Varietal Differences in Colorant Properties and Stability of Red Beet Pigments

Samples of 48 beet cultivars were screened for differences in pigment content and stability. Large differences were found between cultivars in betacyanine content and in the proportion of betacyanines and betaxanthines. Extensive variability in pigment content was seen within samples. The thermal stability of betacyanines in diluted beet juice at 100°C was not subject to varietal effects. Differences in betacyanine stability at 25°C between cultivars were significant at the 0.10 level, but not at 0.05. Betacyanines were less stable at pH 3 than at pH 5 and were highly light sensitive. Betaxanthines were similarly affected by pH and light; betaxanthines were much less stable than betacyanines at 25°C.