One of the predominant post harvest problems faced in mangoes is sap injury. The mango fruit has an extensive system of ducts or lactifers in both fruit and stem. Mango sap (latex) sap which is highly acidic in nature is contained within the ducts. In the mature fruit, the sap is under considerable pressure and when the fruit is separated from the stem at the harvest time via an incision, the sap spurts out. This sap is frequently deposited on the surface of the fruits causing browning or blackening of the peel in region of contact with the sap.
Unfortunately sap injury reduces customer acceptance of the fruit even though the mango is perfectly fine and the blemishes are only superficial. The mango connoisseur should be aware that the mango with a sap burn mark is perfectly edible fruit and should not be discriminated. What’s more, even though the physiological role of the mango sap is not exactly know, it probably has a defensive role against disease causing microorganisms and insect pests. Hence the latex is sap like the mango’s natural acid spray for self defense.
We are practicing desapping of the mangoes immediately after harvest to reduce such incidences. However it will not be possible to completely eliminate this phenomenon while using natural organic systems.