10.3 Chemistry of Aquatic Proteins
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until they reach the bloodstream, thus allowing them a better chance of eliciting their
bioactivities.
Algae and aquatic plants, therefore, can contribute to a more diversified protein
source for nutrition and other applications. Due to the increased rate of productivity
of aquatic plants and algae, they could contribute a more reliable source of plant type
proteins which can be used for nutrition and as bioactive agents.
10.4 Availability of Raw Materials
In 2016, 89,000 tonnes of microalgae was farmed across 11 countries of the world—
88,600 tonnes of this was from China. These include species such as Haematococcus
pluvialis, Nannochloropsis spp., Chlorella spp. and Spirulina spp. All are being
farmed in large, medium and small scales (FAO et al. 2018). While macroalgae
get a larger revenue from their food sales, microalgae are mostly sold as high-value
functional products. Therefore, despite the lower annual tonnes produced, microalgae
are valued at around a billion USD annually, compared to that of macroalgae at
6 billion USD (Bleakley and Hayes 2017).
The protein content in macroalgae is comparable to those found in animal-based
proteins and is higher than those found in land plants such as soybean, wheat and
legumes. Algae yield around 2.5–7.5 tonnes per hectare annually, while microalgae
yield 4–15 tonnes per hectare annually. These yields are rather high compared to
the conventional plant-based proteins such as wheat, soybeans and legumes which
yield 1.1, 0.6–1.2 and 1–2 tonnes per hectare annually (Van Krimpen et al. 2013).
Macroalgae and microalgae could contain similar or even more protein that terrestrial
plants typically used as protein source. Spirulina, a microalgae which have gained
much popularity as a nutrient source, could contain up to 63% protein per dry weight
(Toku¸ soglu and Üunal 2003). The red algae species Porphyra tenera contains up to
47% protein per dry weight (Fleurence 1999).
Protein content in any particular algae varies with factors such as growth season,
temperature, harvest period, region and nutrient content of water. The types of proteins present also vary. How different species react to particular changes in growth
condition in turn affects the types of proteins they metabolize. The algae make use of
these proteins to survive and function within its environment; therefore, the stimulus
it gets from these environments determines what protein it is prompted to produce.
These factors can be used to manipulate particular algae to produce desired type
of protein by controlling the growth environment. This requires an in-depth understanding of the correlation between environmental factors and the metabolism of the
specific species. For example, highest protein yield is obtained from the algae Kappaphycus alvarezii in August, November and February when studied over 12 months
from September 2004 to April 2006 in Northwestern India (Kumar et al. 2015).
Aquatic plants such as water fern, duckweed and water hyacinth contain relatively
moderate-to-high amounts of proteins. 28% protein content by dry weight has been
215
until they reach the bloodstream, thus allowing them a better chance of eliciting their
bioactivities.
Algae and aquatic plants, therefore, can contribute to a more diversified protein
source for nutrition and other applications. Due to the increased rate of productivity
of aquatic plants and algae, they could contribute a more reliable source of plant type
proteins which can be used for nutrition and as bioactive agents.
10.4 Availability of Raw Materials
In 2016, 89,000 tonnes of microalgae was farmed across 11 countries of the world—
88,600 tonnes of this was from China. These include species such as Haematococcus
pluvialis, Nannochloropsis spp., Chlorella spp. and Spirulina spp. All are being
farmed in large, medium and small scales (FAO et al. 2018). While macroalgae
get a larger revenue from their food sales, microalgae are mostly sold as high-value
functional products. Therefore, despite the lower annual tonnes produced, microalgae
are valued at around a billion USD annually, compared to that of macroalgae at
6 billion USD (Bleakley and Hayes 2017).
The protein content in macroalgae is comparable to those found in animal-based
proteins and is higher than those found in land plants such as soybean, wheat and
legumes. Algae yield around 2.5–7.5 tonnes per hectare annually, while microalgae
yield 4–15 tonnes per hectare annually. These yields are rather high compared to
the conventional plant-based proteins such as wheat, soybeans and legumes which
yield 1.1, 0.6–1.2 and 1–2 tonnes per hectare annually (Van Krimpen et al. 2013).
Macroalgae and microalgae could contain similar or even more protein that terrestrial
plants typically used as protein source. Spirulina, a microalgae which have gained
much popularity as a nutrient source, could contain up to 63% protein per dry weight
(Toku¸ soglu and Üunal 2003). The red algae species Porphyra tenera contains up to
47% protein per dry weight (Fleurence 1999).
Protein content in any particular algae varies with factors such as growth season,
temperature, harvest period, region and nutrient content of water. The types of proteins present also vary. How different species react to particular changes in growth
condition in turn affects the types of proteins they metabolize. The algae make use of
these proteins to survive and function within its environment; therefore, the stimulus
it gets from these environments determines what protein it is prompted to produce.
These factors can be used to manipulate particular algae to produce desired type
of protein by controlling the growth environment. This requires an in-depth understanding of the correlation between environmental factors and the metabolism of the
specific species. For example, highest protein yield is obtained from the algae Kappaphycus alvarezii in August, November and February when studied over 12 months
from September 2004 to April 2006 in Northwestern India (Kumar et al. 2015).
Aquatic plants such as water fern, duckweed and water hyacinth contain relatively
moderate-to-high amounts of proteins. 28% protein content by dry weight has been