THE ALLEVIATION OF SAP-INDUCED MANGO SKIN INJURY BY CALCIUM HYDROXIDE
Mango skin injury caused by exuding sap is an important economic problem within the Australian mango industry. Damage is usually associated with the cultivar 'Kensington' which comprises more than 90% of total mango production. Mango fruits were harvested with stems attached and desapped under laboratory conditions. Sap was found to separate into two fractions : an oil (alkenyl resorcinol) and a protein-polysaccharide fraction, the former being responsible for skin injury. Injury occurred wherever the oil fraction made contact with and entered the mango skin via the lenticels. Injury could be largely eliminated by desapping mango fruit immersed in a solution of 1% (w/v) calcium hydroxide. We propose that ionization and subsequent dispersion of the oil fraction occurs under alkaline conditions (pH = 12.5). Bonding may then occur between the ionised fraction of the sap and divalent calcium ions to from a membrane-like polymer on the surface of the solution.
O'Hare, T.J. and Prasad, A. (1992). THE ALLEVIATION OF SAP-INDUCED MANGO SKIN INJURY BY CALCIUM HYDROXIDE. Acta Hortic. 321, 372-381