c.) Storage

Before the cocoa beans are stored they should be sorted to remove any defective beans including those that are flat, shrivelled, black, mouldy, germinated, insect damaged, small and/or fused together. The cocoa beans should then be properly identified by lots, either at the farm level or in out-of-farm warehouses. Any bags used to store the cocoa should be labelled to indicate that they are suitable for food contact use, new, unused, clean and sufficiently strong and properly sewn or sealed to withstand transport and storage and discourage pest infestation. Moreover, in regions where cocoa production overlaps with allergenic crops (e.g. peanuts or sesame), new or cocoa dedicated bags must be used to avoid cross-contamination. Maintaining the correct storage conditions for cocoa beans in the tropics can be challenging, mainly because of high temperature and relative humidity, and therefore storage periods should not exceed three months unless special precautions are taken. The hazards to quality arising from storage in the tropics are re-humidification and subsequent secondary mould development, both internally and on the shell, fat degradation, infestation and possible contamination from other stored products.
 

i.) Mould development

Dried cocoa beans can absorb moisture if the humidity is high. At 8% moisture content, cocoa beans are in equilibrium with the ambient relative humidity (about 70%) and normal temperatures in the tropics. Where the relative humidity exceeds this level for prolonged periods there is danger of re-humidification with secondary external and internal mould development.
 

ii.) Fat degradation

Prolonged storage under humid conditions can also lead to a rise in FFA concentration. The normal FFA in the cocoa butter from beans which have been prepared correctly and exported without undue delay will be less than 1%. This compares with an EU limit for FFA in cocoa butter of 1.75%.
 

iii.) Infestation

Wherever cocoa is stored in the tropics it is liable to become infested with various types of moths, beetles and mites. Some of these pests have a life cycle of only a few weeks in the tropics and can rapidly increase in numbers. Pest monitoring and reporting by the workforce and the timely use of approved insecticides is an important part of an in- store integrated crop and pest management strategy. Cleanliness and good stock control are essential, but in some cases this will need to be supplemented by the careful use of approved insecticides and in the last resort by approved methods of fumigation. In the latter case, appropriate documentation accompanying the cargo should state in clear and correct terms the fumigants and the quantities that were used.

The construction and operation of a cocoa store helps to minimise the hazards that have been described. Such stores should be well- maintained to ensure they are kept clean, properly ventilated and weatherproof. They should have a concrete floor and walls of brick or concrete blocks. A wooden floor or walls should not be used because the spaces between the joints offer places where pests can breed. The doors and windows should provide adequate light and ventilation but exclude pests (birds, rodents, etc.). However, the cocoa should not be stored in direct sunlight nor near heating sources to avoid the possibility of temperature differentials, condensation and water migration.

Sacks should be stored on pallets off the floor. Wooden pallets should have a layer of protective polythene or plastic between the surfaces of the pallet and the first layer of sacks if the pallets have been treated with wood preservative containing phenols. Extra care is required if such sheeting is used as condensation may occur on the plastic thereby damaging the cocoa. The stacks should not exceed 30 tons and should be separated from the walls to allow free access for inspection and sampling.

The use of battery powered or liquified petroleum gas (LPG) fueled forklift trucks rather than diesel oil in stores will reduce the risk of contamination from spillages of fuel and from fumes.

If and when fumigation is performed it should be carried out under expert supervision according to national requirements using well maintained gas proof sheeting of appropriately low permeability. Sufficient fumigant must be added and maintained for a sufficiently long period of exposure (at least 5 days for phosphine) commensurate to eradicate the particular pest species targeted. This is not only to ensure that the infestation is eradicated completely but also to minimise the amount of fumigant used and reduce the risk that the insect species develops resistance to the fumigant.