Cocoa Beans
| Infobox on Cocoa Beans | |
|---|---|
| Example of Cocoa Beans |  |
| Facts | |
| Origin | This Table shows only a selection of the most important countries of origin and should not be thought of as exhaustive.
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| Stowage factor (in m3/t) |
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| Humidity / moisture |
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| Oil content | 39 - 60% |
| Ventilation | Recommended ventilation: air exchange rate 10 - 20 changes/hour (airing) Important: Good ventilation is required, so a suitable ventilation program must be drawn up depending upon external temperature, relative humidity, cargo temperature and moisture content of the cocoa beans. |
| Risk factors | Sweat/mold damage Under suitable ambient conditions (temperature > 25°C, high relative humidity, lack of oxygen supply) and due to their high oil content, cocoa beans have a tendency to self-heating and postfermentation. Some species of fungus, such as Aspergillus fumigatus, participate in the self-heating. |
Cocoa Beans
Description
Cocoa beans are the seeds, contained in a cucumber-like fruit, of the cacao tree, a member of the Sterculiaceae family. The flowers/fruit are borne directly on the trunk (cauliflory) and on thick branches (ramiflory). The yellowish, reddish to brownish fruits (botanically speaking, berries), which are of similar appearance to cucumbers, are divided into five longitudinal compartments, each containing up to 10 seeds (cocoa beans). As the fruits approach ripeness, the partitions break down and the seeds are located around the central funicle in a whitish pulp with a sweet/sour flavor.
The cocoa bean consists of the seed coat which encloses the cocoa kernel and almost solely consists of the two folded cotyledons, and the radicle. The cocoa kernel is the principal component for the production of cocoa products.
High-grade, criollo cocoa: the beans are large, roundish and brown in color. They have a delicately bitter, aromatic flavor and are easily processed.
Forastero or common grade cocoa: the beans are smaller than criollo cocoa beans, flattened on the side, have a dark reddish-brown to violet color and a sharper flavor. Forastero cocoa beans account for around 90% of the world's cocoa harvest.
The main zones of cultivation of the tropical cacao tree fall within a band 10° north and south of the equator. Central Africa produces approx. 75% of the world's forastero cocoa harvest, while criollo cocoa is primarily shipped from Central America (Venezuela, Ecuador) and from Sri Lanka and Indonesia.
Due to its high content of fat (cocoa butter), protein and carbohydrates, cocoa has a high nutritional value. Since cocoa contains only small amounts of substances such as theobromine (1 - 2%) and caffeine (0.2%), consuming it has no harmful side-effects.
In order to moderate the initially bitter flavor of cocoa and to develop the flavor typical of cocoa, the beans must be subjected to a fermentation process during which the highly bitter tannins present in the beans are oxidized, resulting in the formation of aromatic substances and the development of the typical brown to deep red-brown color of cocoa. As a result of the heat associated with fermentation, the cocoa beans lose their ability to germinate.
This process is performed after harvesting by heaping cocoa beans in layers in troughs, concrete pits or fermenting tanks. The quality of cocoa products (e.g. cocoa powder for beverages) is primarily determined by the quality of the raw cocoa. Fully ripened and correctly fermented cocoa beans are thus of a brown to dark red color and have a very fragile kernel with a pure, bitter flavor.
Apart from exhibiting the appearance and odor characteristic of their variety, perfect beans must be undamaged and ungerminated, must include no foreign matter or mold and must not be infested with insects or have suffered wetting damage. They must not smell sour, musty or smoky.
Poorly fermented cocoa beans are purple in color when underfermented or very dark in color when overfermented. They also have a slaty to solid kernel and an astringent (mouth-puckering) flavor. The core may have changed to a violet to yellowish white color. The excessive heating which occurs in overfermentation also results in butyric acid fermentation, which impairs quality.
The quality of cocoa beans is assessed according to the following criteria:
Good qualities:
- fully ripe, correctly fermented
- firm beans of uniform size with a dry weight of no less than 1 g
- loose and undamaged shell
- light to dark reddish-brown color
- readily crumbled, highly fragile kernel
Bad qualities:
- unripe and poorly fermented
- moldy cocoa beans
- strong violet color as a result of underfermentation; purple color when overfermented
- slaty and firm kernel as a result of underfermentation
- insect infested cocoa beans
- flat, unripe, small and broken cocoa beans
- germinated cocoa beans
- ham-like odor due to overfermentation
- smoky odor due to excessively long drying
The product should be shipped shortly after harvest, as extended storage (> 6 months) may result in losses due to the high relative humidities in the tropics.
