Linseed
| Infobox on Linseed | |
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| Example of Linseed |  |
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| Origin | - |
| Stowage factor (in m3/t) |
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| Humidity / moisture |
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| Ventilation | See text |
| Risk factors | See text |
Linseed
Description / Application
Flax (also known as common flax or linseed) is a member of the genus Linum in the family Linaceae. It is a food and fibre crop that is grown in cooler regions of the world. Flax fibres are taken from the stem of the plant and are two to three times as strong as those of cotton. As well, flax fibers are naturally smooth and straight. Europe and North America depended on flax for cloth until the nineteenth century, when cotton overtook flax as the most common plant used for making linen paper. Flax is grown on the Canadian Prairies for linseed oil, which is used as a drying oil in paints and varnish and in products such as linoleum and printing inks. It is native to the region extending from the eastern Mediterranean to India and was probably first domesticated in the Fertile Crescent. Flax was extensively cultivated in ancient Ethiopia and ancient Egypt.
Flax is grown for its use as an edible oil, as a nutritional supplement, and as an ingredient in many wood finishing products. Flax is also grown as an ornamental plant in gardens. Flax fibers are used to make linen. The Latin species name usitatissimum means most useful, pointing to the several traditional uses of the plant and their importance for human life.
Flax seeds come in two basic varieties: (1) brown; and (2) yellow or golden. Most types have similar nutritional characteristics and equal numbers of short-chain omega-3 Fatty Acids. The exception is a type of yellow flax called solin (trade name Linola), which has a (completely) different oil profile and is very low in omega-3 FAs. Although brown flax can be consumed as readily as yellow, and has been for thousands of years, it is better known as an ingredient in paints, fiber and cattle feed. Flax seeds produce a vegetable oil known as flaxseed or linseed oil, which is one of the oldest commercial oils, and solvent-processed flax seed oil has been used for centuries as a drying oil in painting and varnishing.
Flax seed sprouts are edible, with a slightly spicy flavour. Excessive consumption of flax seeds with inadequate water can cause bowel obstruction. Flaxseed, called ('Tisi' or 'Alsi') in northern India, has been roasted, powdered and eaten with boiled rice, a little water, and a little salt since ancient times in the villages.
Whole flax seeds are chemically stable, but ground flaxseed can go rancid at room temperature in as little as one week. Refrigeration and storage in sealed containers will keep ground flax from becoming rancid for a longer period; under conditions similar to those found in commercial bakeries, trained sensory panelists could not detect differences between bread made with freshly ground flax and bread made with milled flax stored for four months at room temperature. Milled flax is remarkably stable to oxidation when stored for nine months at room temperature if packed immediately without exposure to air and light and for 20 months at ambient temperatures under warehouse conditions.
See also Oil Seeds
Shipment / Storage / Risk factors
Linseed is shipped in bags or in bulk. Linseed is fairly hardy and can be stored in dry temperature conditions for a considerable time. Types of linseed vary considerably, according to the country of origin, both in size and colour, and linseed from the Near East will often be found to contain a high percentage of fine dust of a sandy nature. As this seed is used for the production of linseed oil and linseed cake and meal, damaged seed will produce a poor quality oil, dark in colour and high in free fatty acid content, and a cake or meal deficient in proteins.
Linseed is liable to heat and must be well ventilated. When subjected to humid unventilated conditions the seeds tend to coagulate and will deteriorate rapidly. Damage from moisture, heat and sweat, apart from being evidenced by coagulation, will also set up an internal discolouration of the seed, which should normally be white or near white in colour. To establish damage by over-heating, the seed should be crushed to disclose the interior colour, which in heat-damaged seeds will vary from a light brown to completely black in severe cases. Where seed has been damaged by water a musty odour is present, this varies in strength according to the extent of damage. Smell may not give much indication of deterioration unless it has been severe.
On discharge, note should be made of the moisture content of the seed, particularly any water damage. The moisture content can be exaggerated by heat or lack of ventilation during transit. This damage can be apparent on sight. Speed in protecting damaged seed is essential, as rapid deterioration can take place if left exposed to rain, or on a damp quay, and if moved from one place to another whilst unprotected. Losses in value can be avoided by modern methods of drying, such as kiln drying, etc., but unless quick action is taken linseed can deteriorate rapidly and might, through neglect, even deteriorate to the point of only having value as a fertiliser.
Quality degradation occurs in particular with excessively moist and excessively hot product and may be recognized from internal discoloration of the seed and a musty odour.
At a water content of 9 - 10.5%, linseed has a storage life of more than 12 months.
The most favourable time for shipment is shortly after harvest.
Linseed's elevated oil content (30-48%) promotes its tendency towards self-heating.
Of all oilseeds, linseed is the cargo which shifts most readily. Appropriate securing measures must therefore be taken when transporting the product as a bulk cargo (e.g. installation of additional bulkheads, bins and feeders).
Bagged 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.
In the case of maritime transport of bulk cargo, the IMSBC Code (International Maritime Solid Bulk Cargoes Code) must be complied with.