Betanin and chlorophylls
Betalains are subdivided into red-violet betacyanins and
yellow-orange betaxanthins. Betanin is the most common
betacyanin in the plant kingdom. For a long time beetroot
had been considered the sole source of betanin, and
dehydrated beets (beet powder) is the only betanin-containing
approved color additive in the FDA list [37]. It is
not surprising, therefore, that work on this pigment in
recent years has been dominated by the search for other
sources, such as Ulluco (Ullucus tuberosus), one of the most
widely grown and economically important root crops in
the Andean region of South America [48], and Basella
rubra, commonly known as Malabar spinach, a leafy
vegetable that accumulates pigments in its fruits
[49]. In the latter, total betalain content increased rapidly
from early (green) through intermediate (half-done redviolet)
to matured stage (red-violet). The pigment-rich
fruit extract was used as natural colorant in ice-cream.
After six months of storage at 20 8C, 87% color was
retained in the ice-cream.