Applications
For the production of cocoa powder and further processing into beverages, chocolates and desserts.
Shipment/storage
In bags of jute or sisal usually of a (gross) weight of 60 - 65 kg, rarely of up to 100 kg. New or high quality bags should be used due to the high value of the cargo.
Transport of bagged cargo in ventilated containers (coffee containers) is possible subject to compliance with lower limits for the water content of goods, packaging and flooring. The wooden flooring of the containers must be absolutely clean and dry. If it has been washed, it must have dried completely. Water content should be 12%, corresponding to a lumber equilibrium moisture content of 70%, so that the flooring does not constitute an additional source of water vapor to dampen the cocoa cargo and container atmosphere.
The cargo may be covered with paper which readily absorbs any moisture to provide protection from moisture damage.
Given the high value of a fully loaded cocoa container, a two-layer anticondensation film or nonwoven should be used to provide protection against dripping sweat.
Cocoa beans are also transported in standard containers using big bags or liner bags.
Alternatively, cocoa beans may also be transported on flatracks in ventilated holds. This approach is a cost-effective alternative to the costly ventilated containers, which are the ideal way to transport cocoa beans.
Shipped as break-bulk in bags and also in freight containers. Mostly shipped with a franchise to allow for normal shrinkage. Beans which have not been properly dried, and retain over 7,5% moisture, may turn mouldy in transit. If mould cannot be satisfactorily removed, the beans may have to be used for a less valuable product than that for which they were originally intended. Chocolate made from such affected beans will have a musty flavour. Damage to cocoa in the country of origin may not be noticeable from the external appearance of the bags, but should be established on sampling. Country damaged cocoa is usually of grey appearance and internally mouldy. This should not be confused with the natural bloom on the shell, which in appearance can suggest mould but is a natural occurrence and not detrimental to the commodity. On arrival at destination, bags should be stored in a dry place and in the event of water damage, cocoa should be reconditioned without delay. Cocoa has a natural inherent infestation, the tropical warehouse moth, which, if left untreated, can cause considerable damage to the bean plus a great degree of webbing. The condition is controllable by fumigation, and if so treated is normally acceptable to receivers. Cocoa beans are also liable to infestation by worm, which leads to a depreciation of value. Chocolate manufactured from such beans will itself be liable to damage from worm. Loss in colour of the shell through external sources usually has no detrimental effect. Some beans, if shipped in damp condition, may lose colour and become white. Cocoa beans in freight containers have shown damage by way of mould and/or discolouration of the beans. In many instances the condition of the bags giving no indication of the damage to the beans. The use of plastic material inside freight containers has led to considerable sweating and subsequent damage. Containers should be stripped immediately on arrival. Containers should offer good ventilation capability. Lining with wood will reduce condensation. In certain circumstances, where damage by sweat is encountered and the receivers are only prepared to accept the cocoa with considerable allowances, it may be possible to obtain a better result by separating the damaged beans to be sold separately, delivering the sound portion to the receivers.
Cocoa is packaged in Hussein/jute/poly lined bags or in bulk inside containers. In the latter mode a topless plastic inner liner is fitted into the container to hold the bulk. This is for sanitary reasons.
Condensation damage, taint and infestation are the main risks associated with carriage and loss of quality. When cocoa beans are overheated a separation process produces acid (emitting a sour smell) and combined with moisture this corrodes container paintwork. Direct contact of cocoa beans with steelwork should be avoided at all times.
Stowage (in containers)
When containers are shipped below deck, vigorous ventilation is necessary. A minimum air exchange rate of 20 changes/hour in the hold is recommended if continuous airing is to be achieved in the ventilated container. Ventilation of the hold must be arranged such that the air is blown in from beneath and rises upwards through the containers, so continuously removing warm, moist air. It is important to unpack the containers quickly on arrival at the port of destination, especially at cold times of year: when the containers emerge from the relatively well protected surroundings of the ship's hold and are exposed to the sometimes much colder outside air, the relative humidity in the containers may rise rapidly, resulting in the formation of condensation.
