowest with potato juice concentrate (10 wk half life). Refrigeration increased the half-life of pigments to over a year.