Pistachio nuts [German version]

Table of contents

General:
Product information
Packaging
Transport
  Container transport
  Cargo securing


Risk factors and loss prevention:
Temperature Odor
Humidity/Moisture Contamination
Ventilation Mechanical influences
Biotic activity Toxicity / Hazards to health
Gases Shrinkage/Shortage
Self-heating / Spontaneous combustion Insect infestation / Diseases




Product information

Product name

German Pistazien
English Pistachio nuts
French Pistaches
Spanish Pistachos
Scientific Pistacia vera
CN/HS number * 0802 50 00


(* EU Combined Nomenclature/Harmonized System)



Product description

Pistachio nuts are the single-seeded stone fruit of the pistachio tree (sumach family, Anacardiaceae), which is native to the Mediterranean area.

Pistachio nuts are shell fruit (nut types). Because of their similar characteristics with regard to transport, particularly their high oil content, their requirements regarding care during storage and transport are the same as those of oil-bearing seeds/fruits.

The pistachio has pinnate leaves and bears stone fruit 1 - 2 cm in size, whose light brown shell opens when ripe (see Figure 1). The kernels have a brown seed coat. The seed coat contains antioxidants which protect the oil-rich seed from atmospheric oxygen so preventing it from becoming rancid (oxidative rancidity). After removal of the brown seed coat, the brilliant green color of the kernels is a sign of freshly harvested nuts (see Figures 2 and 3).

There are many cultivars of pistachio nuts, which are also known as green almonds.

Oil content:

45 - 54% [1]
55% [2]



Quality / Duration of storage

Acceptable pistachio nuts must be of sound average quality, dry, predominantly greenish (old nuts are often of a yellowish color), contain no dust or foreign admixtures and have their characteristic odor and flavor. 95 - 98% of nuts in their shell must be open.

It is very important for the surveyor to ascertain the year of harvest: it must be taken into consideration that the pistachio nuts may be mixed with nuts from the previous year's harvest. This possibility must not be disregarded when determining whether or not loss has occurred in transit. Pistachio nuts from the previous year's harvest have a tendency to beetle infestation and rancidity.

Roasted and salted nuts may be stored under cool, well ventilated and dry conditions for up to three weeks and for a little longer in winter. If the maximum duration of storage is exceeded, quality may be impaired, e.g. loss of the brilliant green color and rancidity.


Intended use

Kernels, preferably from Italy, Turkey and Greece, are used as a seasoning (for meat and sausage products) or as a flavoring in chocolate confectionery, bakery products and ice cream.

Pistachio nuts are sold roasted and salted in their shells for consumption as a snack food and are also used as a raw material for pistachio nut oil.


Figures

(Click on the individual Figures to enlarge them.)

Drawing, pistachio nuts

Figure 1
Photo, pistachio nuts

Figure 2
Photo, pistachio nuts

Figure 3



Countries of origin

This Table shows only a selection of the most important countries of origin and should not be thought of as exhaustive.

Europe Turkey, Greece, Italy, South of France
Africa Tunisia
Asia Iran, Afghanistan, India, Syria, Iraq
America USA (California), Mexico
Australia  


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Packaging

Pistachio nuts are packaged in, among other things, wooden boxes (pistachio kernels), cartons, polysacks (25 - 60 kg) and in jute bags (60 kg).

Airtight packaging is ideal because pistachio kernels readily absorb moisture from the air, so becoming limp and because oxygen promotes rancidity.


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Transport

Symbols

Symbol, general cargo

General cargo


Temperature-controlled



Means of transport

Ship, truck, railroad, 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

1.95 - 2.12 m3/t (cartons) [11]
1.67 - 1.81 m3/t (kegs) [11]


Stowage space requirements

Cool, dry, good ventilation


Segregation

Marker pen, oil crayon (for cartons)


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.



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Risk factors and loss prevention

RF Temperature

Pistachio nuts 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 Source
Favorable travel temperature range 5 - 25°C [1]
0°C [5]


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 this results in impaired flavor.


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RF Humidity/Moisture

Pistachio nuts require particular temperature, humidity/moisture and ventilation conditions (SC VII) (storage climate 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.


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RF Ventilation

Pistachio nuts require particular temperature, humidity/moisture and ventilation conditions (SC VII) (storage climate conditions).

Recommended ventilation conditions: air exchange rate: at least 10 changes/hour (airing)


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RF Biotic activity

Pistachio nuts display 2nd order biotic activity.

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.


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RF Gases

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.%.


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RF Self-heating / Spontaneous combustion

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, a 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


Hydrolytic/enzymatic 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 a 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 bleachability of the oils are also negatively affected. The oil obtained complicates refining of the crude oils in subsequent processing, because a higher free fatty acid content makes decolorization 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.


Oxidative fat cleavage:

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.


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RF Odor

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.



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RF Contamination

Active behavior Risk of contamination of other goods by fats and oils.
Passive behavior Pistachio nuts are sensitive to dust, dirt, fats and oils.



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RF Mechanical influences

Pistachio nuts are impact- and pressure-sensitive. They may suffer breakage. Excessive stack pressures must in particular be avoided.


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RF Toxicity / Hazards to health

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 Aspergillus flavus and Aspergillus parasiticus 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 detected using UV light.


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RF Shrinkage/Shortage

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.


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RF Insect infestation / Diseases

Insect infestation is possible: mites, cockroaches, sawtoothed 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.


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