Since ancient times, especially in China, the Korean and Japanese peninsulas. In addition to emigrating to other regions, the naturalities of these countries have led to this use of seaweed to their new countries, so that products based on salad, dried and fresh seaweed can be found all over the world. This is the commercial base of the marine algae food industry.
Coastal poblaciones from many countries also consume seaweed, sometimes as part of life forms based on a subsistence economy and others as a common ingredient in certain types of salads, especially in Hawaii and the warmer countries of South Asia, such as eg Indonesia, Malaysia, Philippines and Thailand. These products are collected and sold locally, and do not count on their volume or value. The three most important marine algae used as human food in various species of Porphyra (common name in Japan and nori),
Laminaria (kombu) and Undaria (wakame).
In the last years Porphyra has figured in Japanese statistics on fishing as the third catch in order of importance. These three algae are obtained from the beginning of wild species, but at present they are only possible to cover the demand using methods of cultivation in large scale. Porphyra is classified as a red alga, even though Laminaria y Undaria is brown algae. The life cycle of Porphyra is complete and it was only explained in the decade of 1950 by a British ficologist.
- This is the place for a rapid expansion of the norm industry, first in Japan and later in China and the Republic of
- Korea. The nori is sold in packages (of 30 g) of thin plates, from 10 to 12 cm2, usually without cooking or
- slightly horned, and used to form the outer wrapping of the sushi. Sometimes cooked and salted as an aperitif or sprinkled over rice or beans. It has a high content of valuable edible proteins.
It is estimated that the annual production is 90 000 tonnes of dry weight and that its value amounts to 1 460 million US dollars. Laminaria species were cultivated for the first time in Japan, but in the 1950s Chinese scientists succeeded in reducing the time of cultivation from two years to one soil, and the production of China grew up to 1.5 million tons of algae annually. fresh. The major part of this production is dried and consumed as kombu in the coastal provinces, and the rest is used to produce alginate.
However, the cost of cultivation is high and even the price you get for your food (US $ 3,000 per dry weight ton) makes up for this difference, not being competitive in an open alginate market. the cost of raw material must be around US $ 500 per ton of dry weight, so the china alginate industry does not need to use wild species, even imported. The kombu is used in a wide variety of soup plates, as an ingredient in a Japanese upholstery, to make it short and even.
It is grown on a large scale over all of Japan and China,
and to a lesser extent in the Republic of Korea. The world production is estimated to be more than a million tons of dry weight, with a value of 3 000 million US dollars. Undaria is especially appreciated in the Republic of Korea, where it is grown on a larger scale than in other countries. It is a less heavy and more delicate seaweed than kombu.
It is prepared and sold in the form of a blanqueado product and a salad, which is stored at -10 degrees Celsius before being sold. It is consumed desalándolo in water and it is used above all in soups; in the Republic of Korea more wakame is used, with the result that a much bigger soup is obtained than in Japan. Some products made with wakame are marketed as instant foods. The production of
Undaria, in its largest part cultivated but also in wild part, is of 33,000 tons of dry weight, and its value amounts to 230 million US dollars. In the last decade, some French research and development institutions have made considerable efforts to produce edible seaweed products with the introduction of European diet and market. 3.2 Seaweed as a source of hydrocolloidsThe cell walls of marine algae contain wide-span polysaccharides,
Which, due to the flexibility of the algae
and the algae, allows them to adapt to the variety of movements of the water in which they grow. For example, some brown algae grow subject to rocks in very turbulent waters, so there is a great flexibility to survive; these algae contain a greater degree of this type of polysaccharide than brown algae that grow in calm waters.
- These polysaccharides are called hydrocolloids because when they dissolve in water they cause colloidal properties to dissolve. The polysaccharides of other sources,
- such as terrestrial plants, behave in a similar way, because sometimes the term “ficocoloides” is used to distinguish hydrocolloids derived
- from seaweed (from phytocology, seaweed studio, including seaweed). When dispersed in water, hydrocolloids increase viscosity, so they have many applications as thickening agents. Under certain conditions, they are also gels,
and this property is useful for other applications. The colloidal properties of algae allow them to be used with other fines in which their mode of action is less easy to determine; for example, the hydrocolloid derived from the brown algae suele añadirse al helado, to prevent the formation of crystals of ice when it partially melts and freezes (in the supermarket way home).
The hydrocolloids of commercial importance obtained from sea algae are alginate, agar and carrageenan. The polysaccharide containing brown algae is alginic acid, present in the form of sodium, potassium, magnesium and calcium suspensions (scientifically speaking, alginic acid is a carboxylic acid). The seaweed contains a variety of polysaccharides,