13.5 Floridean Starch
297
contained amylose (McCracken and Cain 1980), it was later found that floridean
starch contains only amylopectin and is limited to a specific group of red algae so
named as Florideophyceae (Dauvillee et al. 2009). The other group of red algae,
Bangiophyceae, does not contain floridean starch (McCracken and Cain 1980). The
composition of floridean starch can be up to 80% in red algae.
Floridean starch extracted from red algae in one study show granules structures of
mostly spherical orientation, although some other granule shapes are also observed
(Yu et al. 2002). The granule length was measured to be in the range 1.7–3.4 µm
and was species dependent. For example, the red algae species G. chilensis has an
average granule size of 3.4 µm while that from the red algae Gracilariopsis sp. had
an average granule size of 1.7 µm.
Although floridean starch is relatively newer concept, the Florideophyceae red
algae are widely commercially explored for food and extraction of agar and carrageenan. There is therefore room to integrate the extraction of floridean starch
alongside the extraction of these other polymers from the red algae. The highly
branched structure of floridean starch means they are less stable and more easily
hydrolyzed than linear form. This has significance in the area of biofuel production.
13.6 Extraction Process
Extraction of starch from the natural aquatic source generally involves separation
from the other components such as lignin, cellulose, proteins, lipids and other components. In plants and algae with no lignin, the complexity of the extraction process
is reduced to a significant extent. Starch can also be obtained as a by-product of
other extraction processes. It is more efficient to be able to obtain multiple biopolymers from the same source, particularly one that can be done in a single process
concurrently.
In the following subsections, we review the extraction processes for starch from
various aquatic sources. Some similarity exists in some of these processes, while the
variations should have some significant economic and environmental implications.
The variations in the processes are in most cases which are due to the difference in
the structural composition of the plant or algae feedstock.
13.6.1 Extraction of Starch from Microalgae
Microalgae are an important source of biopolymers, and one of the reasons for this
is the ability to control and influence the metabolism of microalgae compared to
macroalgae. Here, the extraction of starch from the microalgae C. sorokiniana is
used as an example of the extraction of starch from microalgae. The microalgae
are cultivated in a photobioreactor. It is also important to consider the process for
extraction of starch from microalgae harvested from the open aquatic ecosystem as
297
contained amylose (McCracken and Cain 1980), it was later found that floridean
starch contains only amylopectin and is limited to a specific group of red algae so
named as Florideophyceae (Dauvillee et al. 2009). The other group of red algae,
Bangiophyceae, does not contain floridean starch (McCracken and Cain 1980). The
composition of floridean starch can be up to 80% in red algae.
Floridean starch extracted from red algae in one study show granules structures of
mostly spherical orientation, although some other granule shapes are also observed
(Yu et al. 2002). The granule length was measured to be in the range 1.7–3.4 µm
and was species dependent. For example, the red algae species G. chilensis has an
average granule size of 3.4 µm while that from the red algae Gracilariopsis sp. had
an average granule size of 1.7 µm.
Although floridean starch is relatively newer concept, the Florideophyceae red
algae are widely commercially explored for food and extraction of agar and carrageenan. There is therefore room to integrate the extraction of floridean starch
alongside the extraction of these other polymers from the red algae. The highly
branched structure of floridean starch means they are less stable and more easily
hydrolyzed than linear form. This has significance in the area of biofuel production.
13.6 Extraction Process
Extraction of starch from the natural aquatic source generally involves separation
from the other components such as lignin, cellulose, proteins, lipids and other components. In plants and algae with no lignin, the complexity of the extraction process
is reduced to a significant extent. Starch can also be obtained as a by-product of
other extraction processes. It is more efficient to be able to obtain multiple biopolymers from the same source, particularly one that can be done in a single process
concurrently.
In the following subsections, we review the extraction processes for starch from
various aquatic sources. Some similarity exists in some of these processes, while the
variations should have some significant economic and environmental implications.
The variations in the processes are in most cases which are due to the difference in
the structural composition of the plant or algae feedstock.
13.6.1 Extraction of Starch from Microalgae
Microalgae are an important source of biopolymers, and one of the reasons for this
is the ability to control and influence the metabolism of microalgae compared to
macroalgae. Here, the extraction of starch from the microalgae C. sorokiniana is
used as an example of the extraction of starch from microalgae. The microalgae
are cultivated in a photobioreactor. It is also important to consider the process for
extraction of starch from microalgae harvested from the open aquatic ecosystem as