16 Chlorophylls as Food Additives
393
health benefits for humans, such as antioxidant, antimutagenic, antigenotoxic, and
anti-inflammatory activities (Pérez-Gálvez et al. 2017).
Consequently, the use of these molecules as an additive of colour in food is strictly
regulated in the United States, the European Union, and many other countries in
the world, such as China, India, Canada, Australia, New Zealand, Brazil, and Japan.
Currently, commercially available chlorophyll compounds consist of structures basically related to chlorophylls a and b (Rodriguez-Amaya 2019), being emerging the
exploration of no explored structures as species c, d, and f and their derivatives as
alternatives to natural green dyes. Additionally, as a colour stabilization strategy,
microalgae biomass appears to be a potential alternative as a functional ingredient
with green colouring properties as secondary effect.
Thus, the purpose of this chapter is to provide a comprehensive overview of the
application of chlorophylls and their compounds derived in foods, with emphasis
on microalgae as potential sources for obtaining these compounds. Moreover, it is
revised chemical structure of chlorophylls, distribution, biological properties of these
compounds, including regulatory milestones in force in different countries for your
application.
16.2 Structure and Distribution Chlorophylls
Natural chlorophylls are the most abundant pigments in nature, occurring more than
100 different structures, found in oxygenic photosynthetic organisms such as higher
plants, microalgae, algae, and some bacteria (Lanfer-Marquez and Borrmann 2009;
Pérez-Gálvez et al. 2017).
The structure of chlorophylls is tetrapyrrole with a system of coplanar conjugated
double bonds that forms the chromophore with delocalization of electron density in
π orbitals, formed from one magnesium atom as the central metal and a phytyl chain
(C 20 H 40 ) esterifying the propionic acid at C17 3 , gives chlorophyll a hydrophobic
character, as shown in Fig. 16.1 (Yilmaz and Gökmen 2016).
Chlorophylls a, b, and c were reported in the nineteenth century (Govindjee 2004),
chlorophyll d was identified more than 70 years after the other chlorophylls (Manning
and Strain 1943), and chlorophyll f was reported in 67 years after (Chen et al. 2010).
However, the major chlorophylls in food additives are chlorophyll a and chlorophyll
b (Viera et al. 2019).
Chlorophyll a (Fig. 16.2a, b) are different at position C 7 , where chlorophyll a
is composed of methyl group and chlorophyll b is composed of formyl group. The
chlorophylls d and f are similar to chlorophyll a, where chlorophyll d (Fig. 16.2f)
exhibits a formyl group at C 3 meanwhile chlorophyll f (Fig. 16.2g) contains a formyl
group at C 2 (Chen and Blankenship 2011).
The members of the chlorophyll c family differ from other Chls in that they
are porphyrins (i.e. they have a fully unsaturated tetrapyrrole macrocycle), which
usually are non-esterified with phytol at C17
3 . Since 1990, the number of members
of the chlorophyll c family increased from seven (c 1 , c 2 , c 3 , c CS-170 , c 2 -like pigment
393
health benefits for humans, such as antioxidant, antimutagenic, antigenotoxic, and
anti-inflammatory activities (Pérez-Gálvez et al. 2017).
Consequently, the use of these molecules as an additive of colour in food is strictly
regulated in the United States, the European Union, and many other countries in
the world, such as China, India, Canada, Australia, New Zealand, Brazil, and Japan.
Currently, commercially available chlorophyll compounds consist of structures basically related to chlorophylls a and b (Rodriguez-Amaya 2019), being emerging the
exploration of no explored structures as species c, d, and f and their derivatives as
alternatives to natural green dyes. Additionally, as a colour stabilization strategy,
microalgae biomass appears to be a potential alternative as a functional ingredient
with green colouring properties as secondary effect.
Thus, the purpose of this chapter is to provide a comprehensive overview of the
application of chlorophylls and their compounds derived in foods, with emphasis
on microalgae as potential sources for obtaining these compounds. Moreover, it is
revised chemical structure of chlorophylls, distribution, biological properties of these
compounds, including regulatory milestones in force in different countries for your
application.
16.2 Structure and Distribution Chlorophylls
Natural chlorophylls are the most abundant pigments in nature, occurring more than
100 different structures, found in oxygenic photosynthetic organisms such as higher
plants, microalgae, algae, and some bacteria (Lanfer-Marquez and Borrmann 2009;
Pérez-Gálvez et al. 2017).
The structure of chlorophylls is tetrapyrrole with a system of coplanar conjugated
double bonds that forms the chromophore with delocalization of electron density in
π orbitals, formed from one magnesium atom as the central metal and a phytyl chain
(C 20 H 40 ) esterifying the propionic acid at C17 3 , gives chlorophyll a hydrophobic
character, as shown in Fig. 16.1 (Yilmaz and Gökmen 2016).
Chlorophylls a, b, and c were reported in the nineteenth century (Govindjee 2004),
chlorophyll d was identified more than 70 years after the other chlorophylls (Manning
and Strain 1943), and chlorophyll f was reported in 67 years after (Chen et al. 2010).
However, the major chlorophylls in food additives are chlorophyll a and chlorophyll
b (Viera et al. 2019).
Chlorophyll a (Fig. 16.2a, b) are different at position C 7 , where chlorophyll a
is composed of methyl group and chlorophyll b is composed of formyl group. The
chlorophylls d and f are similar to chlorophyll a, where chlorophyll d (Fig. 16.2f)
exhibits a formyl group at C 3 meanwhile chlorophyll f (Fig. 16.2g) contains a formyl
group at C 2 (Chen and Blankenship 2011).
The members of the chlorophyll c family differ from other Chls in that they
are porphyrins (i.e. they have a fully unsaturated tetrapyrrole macrocycle), which
usually are non-esterified with phytol at C17
3 . Since 1990, the number of members
of the chlorophyll c family increased from seven (c 1 , c 2 , c 3 , c CS-170 , c 2 -like pigment