Application of high-performance liquid chromatography to the characterization of the betalain pigments in prickly pear fruits

The qualitative and quantitative betalain pigment content of two cultivars of prickly pear (Opuntia ficus-indica fruits grown in southeastern Spain wa s evaluated, After methanolic extraction of crushed fruits, reversed-phase high-performance liquid chromatography and photodiode array detection were applied simultaneously for the separation, identification and quantificatio n of these pigments. Two main pigments were obtained, which mere identified as indicaxanthin (lambda (max) 484 nm) and betanin (lambda (max) 535 nm). Spectrophotometric evaluation of both pigments showed a yield of around 20- 30 mg per 100 g of fresh pulp. When the influence of temperature (25 to 90 degreesC) on betacyanin pigment stability was investigated, the results rev ealed a substantial degree of thermodegradation at temperatures higher than 70 degreesC. (C) 2001 Elsevier Science B.V. All rights reserved.