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Pistachio nuts require particular temperature,
humidity/moisture and ventilation conditions for this reason, precise details
should always be obtained from the consignor as to the travel temperature to be
maintained. The stated travel temperature of
0°C is the ideal temperature for achieving the longest possible storage life,
but higher travel temperatures (5 - 25°C) are feasible (depending upon the
duration of the voyage), so this product need not necessarily be carried as chilled
goods. Temperatures > 30°C should not prevail
for a long period, as respiration of the cargo is otherwise promoted. Pistachio
nuts should not be stowed near heat sources (engine room bulkhead, heated tanks).
Above all, they must not be exposed to sunlight, as these results in impaired
flavor. Pistachio nuts require particular temperature,
humidity/moisture and ventilation conditions
| Designation | Humidity/water
content | Source |
| Relative humidity | 65 - 70% | [1]
| | Water
content | 6% | [1] |
| | 4% | [2] |
| | 6% | [5]
| | Maximum
equilibrium moisture content | 65% | [1] |
Precise details should be obtained from
the consignor as to the relative humidity to be maintained during the voyage. Pistachio
nuts must be protected from all forms of moisture (seawater, rain and condensation
water), since there is otherwise an increased risk of mold, rot and rancidity.
They rapidly absorb moisture from the air and the flavor becomes insipid. Sodden
packing drums or bags must be rejected as seawater, rain and condensation water
Promote hydrolytic/enzymatic fat cleavage,
which leads to self-heating as a result of increased respiration. Pistachio nuts require particular temperature,
humidity/moisture and ventilation conditions. Recommended
ventilation conditions: air exchange rate: at least 10 changes/hour (airing) Pistachio nuts display 2nd
order They are living organs in which respiration
processes predominate, because their supply of new nutrients has been cut off
by separation from the parent plant. Care of the cargo
during the voyage must be aimed at keeping decomposition processes at the lowest
possible level, so as to keep within limits any losses in quality caused by the
emission of CO2, heat and water vapor. In pistachio nuts (particularly when fresh),
metabolic processes continue even after harvesting. They absorb oxygen and excrete
carbon dioxide (CO2). If ventilation has been inadequate
(frost) or has failed owing to a defect, life-threatening CO2 concentrations or
O2 shortages may arise. Therefore, before anybody enters the hold, it must be
ventilated and a gas measurement carried out. The TLV for CO2 concentration is
0.49 vol. %. Oil content:
45 - 54% [1] 55% [2] Because of their tendency to self-heating, pistachio
nuts may behave like substances from Class 4.2 of the IMDG Code. Excessive
stack pressure results in self-heating. Oils which have accumulated in the jute
packaging fabric encourage this behavior. Pistachio
nuts, especially pistachio kernels, should not be stowed together with fibers/fibrous
materials as oil-soaked fibers may promote self-heating/spontaneous combustion
of the cargo. As a basic principle, high oil content
(especially in pistachio kernels) encourages the tendency to self-heating. Fat
decomposition in pistachio nuts leads to the risk of self-heating and, ultimately,
to a cargo fire. Fat decomposition may proceed as
follows: by hydrolytic/enzymatic fat cleavage or by
oxidative fat cleavage If the critical
water content of the pistachio nuts is exceeded, this promotes hydrolytic/enzymatic
fat cleavage. Fat-cleaving enzymes are activated by the elevated water content.
The additional action of light and heat may accelerate this process. Free fatty
acids sometimes have an unpleasant odor and taste. In the event of extended storage
or improper cargo care, these cause the cargo to become rancid. The
free fatty acids formed are consumed by respiration processes in the pistachio
nuts to form carbon dioxide and water, a process which is associated with considerable
evolution of heat. Self-heating of pistachio nuts
is an extremely vigorous process, as the consumption of fatty acids by respiration
processes is associated with a considerably greater evolution of heat than is
the case with the respiration equation for carbohydrates. Here too, as with
cereals, the spoilage process proceeds in a type of chain reaction, because heat
and water are formed by the fatty acids consumed by respiration, which in turn
contribute to an intensification of the process. The
self-heating of pistachio nuts requires only a small seat of moisture, so that
within just a few hours heating may occur at moist points for which weeks or months
would be required in goods dry on shipment. Fresh
pistachio nuts with high water content tend in particular towards rapid self-heating
and may also ignite. Self-heating of pistachio nuts leads not only to a reduction
in the utility value of this product (rancid odor and taste) but also has a qualitative
and quantitative effect on oil yield. The color and bleach ability of the
oils are also negatively affected. The oil obtained complicates refining of the
crude oils in subsequent processing, because higher free fatty acid content makes
decolonization substantially more difficult. Hydrolytic/enzymatic
fat cleavage and respiration may be limited by low temperatures; however, this
may only be affected to a limited degree during transport. It is therefore important
to ensure storage stability by complying with the limit values for the water content
of the goods. Food components frequently
react with atmospheric oxygen in spoilage processes. Atmospheric oxygen may enter
into an addition reaction with unsaturated fatty acids through the simultaneous
assistance of light, heat and certain fat companion substances, and possibly also
traces of heavy metals. Rancidity caused by oxidative fat cleavage is particularly
noticeable in the case of shelled pistachio nuts, because the shelling process
results to a certain degree in exposure to atmospheric oxygen or to the steel
parts of the ship or the container walls, if not carefully covered. It is
therefore absolutely essential to store pistachio nuts in the dark and to protect
them from oxygen and metal parts, since otherwise they become brown-colored and
develop a rancid odor and taste.
| Active behavior | Pistachio nuts
have a very slight, pleasant odor. If they are transported or stored for an extended
period without ventilation, they spoil and release a strong odor. |
| Passive behavior | Pistachio
nuts are sensitive to unpleasant and/or pungent odors. |
| Active behavior | Risk of contamination
of other goods by fats and oils. | | Passive
behavior | Pistachio nuts are sensitive
to dust, dirt, fats and oils. | Pistachio nuts are impact-
and pressure-sensitive. They may suffer breakage. Excessive stack pressures must
in particular be avoided. If
ventilation has been inadequate (frost) or has failed owing to a defect, life-threatening
CO2 concentrations or O2 shortages may arise. Therefore, before anybody enters
the hold, it must be ventilated and a gas measurement carried out. The TLV for
CO2 concentration is 0.49 vol. %. Danger:
pistachio nuts may contain aflatoxin. The molds Aspergillums flatus and Aspergillums
parasitic us produce the toxin aflatoxin, which may be present in the cargo as
a result of an attack by the above-mentioned mold types. In general, this
is "country damage", i.e. The toxin is already
present in the pistachio nuts at the time of harvesting. As a rule, aflatoxin
is only found in individual pistachio nuts. If batches
intended as a human foodstuff are affected by this toxin, the product can no longer
be approved for human consumption. Pistachio nuts affected by aflatoxin cannot
readily be distinguished from the other nuts in a batch. The toxin may be detect.
Weight loss of up to 1% due to moisture
loss may occur. As pistachio nuts are a relatively
valuable cargo, there is considerable risk of theft. Insect infestation
is possible: mites, cockroaches, saw-toothed grain beetles, flour beetles, meal
moths, dried fruit moths and rats and mice may attack pistachio nuts. Pistachio
nuts from the previous year's harvest have a particular tendency to beetle infestation. The
quarantine regulations of the country of destination must be complied with and
a phytosanitary certificate and fumigation certificate may have to be enclosed
with the shipping documents. Information may be obtained
from the phytosanitary authorities of the countries concerned. |