Estimating fruit pulp carotenoid content from shell color in gulupa (Passiflora edulis Sims)

• Published in: Ciencia y Tecnología Agropecuaria
• Main Authors: Franco, Germán, Cartagena V., José R, Correa L., Guillermo A
• Format: Journal Article
• Language: Spanish
• Published: Corporación Colombiana de Investigación Agropecuaria (Corpoica) 30.12.2015
• Subjects: Cielab color; Fisiología vegetal; functional foods; tropical fruits; β-carotene
• ISSN: 2500-5308; 0122-8706

Gulupa (Passiflora edulis Sims) is currently receiving increasing acceptance in European markets. However, its short postharvest life constitutes its main marketing limitation, and makes it necessary to characterize its ripening characteristics in order to assure that fruits reaching the consumer are of the best possible quality. Predictive models were fitted to estimate flesh carotenoid content from fruit age and color change. For this purpose, a research was conducted on plant material from the Colombian National Germplasm Bank, administered by Corpoica. Fruit samples of known age were subjected to CIE L* a* and b* space-based colorimetric determination, which confirmed the existence of appreciable color changes since 84 days after flowering (DAF). Deep purple color was reached at around 98 DAF and very dark purple color at 105 DAF. In fruits on the vine, luminosity (L*) was observed to decline, while the value of coordinate a* increased and that of coordinate b* decreased. These changes feature the fruit’s characteristic color. A similar trend was observed in the evolution of color in fruits off the vine (harvested at 91 DAF). In both fruits on and off the vine, carotenoids were found to increase along with fruit age. Two regression models were adjusted to estimate carotenoid content: a multiple model with color coordinates as predictors, and a polynomial model based on fruit age.