Wounding and UVB light synergistically induce the postharvest biosynthesis of indicaxanthin and betanin in red prickly pears
Erika Ortega-Hernández, Vimal Nair, Sayra N. Serrano-Sandoval, Jorge Welti-Chanes, and Daniel A. Jacobo-Velázquez
Postharvest Biology and Technology, Volume 167, September 2020, 111247
2020
บทคัดย่อ
Indicaxanthin and betanin, the main betalains in red prickly pear (Opuntia ficus-indica cv. Rojo vigor), possess important applications as colorants and health-promoting biomolecules. Therefore, it is relevant to explore treatments that induce their postharvest biosynthesis in the fruit. In this study, the effect of ultraviolet B (UVB) radiation and wounding on the biosynthesis of indicaxanthin and betanin in red prickly pear was evaluated. Whole and wounded-fruit (cut in four even pieces with a cross and a longitudinal section) were UVB radiated (6.4โ€ฏWโ€ฏm−2) for 15โ€ฏmin, and stored for 24โ€ฏh at 16โ€ฏ°C. UVB radiation applied in the whole tissue induced an immediate accumulation of indicaxanthin after treatment, obtaining increases of 325.8% and 106.5% in the pulp and peel, respectively. The application of UVB radiation and wounding before storage induced a synergistic effect on the accumulation of indicaxanthin in the pulp (447.0%) and betanin in the peel (315.0%) after storage. Tyrosine hydroxylase and l-dopa oxidase activities of tyrosinase, as well as the spontaneous formation of Cyclo-dopa, which are key steps on betalain biosynthesis, were also synergistically activated by wounding and UVB light. Results allowed the generation of a physiological model explaining the synergistic effect of wounding and UVB on the postharvest biosynthesis of indicaxanthin and betanin in red prickly pear.