Prunes [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 Pflaumen, getrocknet (Backpflaumen)
English Prunes (dried plums)
French Pruneaux
Spanish Ciruelas pasas
Scientific Prunus domestica
CN/HS number * 0813 20 00


(* EU Combined Nomenclature/Harmonized System)



Product description

Prunes are the fully ripe fruit still containing their stone of the plum tree (rose family, Rosaceae) which have been preserved by drying (air, sun or artificial drying) (dried fruit). The plum tree is native to Asia Minor and is now found throughout Europe and all over the world.

The following types are distinguished:

Prunes: fresh, blue-black, glossy; form a whitish coating of crystallized sugar after extended storage.
Dipped prunes: prunes which have formed a coating of crystallized sugar but regain a blue-black, glossy appearance by dipping in boiling water.
Steamed prunes: prunes which have been given a glossy appearance by steam treatment.
Slabs: waste product intended for industrial use.


Quality / Duration of storage

The quality of prunes is determined by size, aroma, fleshiness and tenderness of the skin.

Fresh prunes have a blue-black, glossy appearance, are highly aromatic, with soft flesh and skin and have a sourish flavor and small stones.

Prunes which have dried out have a matt, whitish appearance due to a covering of sugar crystals.

Prunes have a storage life of several years at storage temperatures of -1 - +4°C.


Intended use

Prunes are mainly eaten raw and used as an ingredient in mixed fruit, trail mixes and muesli.


Figures

(Click on the individual Figures to enlarge them.)

Photo, prunes

Figure 1
Photo, prunes

Figure 2
Photo, prunes

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 France, Italy, Balkan States
Africa  
Asia  
America Argentina, Chile, USA (especially California, Oregon)
Australia Australia


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Packaging

Prunes are packaged in, among other things, 12.5 kg paperboard cartons, plywood jointed boxes or also in flat linen fabric bags (industrial grade product).

When packaged in corrugated or millboard cartons, the product should be transported on pallets. The packaging size should be so selected that the dimensions of the individual area modules or area module multiples are conformed to the conventional pallet sizes (800x1200 mm and 1000x1200 mm) and cargo units may thus be produced.


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Transport

Symbols

Symbol, general cargo

General cargo


Temperature-controlled



Means of transport

Ship, railroad, truck


Container transport

Standard containers / refrigerated containers are used, subject to compliance with lower limits for water content of goods, packaging and container flooring.


Cargo handling

Since the packages are sensitive to impact, appropriate care must be taken during cargo handling.

In damp weather (rain, snow), the cargo must be protected from moisture, since this may lead to mold, rot, fermentation and tackiness.


Stowage factor

3.10 m³/t (flat linen fabric bags, 50 kg) [1]
1.20 m³/t (26 kg cartons) [1]
1.60 m³/t (boxes, 25 kg) [1]
1.69 m³/t (jointed boxes, 10.8 kg) [1]


Stowage space requirements

Cool, dry, good ventilation if required


Segregation

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


Cargo securing

In order to ensure safe transport, the cargo must be stowed and secured in the means of transport in such a manner that it cannot slip or shift during transport. If loss of volume and degradation of quality are to be avoided, the packages must not be damaged by other articles or items of cargo.


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Risk factors and loss prevention

RF Temperature

Prunes require particular temperature, humidity/moisture and possibly ventilation conditions (SC VI) (storage climate conditions).

Precise details should be obtained from the consignor as to the storage temperature to be maintained.

Designation Temperature range Source
Favorable travel temperature 4 - 20°C [1]
10 - 15°C [4]
-1 - +4°C [5]


Excessively low travel temperatures cause candying due to deposition of glucose (crystallization).

At temperatures < 10°C, possible mite growth is inhibited.

Chemical reactions proceed rapidly at temperatures > 25°C and this may result in syrup formation. There is a risk of the syrup seeping out of the packaging and damaging other goods. On the other hand, they dry out, discolor and harden and, in this state, are readily infested by maggots.

The product should not be stored close to heat sources so that drying out, hardening and candying cannot occur. Temperature variations have a negative impact.


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RF Humidity/Moisture

Prunes require particular temperature, humidity/moisture and possibly ventilation conditions (SC VI) (storage climate conditions).

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

Designation Humidity/water content Source
Relative humidity 60 - 70% [1]
Water content 18 - <20% [1]
24%, max. 35% [5]
Maximum equilibrium moisture content 65% [1]


The steep gradient of the sorption isotherm for prunes indicates the strong hygroscopicity of these dried fruits. At a water content of 20%, prunes are at equilibrium with 60% relative humidity. At an equilibrium moisture content of 70%, the water content rises to 30%.

Sorption isotherm, prunes

Figure 4



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RF Ventilation

Prunes require particular temperature, humidity/moisture and possibly ventilation conditions (SC VI) (storage climate conditions).

If the product is at "shipping dryness", i.e. if there is no risk of degradation by mold etc. due to water content, ventilation is not required. If this is not the case, the following ventilation measures should be implemented:

Recommended ventilation conditions: air exchange rate: 6 changes/hour (airing)

Unsuitable stowage spaces and inadequate ventilation promote heat build-up and thus syrup formation.


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RF Biotic activity

Prunes display 3rd order biotic activity .

They belong to the class of goods in which respiration processes are suspended, but in which biochemical, microbial and other decomposition processes still proceed.


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RF Gases

No risk.


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RF Self-heating / Spontaneous combustion

Chemical reactions proceed rapidly at temperatures > 25°C. Considerable syrup formation and self-heating may be the result.


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RF Odor

Active behavior Prunes have a slight, pleasant odor.
Passive behavior Prunes are highly odor-sensitive and should not be stowed in the vicinity of onions and other alliaceous vegetables as their essential oils cause odor-tainting.



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RF Contamination

Active behavior At temperatures > 25°C and under excessive stack pressure, syrup forms. There is a risk of the syrup seeping out of the packaging and damaging other goods.
Passive behavior Prunes are extremely sensitive to contamination.



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RF Mechanical influences

The packages must be secured appropriately in the hold or container so that they cannot move during transport. In the case of container transport, it is also important for the goods to be secured in the door area so that they cannot fall out of the container when the doors are opened.


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RF Toxicity / Hazards to health

Prunes infested by mites may cause severe gastrointestinal conditions if eaten.


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RF Shrinkage/Shortage

The normal weight loss due to a reduction in the moisture content of the product is approx. 1%.


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RF Insect infestation / Diseases

Exposure to heat and moisture may result in mite infestation, which may make the prunes inedible and cause severe gastrointestinal conditions. Mite infestation may be determined by examination with a magnifying glass: mites may be distinguished from crystallized glucose because they are whitish, slow moving dots. Development from the egg to imago (sexually mature insect) takes approx. 10 days.

Under appropriate temperature and humidity conditions, there is also a risk of infestation by cockroaches, moths (dried fruit moth, meal moth, tobacco moth), beetles (sap beetles, sawtoothed grain beetles and flour beetles), rats, mice and ants.

If infested by insects (mites, maggots etc.), prunes must be reconditioned by fumigation.


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