Using plastic materials to cover the container contents results in severe cargo sweating and consequent damage. Containers holding cocoa beans should, on principle, be stripped on arrival and have good ventilation (ventilated container). In order to ensure more effective airing of the cocoa bags stowed in the container, a particular stowage pattern, similar to that for coffee or pepper, should be used:
Two layers of bags are first laid crosswise in two stacks, with some space being left at the side walls (important, so that the ventilation openings in the floor are not blocked up). Free space, which should usually be of a size of 20 - 30 cm, is also left in the middle in order to provide a ventilation channel. A layer is then stowed lengthwise on the second layer. The next layer is again stowed crosswise, bridging the gap between the two stacks with one bag.
Stowing is continued in this manner until the container is full. Approx. 50 - 75 cm of free space must remain between the uppermost layer and the container roof in order to ensure free circulation of fresh air supplied from outside.
Free space (approx. 10 - 15 cm) must also remain between the container door and the stowed bags so that the necessary air circulation can be maintained here as well. The bags in the door area must be secured with lashings so that they do not slip into this free space in transit, which would block air circulation.
When the cargo is conventionally loaded on general cargo ships, the hatch covers should be slightly lifted or opened in dry weather (relative humidity < 80%) and in safe sea conditions in order to dissipate any water vapor and to permit temperature equalization between the outside air and cargo.
Container equipment which in general is used for the transport of cocoa beans includes:
| Size | Type | General information |
| 20/40 | GP | Particularly 20 ft's |
| 20 | High Vents | Bare steel to be sheathed |
| 20 | Open sides | Limited stocks |
It is essential that containers are properly prepared in order to achieve good quality transport out-turn as follows:
In GP containers:
- Floors and side walls to be covered with corrugated Kraft paper, cardboard, or a double layer of single paper;
- Special care required at container corners. Corrugation ribbing (rough side) must face the container walls, on floor and sides, except on top and facing the door where reverse applies;
- “Dry Bag” desiccants must always be used for condensation control, e.g. for a 20 ft GP undergoing maximum seasonal influences in north south traffic, 20 x 2 kg bags should be used. They are arranged in two rows of eight in a fore and aft direction on top of the Kraft paper covering the bags and four facing the doorway on the floor;
- Containers fitted with passive vents must have the vents taped off on the inside of the container to prevent moisture development
- See bag stow configuration diagrams under coffee
- Japanese receivers for shipments from Ghana insist on the container floor being overlaid with pallets in addition to aforesaid requirements.
In High Vents:
- There are two types of high vents namely: all steel inner or plywood sheathed;
- Floors to be covered with corrugated Kraft paper, cardboard, or a double layer of single paper;
- The bare steel version should be lined with corrugated Kraft paper, cardboard, or a double layer of single paper between the upper and lower vents on the side panels, front panel and on the doors;
- Both versions should have similar protection in way of the corner posts;
- After stuffing, depending on the routing, paper should be placed on the top of the cargo for sanitary reasons;
- Never use desiccants such as “Dry Bags” in high vents. (Only works in an enclosed space).
In Open sides: Short Intra Asia Runs:
- Care must be taken to ensure that side curtains are rolled down when on the terminal or on inland transport. Stowage on board ship must be under deck and with the curtains rolled up;
- No paper is to be placed on the floor as moisture is easily absorbed in this environment. Wooden gratings or pallets must be placed on the floor to avoid possible moisture damage to the bottom bags (only seasoned wood is to be used).
In Bulk:
- A polypropylene topless linerbag is used, large enough to fit into the sidewall corrugation ribs. For a standard 20 ft GP the bag should be of minimum dimensions: 550 cm (length) x 234 cm (width) x 240 cm (height);
- The topless linerbag is fitted to a span wire along the top rail of the container. (Avoid torsion in the bag so that tearing does not occur during loading). Double sided tape is used to lay the liner into the corrugation ribs of the container panels. This also prevents beans from slipping between the liner and container walls during loading;
- In order to contain the cocoa bulk, either an independent or integrated bulkhead must be fitted in way of the door in such a way that closing of the doors is possible on completion of blowing in the load (at least 10 cms clear of the door);
- Positioning of the bulkhead can be achieved by horizontal steel bars fitting into the doorway recess;
- A criss-cross lashing of 2 to 4 mm nylon rope, attached through the top rail lashing eyes, is used to secure a Kraft paper liner to the inner roof. (See fig);
- “Dry Bag” desiccants must always be used for condensation control. 16 x 2 kg bags are customary per 20 ft GP and arranged as per diagram (Bulk A) or as per fig;
- Affix a warning sticker to the door close to the seal similar to coffee diagrams;
- Manifests must clearly state that contents of the container is in bulk;
- Bulk loadings should only be accepted on FCL/FCL terms because of risks arising from incorrect rigging of inner liners by parties involved.
