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Alexandra Galetovi´ c C. and L. Dufossé
The content of PBPs decreases to pH very acidic (2–4) and alkaline pH 8–12, this
is because changes in pH alter the electrostatic properties and hydrogen bonds of
the protein-producing changes in the structure of the chromophore and apoprotein
(Rastogi et al. 2015).
In this sense, the stability of phycocyanin is greater than 4 °C and in darkness
(Choi and Lee 2018). PC Anabaena fertilissima PUPPCC 410.5 and PE of Lyngbya
arboricola to terrestrial desiccation cyanobacterium are more stable lyophilized than
in solution (Tripathi et al. 2007 and Kaur et al. 2019). The half-life of dry lyophilized
PC is 100 days stored at 4 °C in darkness. PC is highly unstable at 42 °C in light
decreased 50% in 4 days. The phycocyanin of Anabaena fertilissima was added to
dairy milk products such as milk and yogurt, stable for 6–9 days at 4 °C in the dark
and maintained its antioxidant properties (Kaur et al. 2019).
Another way to preserve and store phycocyanin from the PC of Spirulina sp. strain
LEB-18 is by drying system known as spouted bed drying (at 80 °C) or tray drying
(at 55 °C) with both techniques the PC had high stability measured as PC content,
color, and antioxidant activity (Larrosa et al. 2018).
Interestingly, temperature can induce changes in the content of each of the phycobiliproteins, in a similar way as in the case of complementary chromatic adaptation, in
which the type of wavelength that is influenced by cyanobacterial cultures produces
increases in PE or PC. The thermostable cyanobacterium Oscillatoria sp. N9DM
when grown at 30–42 °C produces more PE, but if the cultures are grown at 55 °C
they produce only PC (Singh et al. 2012). The latter is a simple way to enrich cultures
with the phycobiliprotein of interest.
22.4 Food Grade Phycobiliproteins
The term food grade is used in the food industry to refer to the quality of the ingredient
(phycobiliprotein) measured in terms of concentration and purity in order to ensure
the innocuousness of the pigment. In phycobiliproteins the food grade is calculated
from the absorbance ratios at the maximum absorption of each phycobiliprotein (PC
at 620 nm, PE at 550 nm) in relation to the absorbance of total proteins at 280 nm.
Figure 22.1 shows some examples of the application of phycobiliproteins in foods.
The absorbance ratios for PC A620/A280 between 0.7 and 4 are considered food,
> 4 reactive and analytical grade. The A620/A280 ratio of 2 is accepted in the food
industry (Kuddus et al. 2013; Munawaroh et al. 2018). Classical biochemical techniques such as precipitation with ammonium sulfate and ion exchange chromatography, commonly used in the purification of phycobiliproteins, allow these pigments
to be obtained with reactive and analytical grade (Table 22.1).
Alexandra Galetovi´ c C. and L. Dufossé
The content of PBPs decreases to pH very acidic (2–4) and alkaline pH 8–12, this
is because changes in pH alter the electrostatic properties and hydrogen bonds of
the protein-producing changes in the structure of the chromophore and apoprotein
(Rastogi et al. 2015).
In this sense, the stability of phycocyanin is greater than 4 °C and in darkness
(Choi and Lee 2018). PC Anabaena fertilissima PUPPCC 410.5 and PE of Lyngbya
arboricola to terrestrial desiccation cyanobacterium are more stable lyophilized than
in solution (Tripathi et al. 2007 and Kaur et al. 2019). The half-life of dry lyophilized
PC is 100 days stored at 4 °C in darkness. PC is highly unstable at 42 °C in light
decreased 50% in 4 days. The phycocyanin of Anabaena fertilissima was added to
dairy milk products such as milk and yogurt, stable for 6–9 days at 4 °C in the dark
and maintained its antioxidant properties (Kaur et al. 2019).
Another way to preserve and store phycocyanin from the PC of Spirulina sp. strain
LEB-18 is by drying system known as spouted bed drying (at 80 °C) or tray drying
(at 55 °C) with both techniques the PC had high stability measured as PC content,
color, and antioxidant activity (Larrosa et al. 2018).
Interestingly, temperature can induce changes in the content of each of the phycobiliproteins, in a similar way as in the case of complementary chromatic adaptation, in
which the type of wavelength that is influenced by cyanobacterial cultures produces
increases in PE or PC. The thermostable cyanobacterium Oscillatoria sp. N9DM
when grown at 30–42 °C produces more PE, but if the cultures are grown at 55 °C
they produce only PC (Singh et al. 2012). The latter is a simple way to enrich cultures
with the phycobiliprotein of interest.
22.4 Food Grade Phycobiliproteins
The term food grade is used in the food industry to refer to the quality of the ingredient
(phycobiliprotein) measured in terms of concentration and purity in order to ensure
the innocuousness of the pigment. In phycobiliproteins the food grade is calculated
from the absorbance ratios at the maximum absorption of each phycobiliprotein (PC
at 620 nm, PE at 550 nm) in relation to the absorbance of total proteins at 280 nm.
Figure 22.1 shows some examples of the application of phycobiliproteins in foods.
The absorbance ratios for PC A620/A280 between 0.7 and 4 are considered food,
> 4 reactive and analytical grade. The A620/A280 ratio of 2 is accepted in the food
industry (Kuddus et al. 2013; Munawaroh et al. 2018). Classical biochemical techniques such as precipitation with ammonium sulfate and ion exchange chromatography, commonly used in the purification of phycobiliproteins, allow these pigments
to be obtained with reactive and analytical grade (Table 22.1).