222
10 Aquatic Plants and Algae Proteins
10.6.5 Energy Consumption
Energy consumed depends on the method being used and the efficiency of the operating system. While ultrasound is being used, one study reports 0.4 kWh required per
liter of the biomass suspension being processed during the disruption of microalgal
cell (Keris-Sen et al. 2014). While physical method such as high-pressure homogenization is being used, energy to generate the amount of shear to disrupt the cell is
required.
Amount of heat required for extraction varies with the method being used. For
example, in extraction of water-soluble proteins from microalga N. gaditana where
cell disruption is carried out by high-pressure homogenization, the process of homogenization results in generation of heat from the friction forces and the exothermic
processes of cell disruption. This process thereby requires cooling to prevent overheating of the system (Safi et al. 2017). Proteins are prone to denaturation at elevated
temperature; therefore, the temperature should be kept as close to ambient as possible.
To achieve optimal cell disruption, a pressure of 150 GPa was sufficient. This resulted
in over 90% of the cells being disrupted in a single pass. This process required an
energy input of 0.44 kWh per kg of biomass. Repeated passes and increasing homogenization pressure did not result in higher percentage of cell disruption. Such studies
are necessary in terms of saving cost and time. Indeed, two passages would have
required an energy input of 7.5 kWh per kg resulting in only 3% increase in yield.
Energy also used in the additional unit operations is required to separate and purify.
Centrifugation of the suspension following cell disruption by physical, chemical or
enzyme treatment requires around 10,000 g for 10 min (Safi et al. 2017). Use of
enzymes reduces the heat energy required in the energy-demanding methods.
10.7 Applications
A variety of proteins can be found in algae, and some of these have distinct functions.
Some edible algae and aquatic plants are consumed in their whole form as food,
skin care, aquaculture or animal feed. Here we look at applications which involve
extracting protein from aquatic plants and algae for protein specific applications
which range from food to clinical applications. Some of the proteins described here
are not only limited to aquatic plants and algae and can be found in other terrestrial
plants and animals.
10.7.1 HIV Microbicides
A type of protein which is currently receiving attention in HIV prevention research
is lectins. Lectins are present in animals, microorganisms and terrestrial. They are
10 Aquatic Plants and Algae Proteins
10.6.5 Energy Consumption
Energy consumed depends on the method being used and the efficiency of the operating system. While ultrasound is being used, one study reports 0.4 kWh required per
liter of the biomass suspension being processed during the disruption of microalgal
cell (Keris-Sen et al. 2014). While physical method such as high-pressure homogenization is being used, energy to generate the amount of shear to disrupt the cell is
required.
Amount of heat required for extraction varies with the method being used. For
example, in extraction of water-soluble proteins from microalga N. gaditana where
cell disruption is carried out by high-pressure homogenization, the process of homogenization results in generation of heat from the friction forces and the exothermic
processes of cell disruption. This process thereby requires cooling to prevent overheating of the system (Safi et al. 2017). Proteins are prone to denaturation at elevated
temperature; therefore, the temperature should be kept as close to ambient as possible.
To achieve optimal cell disruption, a pressure of 150 GPa was sufficient. This resulted
in over 90% of the cells being disrupted in a single pass. This process required an
energy input of 0.44 kWh per kg of biomass. Repeated passes and increasing homogenization pressure did not result in higher percentage of cell disruption. Such studies
are necessary in terms of saving cost and time. Indeed, two passages would have
required an energy input of 7.5 kWh per kg resulting in only 3% increase in yield.
Energy also used in the additional unit operations is required to separate and purify.
Centrifugation of the suspension following cell disruption by physical, chemical or
enzyme treatment requires around 10,000 g for 10 min (Safi et al. 2017). Use of
enzymes reduces the heat energy required in the energy-demanding methods.
10.7 Applications
A variety of proteins can be found in algae, and some of these have distinct functions.
Some edible algae and aquatic plants are consumed in their whole form as food,
skin care, aquaculture or animal feed. Here we look at applications which involve
extracting protein from aquatic plants and algae for protein specific applications
which range from food to clinical applications. Some of the proteins described here
are not only limited to aquatic plants and algae and can be found in other terrestrial
plants and animals.
10.7.1 HIV Microbicides
A type of protein which is currently receiving attention in HIV prevention research
is lectins. Lectins are present in animals, microorganisms and terrestrial. They are