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P. R. Gogate and S. M. Joshi
or open systems and can produce many high value chemicals with the help of photosynthesis. The ability to grow on wastewater and absorb carbon dioxide helps in
curbing environmental pollution along-with offering value addition. These aspects
make microalgae a value added feedstock shifting major focus of researchers on
commercialising their production with favourable economics (D’Alessandro and
Antoniosi Filho 2016) and also optimising the processes for recovery of value added
products. The overall processing of microalgae consists of different steps like cultivation in controlled conditions, harvesting and further processing with operations
like coagulation, filtration, centrifugation and foam fractionation depending on the
desired end product. Each product requires a specific pretreatment for the harvested
microalgae and extraction process further increasing the complexity of process.
Pigments from microalgae find application in food, cosmetic and pharmaceutical
industry. They are typically used as colouring agents, food supplements and possess
anti-inflammatory, anti-ageing, antioxidant and anticancer properties making them
a strong constituent in key medicines (Khanra et al. 2018). Recovery of pigments
consists of steps like cell disruption followed by selective extraction to obtain specific
pigments with exclusion of other intra cellular components. Pigments obtained from
microalgae are generally of three types, namely carotenoids, chlorophylls and phycobiliproteins. Astaxanthin, β-carotene and chlorophyll are the pigments which reportedly possess higher commercial markets. Following are brief details on different
classes of pigments available and recovered using extractions.
13.1.1 Carotenoids
Carotenoids are the most diverse and wide spread pigment, lipophilic in nature and
yellow, orange or red in colour. Carotenoids are mainly made up of C40 backbone
of isoprene units and are divided into two groups, namely carotenes and xanthophylls. Carotenoids are antioxidants and are sensitive to light, heat and oxygen
making them difficult to store and handle. Carotenoids function to absorb excess
light in visible spectrum and also play a role in energy transfer and cell protective
mechanisms (Gong and Bassi 2016). Carotenoids are mainly used as feed additives, food colorants and important ingredients in cosmetics and also recently there
is reported application in human health care. The major carotenoids available in
markets are astaxanthin, β-carotene, lycopene, canthaxanthin and lutein with astaxanthin and β-carotene accounting generally half the market. Astaxanthin comes with
a potential to enhance antibody production, as well as anti-aging and sun-proofing
characteristics and also exhibits stronger antioxidant activity than Vitamin E and
β-carotene. Microalgae, especially those strains belonging to chlorophyta, such as
Chlorella vulgaris, Chlorella zofingiensis, Dunaliella salina, Chlorella pyrenoidosa
and Haematococcus pluvialis are mainly employed in production of astaxanthin,
β-carotene, lutein, canthaxanthin and other carotenoids.
P. R. Gogate and S. M. Joshi
or open systems and can produce many high value chemicals with the help of photosynthesis. The ability to grow on wastewater and absorb carbon dioxide helps in
curbing environmental pollution along-with offering value addition. These aspects
make microalgae a value added feedstock shifting major focus of researchers on
commercialising their production with favourable economics (D’Alessandro and
Antoniosi Filho 2016) and also optimising the processes for recovery of value added
products. The overall processing of microalgae consists of different steps like cultivation in controlled conditions, harvesting and further processing with operations
like coagulation, filtration, centrifugation and foam fractionation depending on the
desired end product. Each product requires a specific pretreatment for the harvested
microalgae and extraction process further increasing the complexity of process.
Pigments from microalgae find application in food, cosmetic and pharmaceutical
industry. They are typically used as colouring agents, food supplements and possess
anti-inflammatory, anti-ageing, antioxidant and anticancer properties making them
a strong constituent in key medicines (Khanra et al. 2018). Recovery of pigments
consists of steps like cell disruption followed by selective extraction to obtain specific
pigments with exclusion of other intra cellular components. Pigments obtained from
microalgae are generally of three types, namely carotenoids, chlorophylls and phycobiliproteins. Astaxanthin, β-carotene and chlorophyll are the pigments which reportedly possess higher commercial markets. Following are brief details on different
classes of pigments available and recovered using extractions.
13.1.1 Carotenoids
Carotenoids are the most diverse and wide spread pigment, lipophilic in nature and
yellow, orange or red in colour. Carotenoids are mainly made up of C40 backbone
of isoprene units and are divided into two groups, namely carotenes and xanthophylls. Carotenoids are antioxidants and are sensitive to light, heat and oxygen
making them difficult to store and handle. Carotenoids function to absorb excess
light in visible spectrum and also play a role in energy transfer and cell protective
mechanisms (Gong and Bassi 2016). Carotenoids are mainly used as feed additives, food colorants and important ingredients in cosmetics and also recently there
is reported application in human health care. The major carotenoids available in
markets are astaxanthin, β-carotene, lycopene, canthaxanthin and lutein with astaxanthin and β-carotene accounting generally half the market. Astaxanthin comes with
a potential to enhance antibody production, as well as anti-aging and sun-proofing
characteristics and also exhibits stronger antioxidant activity than Vitamin E and
β-carotene. Microalgae, especially those strains belonging to chlorophyta, such as
Chlorella vulgaris, Chlorella zofingiensis, Dunaliella salina, Chlorella pyrenoidosa
and Haematococcus pluvialis are mainly employed in production of astaxanthin,
β-carotene, lutein, canthaxanthin and other carotenoids.