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Mango, Magnifera indica / Anacardiaceae
Postharvest Atmosphere Management
Mango
Pre-cooling is applied in order to reduce the temperature of mangoes, particularly the processing by means of hydro-cooling, which facilitates the preservation of mangoes at low temperature before their dispatch. After the hydro-cooling treatment, the temperature of the fruit must have reached 20ºC. Another technique to reduce the temperature of the fruit is forced air, but it is less common than hydro-cooling. If there is no possibility to apply forced air, more than 18 hours will be necessary in cold store rooms or cool transport boxes.

The temperature recommended for cold storage in order to delay maturation is around 7-9ºC for ripe fruit and between 10 and 15ºC for green fruit. At this temperature they may for 2 or 4 weeks. Relative moisture must be around 90 and 95%. At home, mangoes must not be stored in the fridge, but rather in a well ventilated cool place.

Controlled atmosphere, so as to obtain accelerated maturation (5-9 days) and uniformity of the fruit, is achieved with an exposure of 100 ppm of ethylene for 12 to 24 hours at 20-22ºC and 90-95% of relative moisture, depending on the cultivar and the maturation stage. The carbon dioxide concentration in the ripening room must be lower than 1%. The optimal controlled atmosphere is around 3-5% of oxygen and 5-8% of carbon dioxide.

The controlled atmosphere delays maturation and reduces respiration and the rate of ethylene production. The potential post-harvest life oscillates between 2 and 4 weeks at 13ºC in air, and between 3 and 6 weeks in controlled atmosphere, depending on the cultivar and the maturation stage. Actually controlled atmospheres are not used for marketing, although some laboratory trials have proved positive effects.
Distribution
The environmental conditions for preservation are also suitable for the transport and distribution stages.

The recommended transit temperature varies according to the producing areas; between 10 and 13ºC of the low level, the risk of chilling injuries increases.

Long storage, specially at low temperatures, reduces the content of sugar and acid of the fruit. The quality problems are evident after the transport of the fruit by boat, when the period of time between the harvesting and the consumption exceeds 35 days.
Postharvest Problems
Following the harvesting, some problems may arise concerning the rotting of the base of the fruit, chilling injuries, damages caused by bad maturation and post-harvest diseases.

Chilling injuries
Temperatures below 10ºC cause chilling injuries. The most usual symptoms are the appearance of depressed areas of greyish colour, clearly defined and something sunk in the skin, darkening of the pulp, abnormal maturation, greater sensitivity to infections, faster decay, dull colour and taste, as well as the development of spots in the skin.

Damages caused by bad maturation
The suitable temperature for maturation is between 18 and 24ºC. In order to obtain an attractive colour the fruit is stored at 22-24ºC for 2-3 days. Temperatures over 26ºC damage the quality of the fruit, both at an internal level (strong taste) as an external level (mottled skin) with subsequent loss of weight caused by transpiration and greater sensitivity to the development of diseases.

Post-harvest diseases
The main post-harvest disease is anthracnose, whose best treatment is the prevention in the field. In severe cases, the immersion of the fruit in hot water at 54.5-56ºC for 5 minutes may help to control this disease. The effectiveness of this method increases with the use of several fungicides like benomyl, thiabendazone, zineb, diethyldithiocarbamate and borax.

The rotting of the base of the fruit is a serious post-harvest problem. This disease only attacks harvested ripe fruit and it is caused by several fungi whose incidence depends on the production area. The most important are: Lasiodiploidia theobromae, Dothiorella dominicana, Dothiorella mangiferae, Phomopsis mangiferae, Pestalotiopsis mangiferae, Nattrassia mangiferae and Cytosphaera mangiferae.
The symptoms vary depending on the fungus and the fruit maturation. In all the cases, the initial stage is the blackening of the surface around the base of the pedicel . The main difference between this rot and anthracnose is that the infection of the latter does not deepen in the pulp more than 10-20 mm.
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