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6 Carrageenans
seaweed species K. alvarezii and E. denticulatum have become the more common raw material for carrageenan production (McHugh 2003). For more diverse
range of applications, there are continuous efforts to explore the variety of structural forms of carrageenan and this involves uses of a broad range of species which
serve as sources of various forms of carrageenan. These include H. musciformis,
M. laminaroides, S. crispata, B. gelatinum, C. crispus, E. denticulatum, Eucheuma
gelatinase, E. spinosum, G. canaliculata and G. skottsbergii (McHugh 2003).
Red seaweed, which serves as the source of carrageenan, is primarily used as
food as it makes up a sizeable part of Asian cuisine which is adopted across different
parts of the world. In cold waters, red seaweed species of economic importance such
as Palmaria palmata can be sourced from cold regions such as Canada, Iceland,
Ireland and southern Chile, while in warmer waters they can be found in areas such
as Morocco, Portugal, the Philippines, and Indonesia.
Most common species of red seaweed that is harvested for food is the Porphyra
which is more commonly called nori or laver. It is commonly used in preparation for
sushi, a Japanese delicacy which comprises raw fish and boiled rice wrapped in red
seaweed which has been processed into thin sheets. The seaweed plays a structural
role as an edible food wrap and also has significant nutritional value.
A large proportion of the red seaweed harvested globally is from cultivation of red
seaweed as seaweed growing naturally in the wild is insufficient to meet increasing
demands. The cost of harvesting from wild is also higher, and in some cases access
is limiting. Cultivation in tanks requires a good understanding of the life cycle and
required growth conditions of the particular species. Republic of Korea, China and
Japan are some of the major large-scale producers of red seaweed. Red seaweed nori
is one of the most highly priced seaweeds which is valued at 1200 USD per wet
tonne, relative to, for example, brown seaweeds which are valued at 610–530 USD
per wet tonne.
The type of carrageenan present in each species of red algae varies. Some species
contain almost only one form of carrageenan, while some species contain a mixture
of two different types of carrageenan. These mixtures are referred to as hybrids.
A species of red seaweed known as K. alvarezii, for example, contains almost
entirely kappa carrageenan, and another species called E. denticulatum (E. spinosum)
contains almost entirely iota carrageenan. Species which contain hybrids include
Chondrus which contain a mixture of kappa and lambda. A large fraction of the red
seaweeds used for carrageenan production are sourced from the Philippines. Improvement in seaweed harvesting technology has led to red seaweed cultivation spreading
to warmer regions such as Tanzania and Indonesia. Seaweeds which can be grown
vegetatively are preferred for commercial carrageenan production as those requiring sexual reproductive cycles are more cost intensive making it non-economical
as raw materials for carrageenan production. For seaweeds sold as food, the cost
can be recovered more easily since very little further value addition occurs in the
product preparation. However for use as raw materials for carrageenan production,
further cost is involved in the extraction and purification of carrageenan such that it is
paramount to minimize the cost of raw material, thus making vegetative cultivation
a more favorable option.
6 Carrageenans
seaweed species K. alvarezii and E. denticulatum have become the more common raw material for carrageenan production (McHugh 2003). For more diverse
range of applications, there are continuous efforts to explore the variety of structural forms of carrageenan and this involves uses of a broad range of species which
serve as sources of various forms of carrageenan. These include H. musciformis,
M. laminaroides, S. crispata, B. gelatinum, C. crispus, E. denticulatum, Eucheuma
gelatinase, E. spinosum, G. canaliculata and G. skottsbergii (McHugh 2003).
Red seaweed, which serves as the source of carrageenan, is primarily used as
food as it makes up a sizeable part of Asian cuisine which is adopted across different
parts of the world. In cold waters, red seaweed species of economic importance such
as Palmaria palmata can be sourced from cold regions such as Canada, Iceland,
Ireland and southern Chile, while in warmer waters they can be found in areas such
as Morocco, Portugal, the Philippines, and Indonesia.
Most common species of red seaweed that is harvested for food is the Porphyra
which is more commonly called nori or laver. It is commonly used in preparation for
sushi, a Japanese delicacy which comprises raw fish and boiled rice wrapped in red
seaweed which has been processed into thin sheets. The seaweed plays a structural
role as an edible food wrap and also has significant nutritional value.
A large proportion of the red seaweed harvested globally is from cultivation of red
seaweed as seaweed growing naturally in the wild is insufficient to meet increasing
demands. The cost of harvesting from wild is also higher, and in some cases access
is limiting. Cultivation in tanks requires a good understanding of the life cycle and
required growth conditions of the particular species. Republic of Korea, China and
Japan are some of the major large-scale producers of red seaweed. Red seaweed nori
is one of the most highly priced seaweeds which is valued at 1200 USD per wet
tonne, relative to, for example, brown seaweeds which are valued at 610–530 USD
per wet tonne.
The type of carrageenan present in each species of red algae varies. Some species
contain almost only one form of carrageenan, while some species contain a mixture
of two different types of carrageenan. These mixtures are referred to as hybrids.
A species of red seaweed known as K. alvarezii, for example, contains almost
entirely kappa carrageenan, and another species called E. denticulatum (E. spinosum)
contains almost entirely iota carrageenan. Species which contain hybrids include
Chondrus which contain a mixture of kappa and lambda. A large fraction of the red
seaweeds used for carrageenan production are sourced from the Philippines. Improvement in seaweed harvesting technology has led to red seaweed cultivation spreading
to warmer regions such as Tanzania and Indonesia. Seaweeds which can be grown
vegetatively are preferred for commercial carrageenan production as those requiring sexual reproductive cycles are more cost intensive making it non-economical
as raw materials for carrageenan production. For seaweeds sold as food, the cost
can be recovered more easily since very little further value addition occurs in the
product preparation. However for use as raw materials for carrageenan production,
further cost is involved in the extraction and purification of carrageenan such that it is
paramount to minimize the cost of raw material, thus making vegetative cultivation
a more favorable option.