General handling instructions:
- In both terminal stacking and ship stowage due regard must be given to protection from radiant heat by allocating “cool stows”. Load lists and manifests must clearly record: AWAY HEAT/COOL STOW;
- Containers must be clean dry and odourless;
- When accepted on LCL terms never accept cocoa which is over 8% moisture content. In the event of this happening please refer to local trade management;
- Fumigation is normally to customers requirements in accordance with local regulations. (See fumigation);
- Cocoa beans are often transported under fumigation (phosphine) and appropriate warning stickers should be affixed to the container;
- Discharge ports must ensure that the right hand container door is cracked open on discharge for ventilation purposes (Ajar) and fixed by rope or chain to left hand door;
- Cargo to be received by consignee as soon as possible particularly in cold weather. (Under freezing conditions moisture arising from condensation is arrested).
Hooks must not be used in cargo handling as they subject the cargo to point loads, so damaging the bags. Due to their shape, plate or bag hooks apply an area load and are thus more suitable for handling bags. In damp weather (rain, snow), the cargo must be protected from moisture, since wetting and extremely high relative humidities may lead to mold growth.
Stowage space requirements (for containerised cargo)
Cool, dry, good ventilation.
The cargo should be stowed below deck away from sources of heat because there is a risk of self-heating and postfermentation. In this case, the container is no longer directly exposed to external weather conditions so that the temperature and humidity of the hold air become the decisive external influences. Temperatures below freezing point and major daily variations in temperature may result in spoilage of the cocoa beans. If the containers are nevertheless stowed on deck, they are best stowed as inner deck cargo. The risk of condensation is reduced by stowing between two other containers. However, stowage in this location should only be considered in the summer season if only small temperature gradients are anticipated during transport. Since frost must be expected at the port of destination during the winter months, stowage as inner deck cargo should be avoided.
Stowage, voyage and ventilation instructions (conventional shipments)
Stowage:
- The bags of cocoa beans should be loaded on top of double dunnage, crosswise applied. The dunnage should be applied in such a way that the bags cannot touch the steel tanktop plating. The bottom layer of dunnage should be applied longships, the top layer should be applied crosships. In this way possible sweat water on the tanktop can reach the bilges.
- In normal hatches, not double skinned and/or boxed shaped, the bags should be stowed free from the bare steel ship's parts. Preferably dunnage wood should be used.
- The bags must be stowed in such a way that the air flow from the ventilators is forced to go over and along the stow of cocoa beans. This means that the ventilation ducts should be stowed free in order to enable a free airflow and the top of the stow. Furthermore the bags in the hatchway, should be stowed free from the sides and ends of the hatchways in order to enable a free airflow.
- No fresh ballast water has to be taken in during the voyage and/or in the discharge port. This will definitely result in condensation on the steel plating which can effect the cocoa beans.
Ventilation
We herewith give the following advises regarding the transportation and ventilation of a cargo of cocoa beans, carried from a relative warm region to a cold(er) Northern region.
The temperature will slowly decrease during the sea voyage going to the North (and possibly increase again if approaching the discharge port in a climatologically milder region). The (nature and impact of the) general instructions given below are not to be considered exhaustive or conclusive and should at all material times be carefully considered as circumstances such as sea- and weather conditions may require and should by no means affect the duty of the carrier to take any and all precautions necessary to ensure a safe, complete and undamaged arrival and discharge of the cargo at the discharge port(s).
- The ventilation should be based on comparing the dewpoint of the hold air and the outside air. Ventilation should be carried out if the dewpoint of the hold air is higher than the dewpoint of the outside air. The hold dew point should be determined after stopping the ventilation for approx. 5 minutes.
