Almonds [German version]

Table of contents

Product information
  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 Mandeln
English Almonds, almond kernels
French Amandes
Spanish Almendras
Scientific Prunus dulcis, Amygdalis communis
CN/HS number * 0802 10 ff.

(* EU Combined Nomenclature/Harmonized System)

Product description

Almonds are the single-seeded, plum-sized stone fruits of the almond tree (Rosaceae family). Almonds are native to the Middle East and Central Asia. The stone fruit encloses a kernel, the actual almond, which is approx. 2 cm long and covered in a light brown seed coat. The seed coat contains antioxidants which protect the oil-rich almonds from penetration by atmospheric oxygen so preventing them from becoming rancid (oxidative rancidity).

Almonds 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.

Sweet almonds (Prunus amygdalus dulcis): these also include the soft-shelled almond (Prunus amygdalus fragilis), which has a porous, highly fragile shell. Sweet almonds are generally of an oval, flattened or roundish shape, are tender and have a sweetish flavor.
Bitter almonds (Prunus amygdalus amara): These are generally smaller and more pointed than sweet almonds and have an astringent, bitter flavor. Bitter almonds contain approx. 2 – 4% of the glycoside amygdalin, which, in the presence of water and the enzyme emulsin (e.g. in the human digestive tract), releases hydrocyanic (prussic) acid, which is harmful to human health: as few as 7 – 10 bitter almonds eaten raw can cause severe problems and may even be fatal to children. Boiling or baking of the bitter almonds drives off most of the hydrocyanic acid so that there is no need to fear any harmful effects from eating them once cooked.
Mountain almonds: roundish, flatter and smaller than the other two types, unnotched, bitter flavor.

Almonds are harvested once their hull has opened and the green hull is immediately removed in order to prevent mold growth and the nuts are then dried in the sun or in dryers.

Oil content:

53 – 59% [1]
54% [2] soft-shelled almonds
40 – 55% [3]

Quality / Duration of storage

Almonds are valued on the basis of their shell content; a thicker shell means a smaller proportion of the edible kernel. A distinction is drawn between hard, medium hard, soft and paper-shelled almonds, this last type also being known as soft-shelled almonds.

Almonds must be sound, dry, with large white kernels which are high in fat and have smooth skins; they must have the correct aroma and a pronounced almond flavor.

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

Maximum duration of storage and transport is as follows:

Temperature Relative humidity Maximum duration of storage Source
-3 – 0°C 65 – 70% 12 months [5]

Intended use

Sweet almonds are mainly eaten raw and are also used to produce bakery products, confectionery, marzipan and dessert powder and for roasting.

Bitter almonds are mainly used to produce bitter almond oil.


(Click on the individual Figures to enlarge them.)

Photo, almonds

Figure 1
Photo, almonds

Figure 2
Drawing, almonds

Figure 3
Photo, almonds

Figure 4
Photo, almonds

Figure 5
Photo, almonds

Figure 6
Photo, almonds

Figure 7
Photo, almonds

Figure 8

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, Spain, Portugal, Italy, Cyprus, Greece, Bulgaria
Africa Morocco
Asia China, Israel, Iran
America USA (California), Argentina
Australia Australia

The largest almond crops are grown in the Mediterranean countries and in California (no late frosts, mild climate, winter rain).

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Almonds are packaged in, among other things, polysacks (5 kg), boxes (10 – 25 kg), cartons (10 – 20 kg) drums (50 and 100 kg) and flat jute fabric bags (50 kg).

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Symbol, general cargo

General cargo


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

2.20 m³/t (flat jute fabric bags, 50 kg) [1]
1.95 – 2.09 m³/t (boxes) [11]
2.03 – 2.09 m³/t (bags) [11]
3.34 m³/t (large drums) [11]
2.50 – 2.65 m³/t (bags from India) [11]
1.97 m³/t (boxes or cartons) [14]
1.70 – 2.55 m³/t (shelled in bags) [14]
2.55 – 3.12 m³/t (unshelled in bags) [14]

According to [11], 20% additional stowage space must be allowed for unshelled almonds in bags.

Stowage space requirements

Cool, dry, good ventilation. The cargo should be covered with wooden dunnage, mats or jute coverings because contact with metal parts of the ship’s hull or container entails a risk of rancidity.


