Grain

Infobox on Grain
Example of Grain
Facts
Origin	-
Stowage factor (in m3/t)	-
Angle of repose	-
Humidity / moisture	-
Oil content	-
Ventilation	-
Risk factors	-

Grain

Description

Usually shipped in bulk, also in bags, especially seed grain. Grain is liable to damage by heating, infestation, sweat and contact with water. When grain gets wet, growth immediately starts, not only in the grain itself, but in the mould spores, yeast cells and bacteria, which are always present, causing respectively germination, fermentation and putrefaction.

Treatment for water damage is somewhat theoretical because of the necessity to apply treatment before deterioration sets in, and this is usually impossible, but when the condition of the grain is such that the cost of drying would be justified by the result, this is the only manner in which damage of this nature can be minimized.

If wetting is caused by salt water, drying out to recover the grain would not prove to be a financially viable exercise. Contamination by water causes deterioration and local heating, but general heating in grain is due to inherent vice as a result of the moisture content in the grain being too high or the period in the ship’s hold being excessive. Moisture levels for grain should be between 10% and 16%, but not exceeding 13% for maize.

Heating in dry materials may also be caused by the activity of bacteria. As a result of the feeding of bacteria, together with their breathing in of oxygen, carbon dioxide and water vapour pass out into the air. In the process heat is produced and the temperature of the commodity rises. The higher the temperature the more active are the bacteria in breaking down the food material into carbon dioxide and water vapour and thus more heat is produced. This may continue until the temperature reached is harmful to the bacteria and they move outwards from the ‘hot spot’ to found others around the first. Thus the heating and the damage become widespread in the commodity.

When heating within a bulk of a commodity takes place, due to bacteria activity, air convection currents carry water vapour upwards from the hot spot, this then condenses in the colder surface layer, raising its moisture content. This process may be carried far enough to cause the growth of moulds and bacteria and, in the case of grain, to cause sprouting. This type of water damage is essentially a surface phenomenon and is confined to the top few centimeters of a stack or bulk.

Delay in transit may of itself give rise to heating and so cause the grain to have the appearance of damage arising out of insufficient ventilation, but this condition may have arisen entirely as a result of delay. High temperatures in stowage can activate and cause infestation to develop. Grain in process of fermenting may give the appearance of having been in contact with oil, especially by reason of the odour.

Weevils impair the quality of grain, especially in the case of maize to be used for the manufacture of breakfast cereals.
Damaged grains should be disposed of as quickly as possible to avoid further deterioration. Apart from damage from an external cause, there is also the possibility of heat-damaged grain which occasionally occurs in grain stored against engine room bulkheads.

Green Corn
Subject to heating which may result in discoloration, toughening, drying out of the husk and shriveling of the corn. Attack by worm at the tip of the corn does not destroy the food value unless it is extended to the kernels themselves.

Reference is made to the relevant IMO publications of hazardous cargo.

Full information on this product is in the process of completion.