- When cocoa beans are carried from warm regions to cold regions, the moisture in the cocoa beans will migrate out of the centre of the stow to the side of the stow and finally evaporate in the air.
This means that if ventilation is stopped because the dewpoint of the hold air is lower than the outside air, it should be checked again one hour after stopping the ventilation.
- The dewpoints should be determined every watch and at least four times per day.
- The holds should be entered and inspected daily on the presence of condensation against sides, bulkheads and underdeck areas.
In case of serious sweating, it may be considered to open the hatches partly during smooth weather and sea conditions only. It should be avoided at all times that spray and/or seawater enters the holds.
- In case of spray, ventilators on deck should be protected in order to avoid ingress of seawater and to safeguard the continuation of ventilation, when necessary.
- Ballasting with relative cold seawater should be avoided at all times.
- The bilges of the holds should be sounded daily and should be kept empty. An increase of the bilge level may indicate serious condensation.
- Ventilation should be continued in the discharging port(s), even during the discharge period, following the above instructions and weather and other port conditions permitting.
- All particulars should be noted in the (ventilation) logbook. At least the following particulars should be timely and properly recorded:
A. Outside air dry-bulb temperature
B. Outside air wet-bulb temperature
C. Outside air dew points
D. Hold air dry bulb temperature of all holds
E. Hold air wet-bulb temperature of all holds
F. Hold air dewpoint of all holds
G. Times of ventilation. Clearly mentioning stopping and starting times
H. Sea water temperatures
I. Weather/sea conditions
J. Particulars of the visual inspections in the holds
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. 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.
Attention must also be paid to stowage patterns which may be required as a result of special considerations, such as ventilation measures.
Temperature
| Designation | Temperature range |
| Travel temperature | 15°C |
| < 30°C | |
| 20°C |
Raw cocoa must not be stowed near heat sources. Rancidity and overfermentation readily occur at temperatures of > 25°C. Due to its high fat content, the cargo has a tendency to self-heating, and there may even be a risk of a cargo fire on contact with flammable substances, e.g. copra expeller. Cocoa beans absolutely must not be stowed in a container together with oily products.
External temperatures of > 30°C may readily occur during container packing. Severe cooling at night may result in container sweat if the temperature dips below the dew point.
In the hotter parts of the year, the temperature drop between the port of loading and unloading may be 15 - 20°C. In the cold parts of the year, however, the difference may be 30°C or more. Incoming cold polar air may cause sudden drops in temperature which, especially in container interiors, may result in a considerable increase in relative humidity. In this situation, the water content of the cargo is particularly important. Rapid and major cooling from the outside may readily increase relative humidity to 100%, resulting in condensation and wetting, vapor and mold damage to the cocoa beans. Cocoa beans must be protected from frost.
Humidity/Moisture
| Designation | Humidity/water content |
| Relative humidity | 70% - 75% |
| Water content | 6 - 8% |
| < 8% | |
| Critical water content | 8% |
| Maximum equilibrium moisture content | 65% |
It is recommended to demand on loading a certificate which states the intrinsic moisture content of the cocoa beans.
Cocoa beans are known to be highly hygroscopic (hygroscopicity) and to release large amounts of water vapor during transport. Water content has accordingly been observed to fall by 1 - 3% during extended voyages. Improperly fermented and dried cocoa beans have a greater tendency to release water vapor.
If the water content is < 6%, cocoa beans become brittle, while at a water content of > 8%, there is a risk of vapor and mold damage which cause depreciation which may go as far as total loss due to rot. An acceptable moisture content at time of receipt of the cargo should be no more than 7%, to provide a reasonable safety margin. Problems are most likely to occur at the start of the season, when moisture content is particularly high – frequently above 7,5%.
A fundamental distinction is drawn between two types of moisture damage: sweat damage and vapor damage.
Ventilation
Recommended ventilation: air exchange rate 10 - 20 changes/hour (airing).
Important: Good ventilation is required, so a suitable ventilation program must be drawn up depending upon external temperature, relative humidity, cargo temperature and moisture content of the cocoa beans.
Since the beans constantly release water vapor during the voyage, this vapor must be removed to the outside by suitable ventilation in order to reduce the risk of condensation in the event of unfavorable ambient conditions (e.g. sudden drops in temperature of the external air) and the risk of mold growth due to high relative humidity in the hold.
