|Infobox on Groundnuts|
|Example of Groundnuts|
|Stowage factor (in m3/t)||-|
|Humidity / moisture||-|
Usually shipped in bags.
Old groundnuts have a dark appearance, dry and wrinkled, whereas fresh produce is well formed and of a light brown colour. Loss of weight from drying out can be considerable, especially in freshly harvested nuts. Heating due to inherent vice may be evident by its having commenced in the centre of the bags; groundnuts next to the sacking of the bags are usually found on examination to be sound or in better condition than those in the centre. Heating may also be caused by inadequate ventilation and crushing by pressure.
Some shippers export groundnuts during the new crop season mixed with the previous season’s nuts thereby increasing the danger of infestation. This practice, however, is much less common these days. All shipments should be accompanied by certificates as to their condition, quality and moisture content. Chinese groundnuts are usually shipped with a certificate to the effect that the moisture content is less than 9%, but damage is often found despite the statement showing a lesser moisture content.
Water action on groundnuts is serious because of the high protein content of the seed. Small amounts of water tend to make the seed rubbery and consequently difficult to process. If the damage is long-standing then the wetting of the nuts generally leads to fermentation.
The nuts, then, according to the amount of damage:
- give off an offensive smell
- appear slimy
- commence to heat
- ultimately mould
Hydrolysis in the oil and a marked increase in free fatty acid may follow. If the damage is excessive ultimately it becomes impossible to process the nuts by normal methods. Drying will improve matters but the oil is usually permanently damaged. The rise in acidity causes low yields on refining and, owing to the fact that the rise is usually accompanied by oxidation, poor quality refined oil is the result. These results depend on the amount of water and the length of time elapsing since the damage took place.
Full information on this product is in the process of completion.