13 Process Intensification Aspects of Extraction …
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13.1.2 Chlorophylls
Chlorophylls are primary photosynthetic pigments widely found in plants and are
lipid soluble with low polarity. They play a critical role of light harvesting in photosynthesis, selective absorption of lights from blue and red regions and emission of
green colour. There are mainly two types of chlorophyll i.e. chlorophyll a and chlorophyll b with major occurrence of chlorophyll a in most microalgae. Replacement of
magnesium ion with copper ion in the extracted material results in stable chlorophyll,
namely chlorophyllin which is further used in commercial applications like body and
fecal odour controlling in geriatric patients and as dietary supplements. They are also
reported to have anti-mutagenic and anticancer properties (Halim et al. 2010).
13.1.3 Phycobiliproteins
Phycobiliproteins are water soluble pigments comprising a major portion of total
cell protein and act as a light collecting accessory during photosynthesis. They are
also used as natural dyes in food products and pharmaceutical industry. They are
commonly used as fluorescent markers in immunoassay and dyes for microscopy.
They also exhibit anticancer, antioxidant, antiviral, anti-inflammatory, neuro protective and anti-allergic properties. Red algae, namely Glaucophytas and Rhodophyta
are reported to produce 4 types of Phycobiliproteins i.e. phycocyanin, allophycocyanin, phycoerythrocyanin and phycoerythrin (D’Alessandro and Antoniosi Filho
2016).
We will now discuss the overall process of pigment production from microalgae
followed by brief on the conventional extraction process and subsequently details
of the intensified extraction processes. Processes like supercritical and subcritical
extraction, pulsed electric field (PEF) assisted extraction, pressurised liquid extraction, microwave assisted extraction (MAE), ultrasound assisted extraction (UAE),
high pressure homogenisation (HPH), etc. will be discussed with respect to their
application in pigment extraction process.
13.2 Process of Pigment Production
Process of pigment production starts from an initial phase of cultivating microalgae
with supply of specific nutrients and offering conditions required by different species
of microalgae for maximising the specific pigment content. Microalgae are generally grown in open pond (raceway ponds, natural ponds, circular ponds and inclined
systems) or closed systems (PBR-photobioreactor) (Joshi and Gogate 2018). Among
the different steps depicted in Fig. 13.1, harvesting is the next step following
311
13.1.2 Chlorophylls
Chlorophylls are primary photosynthetic pigments widely found in plants and are
lipid soluble with low polarity. They play a critical role of light harvesting in photosynthesis, selective absorption of lights from blue and red regions and emission of
green colour. There are mainly two types of chlorophyll i.e. chlorophyll a and chlorophyll b with major occurrence of chlorophyll a in most microalgae. Replacement of
magnesium ion with copper ion in the extracted material results in stable chlorophyll,
namely chlorophyllin which is further used in commercial applications like body and
fecal odour controlling in geriatric patients and as dietary supplements. They are also
reported to have anti-mutagenic and anticancer properties (Halim et al. 2010).
13.1.3 Phycobiliproteins
Phycobiliproteins are water soluble pigments comprising a major portion of total
cell protein and act as a light collecting accessory during photosynthesis. They are
also used as natural dyes in food products and pharmaceutical industry. They are
commonly used as fluorescent markers in immunoassay and dyes for microscopy.
They also exhibit anticancer, antioxidant, antiviral, anti-inflammatory, neuro protective and anti-allergic properties. Red algae, namely Glaucophytas and Rhodophyta
are reported to produce 4 types of Phycobiliproteins i.e. phycocyanin, allophycocyanin, phycoerythrocyanin and phycoerythrin (D’Alessandro and Antoniosi Filho
2016).
We will now discuss the overall process of pigment production from microalgae
followed by brief on the conventional extraction process and subsequently details
of the intensified extraction processes. Processes like supercritical and subcritical
extraction, pulsed electric field (PEF) assisted extraction, pressurised liquid extraction, microwave assisted extraction (MAE), ultrasound assisted extraction (UAE),
high pressure homogenisation (HPH), etc. will be discussed with respect to their
application in pigment extraction process.
13.2 Process of Pigment Production
Process of pigment production starts from an initial phase of cultivating microalgae
with supply of specific nutrients and offering conditions required by different species
of microalgae for maximising the specific pigment content. Microalgae are generally grown in open pond (raceway ponds, natural ponds, circular ponds and inclined
systems) or closed systems (PBR-photobioreactor) (Joshi and Gogate 2018). Among
the different steps depicted in Fig. 13.1, harvesting is the next step following