In the hold, it is particularly important for the covers which provide protection from dripping sweat (wooden dunnage, mats or jute coverings) to be arranged in such a way that air can still circulate freely. Ventilation channels and wells should be arranged in the stow.
Biotic activity
Cocoa beans display 3rd order biotic activity.
They belongs to the class of products in which respiration processes are suspended, but in which biochemical, microbial and other decomposition processes still proceed, which, as a result of possible postfermentation, are in particular associated with oxygen consumption and CO2 evolution. Although they lose their ability to germinate as a result of fermentation, poorly fermented cocoa beans may germinate.
Gases
Evolution of CO2 by postfermentation may endanger life. Thus, before anybody enters the hold, a gas measurement must be carried out. The threshold limit value (TLVD) is 0.49 vol.% CO2.
Risk factors
Self-heating / Spontaneous combustion
Oil content: 39 - 60%
Under suitable ambient conditions (temperature > 25°C, high relative humidity, lack of oxygen supply) and due to their high oil content, cocoa beans have a tendency to self-heating and postfermentation. Some species of fungus, such as Aspergillus fumigatus, participate in the self-heating.
One example is the spontaneous combustion of broken raw cocoa beans in a bulk load in the form of smoldering cavities or channels. There are four distinct phases in the development of the fire:
- 1st phase: General biological phase in which mesophilic microorganisms multiply in a wet spot, raising the temperature to approx. 37°C.
- 2nd phase: Phase involving the highest level of activity from thermophilic microorganisms at temperatures of up to approx. 70°C. Samples from the seat of the fire exhibit a particularly high content of thermophilic microorganisms.
- 3rd phase: The thermophilic decomposition phase which is characterized by exothermic chemical breakdown reactions, in particular by oxidation reactions between unsaturated fatty acids and atmospheric oxygen (the cocoa beans having a fat content of > 50%). A strong, pungent stench of fermentation becomes perceptible.
- 4th phase: The pyrophoric gas phase, in which pyrophoric carbon and gases (e.g. phosphine) are formed. The resultant abrupt increase in temperature gives rise to smoldering cavities and channels within the bulk load.
Sweat damage (mold damage):
Recognizable by spots on the bag fabric caused by drops of dirty water. Under these spots, there are clusters of cocoa beans covered with white mold and stuck together. In serious cases, the mold penetrates into the kernel of individual beans. As a result, these then smell and taste musty. Such losses are usually limited to only a few bags in a consignment and are caused by the formation of ship sweat below deck, especially at night when the surrounding atmosphere and thus the outer walls of the hold cool down. If the upper layer of bags in the hold is inadequately covered, the dripping cargo sweat cannot be absorbed, penetrates into the bags containing the cocoa beans and causes the damage described above.
Vapor damage:
This is caused by excessive relative humidity in the hold or container. While the cocoa beans have only a thin covering of mold, from time to time the damage affects the entire contents of the bags stowed in a hold. Vapor damage is thus generally much more extensive than sweat damage. Marked mold growth is not normally observable, but aroma and flavor are still considerably degraded. For this reason, care must be taken not only to prevent formation of sweat, but also to ensure favorable relative humidity values in the hold/container.
On arrival in the port of discharge, the water content of the cargo should be just above 6%; a higher intrinsic moisture content would expose the cocoa to excessive risk on subsequent storage. The product should also be shipped shortly after harvest as the consequent extended storage in the tropical countries of origin may readily result in losses due to the prevailing high relative humidities.
Since cocoa beans are strongly hygroscopic, they must not be stowed together with moisture-releasing goods, such as copra, bran or rafted logs. Loss of moisture from the cargo and the consequent release of water vapor from the cocoa beans into the surroundings result in the formation of condensation on surfaces in the hold or on the cargo which may cause considerable damage.
Apart from containing water, the cocoa beans also contain enzymes which bring about postfermentation in the hold. Incorrect covering of batches of cargo resulting in obstruction of air circulation may in particular cause damage.
Bags damaged by rain, seawater and condensation must be rejected during acceptance of a consignment and, whether moist or redried, must never be stowed together with intact bags as the salt has the effect of greatly promoting the hygroscopicity of the raw cocoa, which may demonstrably lead to severe losses. In cases of doubt, already dried bags must be subjected to a seawater test (silver nitrate method). When accepting a cargo from lighters, difficulties obviously arise when rejecting seawater-damaged bags. The water content of the jute bags should be at most 9% (which is already the critical value). Measurements on jute sacks in containers have on occasion revealed values of up to 30%.
