Harvest maturity and concentration and exposure time to acetylene influence initiation of ripening in mangoes.
Medlicott A. P., N'Diaye M., Sigrist J. M. M.
Author Affiliation: Overseas Development & Natural Resources Institute, London WC1X 8LU, UK.
Journal of the American Society for Horticultural Science 115 : 426-430
Abstract : The effects of acetylene at 0, 0.1, 0.2, 0.4, 0.8 or 1.6 ml/litre and exposures of 4, 8, 12 or 24 h on ripening initiation in mangoes harvested at 3 stages of maturity were investigated over 2 successive seasons in Brazil. Ripeness was assessed before and after treatment in Tommy Atkins, Ruby and Amelie fruits by analysis of texture, peel and pulp colour development, soluble solids concentration, and pH. The initiation of ripening depended on the acetylene concentration, exposure time to acetylene, the physiological maturity of the fruit at harvest, and on the cultivar. Changes that can occur during ripening had different sensitivities to acetylene gas. Acetylene treatment of 0.1 or 0.2 ml/litre for 24 h at 25°C initiated softening, but had no effect on the other ripening processes measured. All the ripening changes measured were initiated with a 24-h exposure to 0.4 ml/litre in Tommy Atkins, while 0.8 ml/litre was required with Ruby. There was an interaction between gas concentration and exposure time taken to initiate ripening. The 0.8 ml/litre acetylene treatment required 24 h to initiate full ripening, while 8 h were required with 1.6 ml/litre acetylene and 1.0 ml/litre ethylene. Mature and half-mature fruits showed a similar response to gas treatments; immature fruits failed to show full ripening initiation, although softening and peel colour development were enhanced.