Antioxidant activities of sicilian prickly pear (Opuntia ficus indica) fruit extracts and reducing properties of its betalains: Betanin and indicaxanthin

Daniela Butera, Luisa Tesoriere, Francesca Di Gaudio, Antonino Bongiorno, Mario Allegra, Anna Maria Pintaudi, Rohn Kohen, Maria A. Livrea*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

476 Scopus citations


Sicilian cultivars of prickly pear (Opuntia ficus indica) produce yellow, red, and white fruits, due to the combination of two betalain pigments, the purple-red betanin and the yellow-orange indicaxanthin. The betalain distribution in the three cultivars and the antioxidant activities of methanolic extracts from edible pulp were investigated. In addition, the reducing capacity of purified betanin and indicaxanthin was measured. According to a spectrophotometric analysis, the yellow cultivar exhibited the highest amount of betalains, followed by the red and white ones. Indicaxanthin accounted for about 99% of betalains in the white fruit, while the ratio of betanin to indicaxanthin varied from 1:8 (w:w) in the yellow fruit to 2:1 (w:w) in the red one. Polyphenol pigments were negligible components only in the red fruit. When measured as 6-hydroxy-2,5,7,8-tetramethylchroman-2-carboxylic acid (Trolox) equivalents per gram of pulp, the methanolic fruit extracts showed a marked antioxidant activity. Vitamin C did not account for more than 40% of the measured activity. In addition, the extracts dose-dependently inhibited the organic hydroperoxide-stimulated red cell membrane lipid oxidation, as well as the metal-dependent and -independent low-density lipoprotein oxidation. The extract from the white fruit showed the highest protection in all models of lipid oxidation. Purified betanin and indicaxanthin were more effective than Trolox at scavenging the [2,2′-azinobis(3-ethylbenzothiazoline-6-sulfonic acid)] diammonium salt cation radical. Cyclic voltammetric measurements show two anodic waves for betanin and indicaxanthin, and differential pulse voltammetry shows three anodic waves for betanin, with calculated peak potentials of 404, 616, and 998 mV, and two anodic waves for indicaxanthin, with peak potentials of 611 and 895 mV. Betanin underwent complex formation through chelation with Cu2+, whereas indicaxanthin was not modified. These findings suggest that the above betalains contribute to the antioxidant activity of prickly pear fruits.

Original languageAmerican English
Pages (from-to)6895-6901
Number of pages7
JournalJournal of Agricultural and Food Chemistry
Issue number23
StatePublished - 6 Nov 2002

Bibliographical note

Funding Information:
Acknowledgments The authors wish to thank Fundação para a Ciência e Tecnologia for financial support through the Praxis/P/QUI/10109/1998 project and ATRAL Cipan for the potassium clavulanate samples provided. One of the authors (A.M.P.) wishes to thank the Praxis Program for the Ph.D. grant (Praxis/BD/19793/99).


  • Betalains
  • Betanin
  • Indicaxanthin
  • Low-density lipoprotein
  • Natural antioxidants
  • Prickly pear


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