Difference between revisions of "Artichoke"
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==Harvesting and Handling== | ==Harvesting and Handling== | ||
| − | The artichoke | + | The artichoke is a thistle-like vegetable (edible artichoke) of the composite-flower family. |
<br><br> | <br><br> | ||
| − | The flower heads of the artichoke plant | + | The flower heads of the artichoke plant (growing at the ends of long stalks), reach a diam. of approx. 5 - 15 cm. They consist of a fleshy bottom part and bracts which overlap one another like roof tiles. Only the bottom part and the lower fleshy parts of the bracts are eaten. <br><br>Artichoke colour differs according to variety and ranges from whitish through green to purple. Its slightly bitter flavour (caused by the bitter substance cynarin) and high vitamin content make the artichoke a delicacy. |
<br><br> | <br><br> | ||
Artichokes have to be harvested before the flowers open and the blue petals become visible. A high quality artichoke will have tightly closed, turgid outer bracts without signs of black tip, blistering or browning. They should be medium to dark glossy green in colour and some cultivars may have a magenta colour at the base of each bract. The artichoke should not be soft when squeezed and feel heavy for their size. Both thorny and thornless cultivars are used commercially. | Artichokes have to be harvested before the flowers open and the blue petals become visible. A high quality artichoke will have tightly closed, turgid outer bracts without signs of black tip, blistering or browning. They should be medium to dark glossy green in colour and some cultivars may have a magenta colour at the base of each bract. The artichoke should not be soft when squeezed and feel heavy for their size. Both thorny and thornless cultivars are used commercially. | ||
<br><br> | <br><br> | ||
| − | Open bracts | + | Open bracts indicate that the artichoke is already overripe and quality will quickly degrade. Artichokes in this condition are no longer suitable for long distance transport. Additionally, brown discoloration (of white and green varieties) and dry leaf tips are indicators that the artichokes have been stored for too long and their quality has therefore started to degrade. There should be no water or dew between the individual bracts, as moisture encourages mould growth. |
<br><br> | <br><br> | ||
| − | Because of | + | Because of the considerable impact- and pressure-sensitivity, packages of this produce must be secured in such a way that they cannot damage each other. Spaces between packages or pallets must be filled, to prevent slippage/tipping. Moisture loss can be minimized by cooling adequately and packing artichokes in waxed cartons or in cartons lined with perforated plastic film. |
<br><br> | <br><br> | ||
Splitting of the bract tip is a common problem caused by rough handling during and after harvest. The surfaces of bracts are also easily bruised and scratched. The abraded areas usually turn brown or black, which greatly detracts from appearance and quality, and provide a route through which microorganisms can enter. | Splitting of the bract tip is a common problem caused by rough handling during and after harvest. The surfaces of bracts are also easily bruised and scratched. The abraded areas usually turn brown or black, which greatly detracts from appearance and quality, and provide a route through which microorganisms can enter. | ||
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In order to maintain quality and storage-life, artichoke buds should be pre-cooled to below 5°C within 24 hours of harvest. Hydro-cooling, forced-air cooling and package-icing are common methods of postharvest cooling of artichokes and will generally retard deterioration such as discolouration, weight loss and decay. | In order to maintain quality and storage-life, artichoke buds should be pre-cooled to below 5°C within 24 hours of harvest. Hydro-cooling, forced-air cooling and package-icing are common methods of postharvest cooling of artichokes and will generally retard deterioration such as discolouration, weight loss and decay. | ||
<br><br> | <br><br> | ||
| − | Freezing injury will be initiated at - 1.2°C. Symptoms of light freezing injury are blistering of the cuticle and a bronzing of the outer bracts. This may occur in the field with winter harvested buds and is used in marketing as an index of high quality. More severe freeze injury results in watersoaked bracts and the heart becoming brown to black and gelatinous in appearance over time. | + | Freezing injury will be initiated at - 1.2°C. Symptoms of light freezing injury are blistering of the cuticle and a bronzing of the outer bracts. This may occur in the field with winter harvested buds and is used in marketing as an [[index]] of high quality. More severe freeze injury results in watersoaked bracts and the heart becoming brown to black and gelatinous in appearance over time. |
<br><br> | <br><br> | ||
| − | Artichokes are living organs in which respiration processes predominate, because their supply of new nutrients has been cut off by separation from the parent plant. | + | Artichokes are living organs in which respiration processes predominate, because their supply of new nutrients has been cut off by separation from the parent plant. Respiration processes (release of CO<SUB>2</SUB>, water vapour, ethylene and heat) of the cargo during the voyage must be controlled in such a way that the cargo is at the desired stage of ripeness upon reaching destination. Improper ventilation may result in fermentation and rotting of the produce as a result of increased CO<SUB>2</SUB> levels and inadequate supply of atmospheric oxygen. |
==Mixed loads== | ==Mixed loads== | ||
Revision as of 10:19, 30 May 2012
| Infobox on Artichoke | |
|---|---|
| Example of Artichoke |  |
| Freshness facts | |
| Optimum carrying temperature | 0°C / +1°C |
| Highest freezing point | -1,2°C |
| Acceptable product temp. at loading into containers | Max. 2°C above carrying temperature |
| Optimum humidity | >95% |
| Ventilation setting for containers | 10 m³/hr |
| Storage life | 3-7 weeks |
| Climacteric / non-climacteric | Non-climacteric |
| Ethylene production | Very low |
| Ethylene sensitivity | Low |
| Modified / controlled atmosphere | 2%-3% O2; 2%-5% CO2 |
| Potential benefits | Moderate |
| Availability | |
| Cyprus Egypt France Greece Israel Italy Lebanon Morocco Spain UK |
November - May December - April March - November April - May January - March December - May May - August December - May November - June March - May |
Artichoke
Contents
Harvesting and Handling
The artichoke is a thistle-like vegetable (edible artichoke) of the composite-flower family.
