196
9 Laminarins
was cultivated in aquaculture globally. The live weight contains around 45% moisture prior to natural drying in storage. After drying at room temperature, the algae
used as feedstock are generally around 25% moisture content (Konda et al. 2015).
This figure excluded L. japonica species, and this is one of the main Phaeophyceae
which acts as a major source of laminarin. Production of L. japonica in 2016 was
8,219,000 tonnes cultivated using aquaculture. China is the lead producers of algae
followed by Indonesia producing live weight of 14,387,000 and 11,631,000 tonnes,
respectively, in 2016. The figures from 2005 to 2016 show a continuous rise in the
production algae from different countries, with some few exceptional cases where a
drop in production is experienced as a result of isolated cases. For example, a drop
in production of Undaria pinnatifida species is reported from 2014 to 2015 to 2016,
where the cultivated amount was 2,359,000, 2,297,000 and 22,070,000, respectively.
Algae cultivated using aquaculture is given more attention here since 96.5% of the
global production of algae is from aquaculture. Although a small amount of algae
obtained from wild stock and some countries have implemented policies to conserve
the population of certain species of algae in the areas where they grow naturally
and contribute significantly to the aquatic ecosystem, aquaculture remains the main
method of cultivating algae for large-scale production for either direct consumption
as food or for extraction of biocompounds.
Although alginate is the most common biopolymer extracted from brown algae,
processes have been presented which allow the extraction of laminarin, fucoidan and
alginate from brown algae in a single process. Such developments make it possible
to optimize the utilization of the brown algae resource and minimize the component
which is discarded as waste. Furthermore, since the species of brown algae required
for alginate production are the same which are used for laminarin production, the
availability of brown algae for laminarin production is further maintained as it is a
raw material for multiple purposes.
9.5 Extraction of Laminarin
As a soluble polysaccharide, laminarin can be extracted by dissolving out in a suitable
solvent at specific conditions within which it is soluble. Laminarin is extracted from
the thallus of the brown algae. Extraction method commonly used for laminarin is
summarized in Fig. 9.3.
The highly branched laminarins are soluble in both hot water and cold water, while
the laminarins with less branching are only soluble in hot water. This difference in
solubility can be used as a basis for obtaining laminarin of desired level of branching.
Extraction is generally achieved by treatment with hot or cold acids or calcium
chloride. Acids commonly used are hydrochloric acid or sulfuric acid. Laminarin
is then precipitated with alcohol. The extract can then be redispersed in a suitable
solvent and then purified. Most common purification presented in many research
studies is the ultrafiltration and dialysis.
9 Laminarins
was cultivated in aquaculture globally. The live weight contains around 45% moisture prior to natural drying in storage. After drying at room temperature, the algae
used as feedstock are generally around 25% moisture content (Konda et al. 2015).
This figure excluded L. japonica species, and this is one of the main Phaeophyceae
which acts as a major source of laminarin. Production of L. japonica in 2016 was
8,219,000 tonnes cultivated using aquaculture. China is the lead producers of algae
followed by Indonesia producing live weight of 14,387,000 and 11,631,000 tonnes,
respectively, in 2016. The figures from 2005 to 2016 show a continuous rise in the
production algae from different countries, with some few exceptional cases where a
drop in production is experienced as a result of isolated cases. For example, a drop
in production of Undaria pinnatifida species is reported from 2014 to 2015 to 2016,
where the cultivated amount was 2,359,000, 2,297,000 and 22,070,000, respectively.
Algae cultivated using aquaculture is given more attention here since 96.5% of the
global production of algae is from aquaculture. Although a small amount of algae
obtained from wild stock and some countries have implemented policies to conserve
the population of certain species of algae in the areas where they grow naturally
and contribute significantly to the aquatic ecosystem, aquaculture remains the main
method of cultivating algae for large-scale production for either direct consumption
as food or for extraction of biocompounds.
Although alginate is the most common biopolymer extracted from brown algae,
processes have been presented which allow the extraction of laminarin, fucoidan and
alginate from brown algae in a single process. Such developments make it possible
to optimize the utilization of the brown algae resource and minimize the component
which is discarded as waste. Furthermore, since the species of brown algae required
for alginate production are the same which are used for laminarin production, the
availability of brown algae for laminarin production is further maintained as it is a
raw material for multiple purposes.
9.5 Extraction of Laminarin
As a soluble polysaccharide, laminarin can be extracted by dissolving out in a suitable
solvent at specific conditions within which it is soluble. Laminarin is extracted from
the thallus of the brown algae. Extraction method commonly used for laminarin is
summarized in Fig. 9.3.
The highly branched laminarins are soluble in both hot water and cold water, while
the laminarins with less branching are only soluble in hot water. This difference in
solubility can be used as a basis for obtaining laminarin of desired level of branching.
Extraction is generally achieved by treatment with hot or cold acids or calcium
chloride. Acids commonly used are hydrochloric acid or sulfuric acid. Laminarin
is then precipitated with alcohol. The extract can then be redispersed in a suitable
solvent and then purified. Most common purification presented in many research
studies is the ultrafiltration and dialysis.