13.4 Chemistry of Aquatic Starch
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size is not fully understood, it is hypothesized to be due to the timing of the granule
initiation process during starch synthesis within the cell. Other studies have established a relationship between the size of granules, period of formation and shape of
the granules and the amylose content of the starch (Ziegler et al. 2015).
The crystallinity of starch also varies for different sources. FTIR spectroscopy
showed that starch from green algae has a more amorphous structure, indicated by
more intense peaks at the wavelength of 1014.5 cm
−1 . Starches from green algae U.
ohnoi and potato starch show the same peaks for starch in the fingerprint region of
the FTIR and thus confirming that the starch from this aquatic source has identical
chemical composition to that of terrestrial-sourced starch. Decomposition temperature is another important parameter to consider in polymeric materials, and the
decomposition temperature informs processing and handling thermal parameters. At
283.7 °C, starch of green algae U. ohnois had began to degrade. This decomposition
temperature is similar to that of potato starch.
The physicochemical properties of the starch from aquatic source show many
similarities to those of common terrestrial sources such as rice, potato and cassava.
This similarity in the physical and chemical properties of starch from aquatic source
to those of terrestrial source suggests similar industrial applicabilities. Future studies
on toxicology and biocompatibility, it is required to confirm the possible range of
application to include direct consumption in food, cosmetics and medicine.
13.4.1 Biodegradation of Starch
Starch is a digestible polymer. It is broken down into its glucose units which can then
be converted into ATP to meet the energy requirement of the organisms. Looking
at the chemical structure of starch as shown in Fig. 13.1, it comprises of carbon,
hydrogen and oxygen, all of which can be safely absorbed into the environment.
Starch-producing organisms have biomechanisms for degradation of starch which
they accumulate and convert to energy when required. Humans also have biomechanics to degrade the starch they consume from plants and algae as food. Edibility depends on the safety of other molecules attached to the starch. Since starches
from terrestrial and aquatic sources are chemically identical, no distinction is made
between their respective degradation processes.
Starch-based products, such as bioplastics not consumed as food, need to be disposed of following their usage lifespan. One method of disposal is in landfill or buried
in soil or compost heaps where they degrade and serve as a carbon source for the
soil. Biodegradation of starch buried in soil in the forest occurs within several days.
Within 15 days, fungal hyphae colonize starch films and pronounced degradation of
starch granules is detectable by 45 days based on the observations using scanning
electron microscopy (SEM) (Lopez-Llorca and Valiente 1993).
The chemical properties of starch and the degradation conditions affect the degradation process. Properties such as crystallinity, molecular weight and granule size
affect the degradation rate and mechanism. Higher molecular weight starch degraded
295
size is not fully understood, it is hypothesized to be due to the timing of the granule
initiation process during starch synthesis within the cell. Other studies have established a relationship between the size of granules, period of formation and shape of
the granules and the amylose content of the starch (Ziegler et al. 2015).
The crystallinity of starch also varies for different sources. FTIR spectroscopy
showed that starch from green algae has a more amorphous structure, indicated by
more intense peaks at the wavelength of 1014.5 cm
−1 . Starches from green algae U.
ohnoi and potato starch show the same peaks for starch in the fingerprint region of
the FTIR and thus confirming that the starch from this aquatic source has identical
chemical composition to that of terrestrial-sourced starch. Decomposition temperature is another important parameter to consider in polymeric materials, and the
decomposition temperature informs processing and handling thermal parameters. At
283.7 °C, starch of green algae U. ohnois had began to degrade. This decomposition
temperature is similar to that of potato starch.
The physicochemical properties of the starch from aquatic source show many
similarities to those of common terrestrial sources such as rice, potato and cassava.
This similarity in the physical and chemical properties of starch from aquatic source
to those of terrestrial source suggests similar industrial applicabilities. Future studies
on toxicology and biocompatibility, it is required to confirm the possible range of
application to include direct consumption in food, cosmetics and medicine.
13.4.1 Biodegradation of Starch
Starch is a digestible polymer. It is broken down into its glucose units which can then
be converted into ATP to meet the energy requirement of the organisms. Looking
at the chemical structure of starch as shown in Fig. 13.1, it comprises of carbon,
hydrogen and oxygen, all of which can be safely absorbed into the environment.
Starch-producing organisms have biomechanisms for degradation of starch which
they accumulate and convert to energy when required. Humans also have biomechanics to degrade the starch they consume from plants and algae as food. Edibility depends on the safety of other molecules attached to the starch. Since starches
from terrestrial and aquatic sources are chemically identical, no distinction is made
between their respective degradation processes.
Starch-based products, such as bioplastics not consumed as food, need to be disposed of following their usage lifespan. One method of disposal is in landfill or buried
in soil or compost heaps where they degrade and serve as a carbon source for the
soil. Biodegradation of starch buried in soil in the forest occurs within several days.
Within 15 days, fungal hyphae colonize starch films and pronounced degradation of
starch granules is detectable by 45 days based on the observations using scanning
electron microscopy (SEM) (Lopez-Llorca and Valiente 1993).
The chemical properties of starch and the degradation conditions affect the degradation process. Properties such as crystallinity, molecular weight and granule size
affect the degradation rate and mechanism. Higher molecular weight starch degraded