Packaging.
Walnuts are packaged in, among other things, net bags (1.5 - 2.5 kg), polysacks (5 and 10 kg), cartons (10 kg) and flat jute fabric bags (55
kg). Shelled nuts are packaged in, among other things, boxes lined with parchment paper, each containing 12.5 kg (net). Walnut kernels
are ideally stored at a water content of 2 - 3% in packaging which is impermeable to water vapor. Vacuum packaging excludes
atmospheric oxygen, which promotes rancidity.
Transport.
General cargo
Temperature-controlled
Means of transport.
Ship, railroad, truck, aircraft
Container transport.
Ventilated containers (coffee containers), if the lower limits set for the water content of goods, packaging and flooring and the oil
content of the goods are complied with and if protection against solar radiation is ensured (risk of self-heating).
Cargo handling.
In damp weather (rain, snow), the cargo must be protected from moisture, since it may lead to mold, spoilage and self-heating as a
result of increased respiratory activity. No hooks should be used with bagged cargo, so as to prevent damage to the bags and loss of
volume.
Stowage factor.
2.10 m3/t (flat jute fabric bags, 55 kg)
Stowage space requirements.
Cool, dry, good ventilation
Segregation.
Fiber rope, thin fiber nets
Cargo securing.
In order to ensure safe transport, the bags/cartons must be stowed and secured in the means of transport in such a manner that they
cannot slip or shift during transport. Attention must also be paid to stowage patterns which may be required as a result of special
considerations, such as ventilation measures.
In the event of loading as general cargo, dunnage should be used to protect against damage:
•
Floor dunnage: criss-cross dunnage and packing paper
•
Side dunnage: lining with wooden dunnage and mats or jute coverings: protection from metal parts of the ship,
since traces of metal promote cargo rancidity due to autoxidation.
•
Top dunnage: important for voyages to cold regions (winter), since sweat may drip onto the cargo.
Risk factors and loss prevention.
RF Temperature.
Walnuts require particular temperature, humidity/moisture and ventilation conditions (SC VII) (storage climate conditions). For this
reason, precise details should always be obtained from the consignor as to the travel temperature to be maintained.
Designation
Temperature range
Favorable travel
5 - 25° C
temperature range
-3 - 0° C
The stated temperature range of -3 - 0° C is the ideal temperature for achieving the longest possible storage life, but travel temperatures
of 5 - 25° C are feasible, depending upon the duration of the voyage, so this product need not necessarily be carried as chilled goods. It
must, however, be borne in mind that the storage life of the product is correspondingly reduced at temperatures higher than the above
ideal temperature. Temperatures > 30°C must not prevail for a long period, as respiration of the cargo is otherwise promoted. Walnuts
should not be stowed near heat sources (engine room bulkhead, heated tanks).
RF Humidity/Moisture.
Walnuts require particular temperature, humidity/moisture and ventilation conditions (SC VII) (storage climate conditions).
Designation
Humidity/water content
Relative humidity
70%
2 - 8%
Water content
5%
5 - 7%
4 - 5%
Maximum equilibrium
65%
moisture content
Precise details should be obtained from the consignor as to the relative humidity to be maintained during the voyage. Moisture damage
to both unshelled and shelled walnuts occurs under particularly unfavorable conditions, such as direct contact with rain or by dripping
cargo sweat, if the product has not been protected by wooden dunnage, mats or jute coverings. Such protection is also important in
order to minimize the risk of rancidity due to contact between the nuts and metal parts of the ship's hull or of the container.
Nuts which have been wettened by rain may only be accepted once fully dried. Walnuts have the best color and flavor when their water
content is 2 - 8%. A higher water content reduces storage life and increases the risk of rancidity. As is evident from the sorption isotherm
for walnuts, these water contents are at equilibrium with comparatively low relative humidities of up to 73%, i.e. below the mold growth
threshold of 75%. However, the sorption isotherm then rises sharply at higher values, e.g. at 75% relative humidity, the water content of
the walnuts has risen to 14%.
Product information