When transporting cocoa beans in containers, care should be taken to ensure that the water content of the cocoa beans on packing is approx. 6 - 8%, which corresponds to an equilibrium moisture content of 75 - 85% (at 20°C) and a temperature/dew point difference of 5 - 3°C. These are values which entail greater problems from the outset than are encountered, for example, with coffee shipments, because even the lower water content limit of 6% corresponds to the mold growth threshold of 75%. Moreover, cocoa beans have an elevated fat content which, in conjunction with moisture, results in hydrolytic/enzymatic fat cleavage and self-heating of the cocoa beans. The slight temperature/dew point difference also shows how rapidly the dew point of the cocoa cargo is reached on cooling. It is thus recommended to insist on a water content of 6% when transporting cocoa beans in containers.
Odor
Active behavior: Cocoa beans have a characteristic, strong odor. This odor may taint, for example, raw coffee, which should thus not be stowed together with cocoa beans in a hold/container. Excessively long fermentation may impart a typical, ham-like odor to the beans; a smoky odor is due to incorrect drying.
Passive behavior: Cocoa beans are very odor-sensitive (particularly towards copra bran, pepper and palm kernels). Due to the elevated odor-sensitivity, holds or containers must not smell of previous loads (e.g. citrus odor, odor of leather, pepper, chemicals etc.). Before containers are loaded, they must be inspected to establish whether they are free of foreign odors.
Contamination
Active behavior: Cocoa beans do not cause contamination.
Passive behavior: Cocoa beans are sensitive to contamination by dust, dirt, fats and oils. Raw cocoa is particularly sensitive to cement and coal dust: cement dust passes through the bags onto the beans, causing major losses.
Mechanical influences
Point loads applied for example by hooks may result in damage (tears) to the bags and thus to losses of volume. Plate or bag hooks, which, due to their shape, distribute the load and reduce the risk of damage, should thus be used. Exposure to moisture in particular increases the susceptibility of jute bags to rotting, which reduces their mechanical strength.
Toxicity / Hazards to health
Evolution of CO2 due to respiration and postfermentation. Take care when entering the hold. Possible oxygen shortage! Use gas detector.
Shrinkage/Shortage
Shrinkage of 1% (normal), rising in exceptional cases to 3%, should be anticipated due to drying during the voyage. "Slack bags" should be rejected on acceptance of a consignment as the slackness indicates short quantities.
Insect infestation / Diseases
Before the means of transport is loaded, the cargo should be fumigated (obtain a fumigation certificate).
Typical pests are the cocoa and meal moth, together with ants and cockroaches, which may cause severe losses by eating and contaminating the cargo. Infested cargo is usually fumigated to eliminate the living insects. On board pest control using fumigation tablets may result in dust deposits on the bags. This dust still contains residues of the poison, which can also be highly hazardous to humans.
Insect infestation usually originates in the country of production when the raw cocoa has been stored for an extended period; but insect infestation may also occur on long voyages.
Mold infestation: mold growth may considerably reduce the quality of cocoa beans. Scientific investigations have revealed eight mold species which produce foul-smelling substances and also cause the tissue of the beans to decompose. Some species participate in self-heating of the cargo, while others may form strong toxins.
If the molds find favorable living conditions, i.e. when the critical water content of 8.5% is exceeded at an equilibrium moisture content of approx. 88%, the molds rapidly develop within 3 - 4 days, at the end of which period thousands of spores have formed on the surface of the cocoa beans.
The number of mold spores may also be used to assess the quality of the cargo:
| Category | Number of spores/gram | Macroscopic examination of samples | Suitability for use | Quality |
| 1 | 100 - 1.000 | No traces of mold growth | Yes | High |
| 2 | 1000 - 10,000 | Slight development of molds on individual beans | Yes | Low |
| 3 | 25,000 - 100,000 | Slight to considerable mold growth on all beans | Uncertain | Low |
| 4 | > 100,000 | Severe mold growth over entire sample | Zero | Poor |
Note:(Source including Transport Information Service of the GDV)