STABILITY OF BETALAIN PIGMENTS FROM A CACTACEA FRUIT

The garambullo tree (Myrtillocactus geometrizans) which grows in the d eserts of Mexico produces a purple fruit. The pigments were extracted, identified, and evaluated for their stability at different temperatur es and pH values and in the presence of iron and chromium. One percent citric acid or ascorbic acid was added as a stabilizer, and a mixture of both was also used. On the basis of their visible Light spectrum a nd chromatographic profile, the pigments were identified as betalains, which have a stability greater than that of red beet pigments and whi ch are very stable at low temperatures. The pigment concentration was determined to be 214 mg/(100 g of dry weight). The energy of activatio n for bleaching of color was 87.09 +/- 8.53 J K-1 mol(-1) at pH 5.5. A scorbic acid protects the red color even when it is exposed to drastic treatments such as sterilization. Metals decrease the stability of ga rambullo pigment; the effect of iron was greater than that of chromium . Garambullo pigment has the potential for use in food processing at l ow temperatures such as in the dairy industry for the production of ic e cream and dairy drinks.