The flower heads of the artichoke plant (growing at the ends of long stalks), reach a diam. of approx. 5 - 15 cm. They consist of a fleshy bottom part and bracts which overlap one another like roof tiles. Only the bottom part and the lower fleshy parts of the bracts are eaten.
Artichoke colour differs according to variety and ranges from whitish through green to purple. Its slightly bitter flavour (caused by the bitter substance cynarin) and high vitamin content make the artichoke a delicacy.
Artichokes have to be harvested before the flowers open and the blue petals become visible. A high quality artichoke will have tightly closed, turgid outer bracts without signs of black tip, blistering or browning. They should be medium to dark glossy green in colour and some cultivars may have a magenta colour at the base of each bract. The artichoke should not be soft when squeezed and feel heavy for their size. Both thorny and thornless cultivars are used commercially.
Open bracts indicate that the artichoke is already overripe and quality will quickly degrade. Artichokes in this condition are no longer suitable for long distance transport. Additionally, brown discoloration (of white and green varieties) and dry leaf tips are indicators that the artichokes have been stored for too long and their quality has therefore started to degrade. There should be no water or dew between the individual bracts, as moisture encourages mould growth.
Because of the considerable impact- and pressure-sensitivity, packages of this produce must be secured in such a way that they cannot damage each other. Spaces between packages or pallets must be filled, to prevent slippage/tipping. Moisture loss can be minimized by cooling adequately and packing artichokes in waxed cartons or in cartons lined with perforated plastic film.
Splitting of the bract tip is a common problem caused by rough handling during and after harvest. The surfaces of bracts are also easily bruised and scratched. The abraded areas usually turn brown or black, which greatly detracts from appearance and quality, and provide a route through which microorganisms can enter.
Cooling and Storage
In order to maintain quality and storage-life, artichoke buds should be pre-cooled to below 5°C within 24 hours of harvest. Hydro-cooling, forced-air cooling and package-icing are common methods of postharvest cooling of artichokes and will generally retard deterioration such as discolouration, weight loss and decay.
Freezing injury will be initiated at - 1.2°C. Symptoms of light freezing injury are blistering of the cuticle and a bronzing of the outer bracts. This may occur in the field with winter harvested buds and is used in marketing as an index of high quality. More severe freeze injury results in watersoaked bracts and the heart becoming brown to black and gelatinous in appearance over time.
Artichokes are living organs in which respiration processes predominate, because their supply of new nutrients has been cut off by separation from the parent plant. Respiration processes (release of CO2, water vapour, ethylene and heat) of the cargo during the voyage must be controlled in such a way that the cargo is at the desired stage of ripeness upon reaching destination. Improper ventilation may result in fermentation and rotting of the produce as a result of increased CO2 levels and inadequate supply of atmospheric oxygen.
Mixed loads
Artichokes can be shipped in mixed loads at 0° to 5°C for durations shorter than two weeks.
Controlled atmosphere considerations
Controlled or modified atmospheres show moderate to little benefit to sustaining artichoke quality when stored at 0°C. Conditions of 2%-3% O2 and 2%-5% CO2 delay discolouration of bracts and the onset of decay by a few days at temperatures around 5°C. Atmospheres below 2% O2 may result in internal blackening of artichokes. However, in most cases, low temperature and high humidity (>95%) will ensure better quality than use of CA/MA.
Storage disorders
Bacterial rots, Blackening, Downy mildew, Chilling injury, Grey mould rot, Powdery mildew.