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6 Carrageenans
is mainly attributed to its use for its rheological properties, further modifications
of carrageenan result in the form of carrageenans with important bioactivities thus
increasing the potential market value of carrageenans to beyond just food additives.
Carrageenans are classified as galactans which are generally characterized by
the galactose repeating units. It is one of three hydrophilic phycocolloids obtained
from algae, and it is a sulfated polysaccharide found in the cell wall of red algae
species such as Kappaphycus alvarezii (Manuhara et al. 2016), Hypnea musciformis
(Souza et al. 2018) and Palisada flagellifera (Ferreira et al. 2012). Carrageenan has
relatively well-established application in the food industry where it is used for texture
modification and stabilization.
The subsequent sections in this chapter discuss the occurrence of carrageenan
in nature, the abundance of the raw material for production of carrageenan and
the present state of these resources as well as past trends. A couple of extraction
methods are reviewed to give the reader an idea of what is required to produce
this aquatic biopolymer. As naturally sourced products received increasing attention
from consumers, researchers and producers, it is important to review the environmental implications of these products beyond just the fact that they are biodegradable
and renewable. A section in this chapter is therefore dedicated to the environmental implications of the process of producing carrageenans and discusses some key
aspects.
6.2 Occurrence in Nature
Carrageenan is present in nature as one of the sulfated polysaccharides of red algae
(Rhodophyta). It is a component of the cell wall where it plays a structural role alongside the other cell wall polysaccharides. Red algae species which contain carrageenan
include species such as K. alvarezii (Manuhara et al. 2016), H. musciformis (Souza
et al. 2018), P. flagellifera (Ferreira et al. 2012), Gigartina skottsbergii (Gonçalves
et al. 2005), Eucheuma spinosum (Ghani et al. 2019). Prior to carrageenan being
known as the sulfated polysaccharide phycocolloid of red algae, carrageenan has
been used for its gelling properties in its whole form as seaweed as far back as 1905
where the Chondrus crispus commonly referred to as Irish moss is used as a gelling
agent in recipes such as blancmange (Smith 1905). Carrageenans have been identified as the gelatinous extract obtained from boiling of the red algae species C. crispus
in hot water (Stanford 1862). Carrageenan-producing species of red algae of genus
Eucheuma have documented use for medicinal, food and adhesive purposes in the
far east regions dating back to the early 1950s (Eisses 1952; Zaneveld 1959; Stanley
1987).
In the wild, red algae such as K. alvarezii are abundant in places such as
Karimun Jawa Islands in town of Jepara located in Central Java, Indonesia, and
in Ubatuba, São Paulo in Brazil (Gonçalves et al. 2005) and species such as
H. musciformis are abundant in regions like Flecheiras Beach in Ceara, Brazil
(Souza et al. 2018). H. musciformis is valued for its kappa carrageenan content
6 Carrageenans
is mainly attributed to its use for its rheological properties, further modifications
of carrageenan result in the form of carrageenans with important bioactivities thus
increasing the potential market value of carrageenans to beyond just food additives.
Carrageenans are classified as galactans which are generally characterized by
the galactose repeating units. It is one of three hydrophilic phycocolloids obtained
from algae, and it is a sulfated polysaccharide found in the cell wall of red algae
species such as Kappaphycus alvarezii (Manuhara et al. 2016), Hypnea musciformis
(Souza et al. 2018) and Palisada flagellifera (Ferreira et al. 2012). Carrageenan has
relatively well-established application in the food industry where it is used for texture
modification and stabilization.
The subsequent sections in this chapter discuss the occurrence of carrageenan
in nature, the abundance of the raw material for production of carrageenan and
the present state of these resources as well as past trends. A couple of extraction
methods are reviewed to give the reader an idea of what is required to produce
this aquatic biopolymer. As naturally sourced products received increasing attention
from consumers, researchers and producers, it is important to review the environmental implications of these products beyond just the fact that they are biodegradable
and renewable. A section in this chapter is therefore dedicated to the environmental implications of the process of producing carrageenans and discusses some key
aspects.
6.2 Occurrence in Nature
Carrageenan is present in nature as one of the sulfated polysaccharides of red algae
(Rhodophyta). It is a component of the cell wall where it plays a structural role alongside the other cell wall polysaccharides. Red algae species which contain carrageenan
include species such as K. alvarezii (Manuhara et al. 2016), H. musciformis (Souza
et al. 2018), P. flagellifera (Ferreira et al. 2012), Gigartina skottsbergii (Gonçalves
et al. 2005), Eucheuma spinosum (Ghani et al. 2019). Prior to carrageenan being
known as the sulfated polysaccharide phycocolloid of red algae, carrageenan has
been used for its gelling properties in its whole form as seaweed as far back as 1905
where the Chondrus crispus commonly referred to as Irish moss is used as a gelling
agent in recipes such as blancmange (Smith 1905). Carrageenans have been identified as the gelatinous extract obtained from boiling of the red algae species C. crispus
in hot water (Stanford 1862). Carrageenan-producing species of red algae of genus
Eucheuma have documented use for medicinal, food and adhesive purposes in the
far east regions dating back to the early 1950s (Eisses 1952; Zaneveld 1959; Stanley
1987).
In the wild, red algae such as K. alvarezii are abundant in places such as
Karimun Jawa Islands in town of Jepara located in Central Java, Indonesia, and
in Ubatuba, São Paulo in Brazil (Gonçalves et al. 2005) and species such as
H. musciformis are abundant in regions like Flecheiras Beach in Ceara, Brazil
(Souza et al. 2018). H. musciformis is valued for its kappa carrageenan content