1. Álvarez, M. J. M., Medina, C., Anton, L., García, D., & Camacho, D. R. B. (2003). Uso de pulpa de tuna (Opuntia boldinghii) en bebidas cítricas pigmentadas. Interciencia, 28(9), 539–543.
2. Azeredo, H. M. C. (2009). Betalains: Properties, sources, applications, and stability—a review. International Journal of Food Science and Technology, 44(12), 2365–2376.
3. Bourhia, M., Elmahdaoui, H., Moussa, S. I., Ullah, R., & Bari, A. (2020). Potential natural dyes food from the powder of prickly pear fruit peels (Opuntia spp.) growing in the Mediterranean Basin under climate stress. Biomed Research International, 2020, 9.
4. Bratinova, S. (2015). Provision of scientific and technical support with respect to the classification of extracts/concentrates with colouring properties either as food colours (food additives falling under Regulation (EC) No 1333/2008) or colouring foods.EU, P. O. o. t.
5. Buchweitz, M., Brauch, J., Carle, R., & Kammerer, D. R. (2013). Application of ferric anthocyanin chelates as natural blue food colorants in polysaccharide and gelatin based gels. Food Research International, 51(1), 274–282.