Fiber rope, thin fiber nets for bags; marker pen, oil crayon for cartons

Cargo securing

In order to ensure safe transport, the bags 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

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

For this reason, precise details should be obtained from the shipper as to the travel temperature to be maintained.

Designation Temperature range Source
Favorable travel temperature range 0°C [1]
-3 – 0°C [5]

The stated travel temperatures are the ideal temperatures for achieving the longest possible storage life, but travel temperatures of approx. 5 – 25°C are also feasible (depending on journey length), so it is not absolutely necessary for the product to be transported as chilled goods.

Temperatures > 30°C should not prevail for a long period, as such temperatures promote respiration of the cargo and cause self-heating.

Almonds should not be stowed near heat sources (engine room bulkhead, heated tanks).

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RF Humidity/Moisture

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

Precise details should be obtained from the consignor as to the relative humidity to be maintained during the voyage.

Designation Humidity/water content Source
Relative humidity 65 – 75% (almonds) [1]
65% (almond kernels) [1]
65 – 70% [5]
Water content 4.5 – 8% (almonds) [1]
3.5 – 7% (almond kernels) [1]
6% (soft-shelled almonds) [2]
Maximum equilibrium moisture content 65% [1]

Almonds 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.

Sprinkling with water to increase the weight on loading (or „baptism“) may also cause moisture damage. Avoid wettening liquids.

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.

Moisture damage is more frequent with shelled almonds. Onset of mold growth occurs at relative humidities of as low as > 65%. Slight moisture damage may be rectified by ventilation.

Dry almond kernels should have a water content of < 7% as there is otherwise a risk of mold growth.

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RF Ventilation

Almonds 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

Almonds 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

Almonds (especially when moist) produce ripening gases (particularly CO2) as a result of the respiration processes which continue postharvest. 

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:

53 – 59% [1]
54% [2] soft-shelled almonds
40 – 55% [3]

Because of their tendency to self-heating, almonds may behave like substances from Class 4.2 of the IMDG Code. See also IMO Code of Safe Practice for Solid Bulk Cargoes.

Excessive stack pressure results in self-heating. Oils which have accumulated in the jute packaging fabric encourage this behavior.

As a basic principle, a high oil content (especially in almond kernels) encourages the tendency to self-heating.

Fat decomposition in almonds 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 almonds 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 almonds to form carbon dioxide and water, a process which is associated with considerable evolution of heat.

Self-heating of almonds 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 almonds 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 almonds with a high water content tend in particular towards rapid self-heating and may also ignite. Self-heating of almonds 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 almonds, 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 almonds 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 Almonds have a very slight, pleasant odor.
Passive behavior Almonds are highly odor-sensitive. Shelled almonds (almond kernels) in particular accept any odor and, if so affected, become worthless.

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RF Contamination

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

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RF Mechanical influences

Almonds are impact- and pressure-sensitive. Particularly high stack pressure must be avoided because there is a risk of self-heating due to the oils which accumulate in the jute fabric.

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RF Toxicity / Hazards to health

Evolution of CO2 due to respiration, especially with moistened goods. Take care when entering the hold. Use gas detector.

Bitter almonds contain approx. 2 – 4% of the glycoside amygdalin, which, in the presence of water and the enzyme emulsin (e.g. in the human digestive tract), releases hydrocyanic (prussic) acid, which is harmful to human health: as few as 7 – 10 bitter almonds eaten raw can cause severe problems and may even be fatal to children.

Boiling or baking of the bitter almonds drives off most of the hydrocyanic acid so that there is no need to fear any harmful effects from eating them once cooked.

Danger: almonds 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 almond at the time of harvesting. As a rule, aflatoxin is only found in individual almonds. If batches intended as a human foodstuff are affected by this toxin, the product can no longer be approved for human consumption. Almonds 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 is tolerated.

Loss of volume may be caused by tears in bags during conventional loading or by theft.

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RF Insect infestation / Diseases

Mites, cockroaches, sawtoothed grain beetles, flour beetles, meal moths, dried fruit moths and rats and mice may attack almonds. Almonds from the previous year’s harvest have a particular tendency to beetle infestation.

On acceptance, the cargo must be inspected for insect infestation. Have an inspection certificate issued by a surveyor.

Insect infestation usually has its origin in the country of production. The time of infestation may be determined with some certainty by the stage of development of the pests, especially moths (frequent infestation by the almond moth).

The development of maggots is promoted on even slight exposure to heat.

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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