Stability of betalain pigments from a cactacea fruit.

摘要

The garambullo tree, Myrtillocactus geometrizans, grows in the deserts of Mexico and produces edible purple fruits. The pigments, extracted from fruits (collected from Queretaro valley, Mexico), were identified and evaluated for their stability at different temperatures and pHs and in the presence of Fe or Cr. Citric and/or ascorbic acid (1%) were added as stabilizers. On the basis of their visible light spectrum and chromatographic profile, the pigments were identified as betalains. These pigmentswere more stable than beetroot pigments and were very stable at low temperatures. Betalain concentration of fruits was 214 mg/100 g (dry weight). The energy of activation for bleaching of colour was 87.09±8.53 J K-1 mol-1 at pH 5.5. Ascorbic acid protected the red colour. Metal ions decreased the stability of garambullo pigment; the effect of Fe was greater than that of Cr. It was concluded that garambullo pigment has potential for use in food processing at low temperatures such as in the dairy industry for the production of ice cream and dairy drinks.