Cucumbers

Infobox on Cucumbers
Example of Cucumbers	240px
Freshness facts
Optimum carrying temperature	10°C to 12°C
Highest freezing point	-0,5°C
Acceptable product temp. at loading into containers	Max. 2°C above carrying temperature
Optimum humidity	95%
Ventilation setting for containers	25 m³/hr
Storage life	1 to 2 weeks
Climacteric / non-climacteric	Non-climacteric
Ethylene production	Low
Ethylene sensitivity	High
Modified / controlled atmosphere	3% - 5% O2; 5% - 7% CO2
Potential benefits	Slight
Availability
On demand

Cucumbers

Harvesting and Handling

Cucumbers have juicy, fibrous flesh. Due to its subtropical origins, the cucumber's heat requirements are high and it is therefore cultivated predominantly as a greenhouse product.

There are two principal varieties, distinguished by their manner of cultivation:

Slicing cucumbers, snake cucumbers:

These are cultivated in greenhouses and poly-tunnels and are therefore largely unaffected by external weather conditions, making them suitable for cultivation virtually anywhere in the world. They are approx. 40 cm long, reach a diameter of 10 cm and are smooth-skinned.

Pickling cucumbers:

These are outdoor-grown and therefore have particular climatic requirements. They are sometimes only a few cm long, but may grow as long as 20 cm, and are thick and rough-skinned.

When unripe, cucumbers are green-coloured. As they ripen, they turn yellowish-white or yellowish-brown. Modern cucumbers are basically free from bitter substances. However, the bitter substance elaterin may sometimes form in pickling cucumbers in particular, where it may be present in particularly large quantities at the stem-end.

Cucumbers should be green, smooth and as seedless as possible. Yellowness of the skin indicates over-ripeness. Cucumbers in this condition are no longer suitable for transport. Cucumbers should also be clean and undamaged, to prevent quality degradation during transport.

Cucumbers are packaged in various ways, including in strong cartons of corrugated board with plastic film lining. The sides of the cartons are reinforced and provided with perforations. The individual cucumbers are often heat-sealed in gas-permeable plastic film, which extends storage life, minimizes evaporation and weight-loss

Cooling and Storage

Recommended conditions for commercial storage of cucumbers are 10 to 12°C. Storage-life is generally <14 days, with visual and sensory quality rapidly declining thereafter.

Cucumbers are very susceptible to physiological chilling damage, which occurs at temperatures <10°C. Chilling damage manifests itself initially in soft, water-soaked, easily depressed spots on the skin; this is later followed by the discharge of liquid and detachment of the epidermal layers. Affected cucumbers rapidly become glassy and tasteless. A bacterial and/or fungal secondary infection may occur at the injured points.

Travel temperatures higher than approx. 12°C reduce the storage life of the cargo, causing the cucumbers to turn yellow, so making them unsaleable.

Controlled atmosphere considerations

Little benefit is realized from the CA storage of cucumber fruit. Cucumbers produce very little ethylene but are sensitive to the effects of ambient ethylene which causes rapid yellowing.

Storage disorders

Alternaria rot, Anthracnose, Bacterial rots, Black spot, Blue mould, Cladosporium rot, Cottony leak, Fusarium solani, Insect damage, Phytophthora, Sour rot, Watery soft rot.