Cranberries
| Infobox on Cranberries | |
|---|---|
| Example of Cranberries |  |
| Freshness facts | |
| Optimum carrying temperature | 2°C to 4°C |
| Highest freezing point | -1°C |
| Acceptable product temp. at loading into containers | Max. 2°C above carrying temperature |
| Optimum humidity | 90 to 95% |
| Ventilation setting for containers | 10 m³/hr |
| Storage life | 2 to 4 months |
| Climacteric / non-climacteric | Non-climacteric |
| Ethylene production | Low |
| Ethylene sensitivity | Low |
| Modified / controlled atmosphere | 2%-3% CO2; 1%-2% O2 |
| Potential benefits | Low O2 reduces the respiration rate and retards development of decay. Elevated CO2 helps maintain freshness. CA has not been shown to be effective in extending the storage life of fresh cranberries beyond that possible with conventional cold storage. |
| Availability | |
| Australia Canada South America (Chile) |
On demand September - January April - May |
Cranberries
Contents
Harvesting and handling
Cranberries are closely related to blueberries. They are of particular importance in North America, and a traditional association with certain festivals means that there are brief periods of peak demand for the fresh berries. Much of the crop, however, is processed into a juice and jelly.
Harvesting may be done by hand. However, in some areas a more usual way is to flood the field (or 'bog', as it is usually called) and to harvest mechanically; berries are stripped from the plants by motorised rotating water reels, and the free berries then float until removed from the water by conveyor belts. A disadvantage is the bruising caused by the reels. Furthermore, if the berries cannot be gathered within a few hours of stripping, then subsequent storage decay can reach unacceptable levels.
Cranberries have a low respiration rate, compared with other berry crops which have a moderate to high rate.
The storage-life of cranberries is limited by the development of decay, shrinkage resulting from moisture loss, and physiological breakdown. Early harvested fruit usually have a longer storage potential than late-harvested fruit. Physical damage, which can occur during mechanical or rough hand-harvesting, transport, or mechanical cleaning, sorting and packing, increases physiological breakdown, postharvest softening and decay and reduces storage life.
Fruit red colour intensity, glossiness, uniformity and freedom from defects are the major quality characteristics for fresh and frozen cranberries.
Cooling and storage
The optimum storage temperature of cranberries is between +2ºC and +4ºC, at which they can be kept for 3 to 4 months. Cranberries stored at 0ºC for longer than about 2 weeks are at risk of chilling damage. Low temperature breakdown is characterised by a dull external appearance, and watery or rubbery flesh of a deep maroon colour.
Mixed loads
Can be shipped in mixed loads.
Cautions
Oxygen below 1% can cause off-flavours. Prevention of moisture loss is very important. Keep humidity high.
Storage disorders
Various fungi, Chilling injury, Black rot.