Papayas

Infobox on Papayas
Example of Papayas
Freshness facts
Optimum carrying temperature	10°C (green) 7°C (turning)
Highest freezing point	-0,9°C
Acceptable product temp. at loading into containers	Max. 2°C above carrying temperature
Optimum humidity	90%
Ventilation setting for containers	25 m³/hr
Storage life	3-4 weeks (green) 2-3 weeks (turning)
Climacteric / non-climacteric	Climacteric
Ethylene production	High
Ethylene sensitivity	High
Modified / controlled atmosphere	5%-8% CO2; 2%-5% O2
Potential benefits	Slight to moderate
Availability
South Africa South America Central America	November - May November-June

Papayas

Harvesting and handling

Papayas are very sensitive sub-tropical fruit, which bruise easily and ripen very fast when exposed to high temperatures. Papayas are climacteric fruits and, for long-distance transport, must be harvested mature green. Judging the correct stage is difficult, and in any batch of harvested fruit there will be a varying range of maturity, some fruits perhaps incapable of normal ripening. Care is necessary during harvesting, to minimise injury and to prevent latex (which oozes out of the cut stem-end) from disfiguring the fruit.

Papayas must be handled very carefully and should be kept dry during all phases of handling and transport. Size, shape, smooth skin, and absence of blemishes are major quality characteristics.

Cooling and storage

For maximum extension of storage life it is advantageous to remove ethylene produced by the fruit itself. The optimal storage temperature is generally given as +7°C for ripe/turning and +10°C for green fruits, if chilling is to be avoided. At these temperatures, green papayas have a PSL (Potential Storage Life) of 3-4 weeks, and turning papayas 2-3 weeks.

The critical temperature, below which chilling injury may occur, is generally considered to be about 7°C for ripe fruits and 10°C for green fruits. Papaya fruit become progressively less susceptible to chilling stress as they ripen. Injury may not be apparent until the fruit is returned to a higher temperature. External signs are small spots, which are dark olive on green fruit and light brown on yellow fruits. They may coalesce to form scald-like areas on the skin. Mild bruises appear more pronounced, and ripening fruits develop a blotchy appearance. Other characteristics include breakdown of the pulp and increased susceptibility to decay, especially Alternaria rot.

Mixed loads

Do not ship with ethylene-producing commodities or ethylene-sensitive commodities.

Cautions

O₂ below 2% for longer than two weeks can cause off-flavours and failure to ripen. CO₂ above 10% can cause off-flavours and may aggravate chilling injury.

Storage disorders

Alternaria rot, Anthracnose, Black rot, Black spot, Blue mould, Chilling injury, Cladosporium rot, Fusarium, Phytophtora, Rhizopus rot, Stem end rot.