Physiological age at harvest regulates the variability in postharvest ripening, sensory and nutritional characteristics of mango (#Mangifera indica# L.) cv. Coghshall due to growing conditions
Résumé
BACKGROUND: Climacteric fruits are harvested at the green-mature stage and ripen during their marketing cycle. However, growing conditions induce variability into the maturity stage of mangoes at harvest, with an impact on their final quality. Assuming that the physiological age can be correctly evaluated by a criterion based on the variable chlorophyll fluorescence of the skin (Fv) and that differences in physiological age depend on growing conditions, controlled stress experiments were carried out on mango fruit bymanipulating either the leaf/fruit ratio or the light environment. RESULTS: Delays from 9 to 30 days were observed, depending on stress level and harvest stage, to obtain the same Fv value. For moderate stress, fruit composition after ripening was partially compensated for, with little or no difference in sugar, dry matter, carotenoid and aroma contents. For more pronounced stress, themajor metabolites were not particularly affected, but the synthesis capacity of carotenoids and aromas was lower after maturity. CONCLUSION: The ripening ability of a fruit is acquired on the tree and defines its postharvest changes. Control of the physiological age at harvest can minimise the variability observed under natural conditions and guarantee fruit batches whose postharvest changes will be relatively homogeneous. (Résumé d'auteur)