17 Carotenoids as Food Additives
429
‘exempt from certification’ category. It is widely used as a drug, food and cosmetic
colourant (e.g. for skin tanning), and it gives peach to reddish-orange colour to these
products [e.g. dairy products (cheese), confectionary (soft and hard candy), fish and
meat products, fruit products, beverages, snacks, beer and wine] (Aberoumand 2011;
Tanka et al. 2012; Code of Federal Regulations 2019). It is rather used in water-based
(than in fat-based) foods in confectionary (e.g. hard candies, fruit jellies, marzipan,
sugar-coated tablets, ice cream, wafer biscuits), bakery products, fruit juices, tomato
juices, soups, canned products (like frankfurter sausages, cod roe, prawns, shrimps—
where by adjusting the conditions suitably, the carotenoid will adhere to the surface),
primarily because of the duplication of colour shade. As a lipophilic compound,
canthaxanthin accumulates in food, mostly in fatty tissues, i.e. broiler skin, egg yolks
and fish fillets, and in the cuticles of crustaceans (Amaya et al. 2014). By using an
appropriate grade of chlorophyll with canthaxanthin, very attractive shades of brown
can be achieved for hard candies and marzipan (NIIR Board 2017). It is also widely
used in poultry (e.g. broiler, laying hens) as a feed additive to improve the colour
shade of yolk and for colouring the skin (Santos-Bocanegra et al. 2004; EFSA 2010;
Esatbeyoglu and Rimbach 2017). As canthaxanthin has a high commercial value, its
biosynthesis has also been studied extensively. It is biosynthesized from β-carotene
with the help of β-carotene ketolase, which adds carbonyl groups to the carbon atoms
at the 4 and 4’ positions in the β-carotene molecule (Torregrosa-Crespo et al. 2018).
Canthaxanthin is more stable (less susceptible to photodegradation) than carotene
(Aberoumand 2011). Pectin jellies coloured with β-carotene and canthaxanthin as
well as other natural colours showed excellent stability over six months stored in
daylight and darkness (NIIR Board 2017). During the oxidation and degradation of
carotenoids, the colour intensity decreases or can be lost; therefore, their stabilization
(e.g. with antioxidants) may be necessary (Esatbeyoglu and Rimbach 2017).
Large quantities of canthaxanthin have been applied for rats without any undesirable symptoms: a tolerance test was carried out in three consecutive generations, and
in a separate study, excessively high doses have been used for almost two years (in
the highest dose group each animal consumed a total of about 3 kg of canthaxanthin
per kg of body weight, enough for the pigmentation of 1500 ton of chicken feed). The
weight development of the animals treated with the highest doses did not differ from
the controls, and extensive haematological and histopathological examinations also
failed to reveal any evidence of toxicity (Isler et al. 1967). The JECFA (Joint Expert
FAO/WHO Committee on Food Additives) and SCF (Scientific Committee on Food)
have defined an ADI (Acceptable Daily Intake) for canthaxanthin of 0.03 mg/kg bw
that was derived from the NOAEL (No Adverse Effect Level) (European Commission
2002; EFSA 2010). The oral LD50 of canthaxanthin in mice is 10,000 mg/kg bw. In
addition to its low acute oral toxicity, canthaxanthin is not genotoxic (EFSA 2010).
Consequently, dietary canthaxanthin is considered to be safe for humans (FDA 2019;
EFSA 2010), but higher doses may lead to macular crystal formation and retinopathy
(Esatbeyoglu and Rimbach 2017).
429
‘exempt from certification’ category. It is widely used as a drug, food and cosmetic
colourant (e.g. for skin tanning), and it gives peach to reddish-orange colour to these
products [e.g. dairy products (cheese), confectionary (soft and hard candy), fish and
meat products, fruit products, beverages, snacks, beer and wine] (Aberoumand 2011;
Tanka et al. 2012; Code of Federal Regulations 2019). It is rather used in water-based
(than in fat-based) foods in confectionary (e.g. hard candies, fruit jellies, marzipan,
sugar-coated tablets, ice cream, wafer biscuits), bakery products, fruit juices, tomato
juices, soups, canned products (like frankfurter sausages, cod roe, prawns, shrimps—
where by adjusting the conditions suitably, the carotenoid will adhere to the surface),
primarily because of the duplication of colour shade. As a lipophilic compound,
canthaxanthin accumulates in food, mostly in fatty tissues, i.e. broiler skin, egg yolks
and fish fillets, and in the cuticles of crustaceans (Amaya et al. 2014). By using an
appropriate grade of chlorophyll with canthaxanthin, very attractive shades of brown
can be achieved for hard candies and marzipan (NIIR Board 2017). It is also widely
used in poultry (e.g. broiler, laying hens) as a feed additive to improve the colour
shade of yolk and for colouring the skin (Santos-Bocanegra et al. 2004; EFSA 2010;
Esatbeyoglu and Rimbach 2017). As canthaxanthin has a high commercial value, its
biosynthesis has also been studied extensively. It is biosynthesized from β-carotene
with the help of β-carotene ketolase, which adds carbonyl groups to the carbon atoms
at the 4 and 4’ positions in the β-carotene molecule (Torregrosa-Crespo et al. 2018).
Canthaxanthin is more stable (less susceptible to photodegradation) than carotene
(Aberoumand 2011). Pectin jellies coloured with β-carotene and canthaxanthin as
well as other natural colours showed excellent stability over six months stored in
daylight and darkness (NIIR Board 2017). During the oxidation and degradation of
carotenoids, the colour intensity decreases or can be lost; therefore, their stabilization
(e.g. with antioxidants) may be necessary (Esatbeyoglu and Rimbach 2017).
Large quantities of canthaxanthin have been applied for rats without any undesirable symptoms: a tolerance test was carried out in three consecutive generations, and
in a separate study, excessively high doses have been used for almost two years (in
the highest dose group each animal consumed a total of about 3 kg of canthaxanthin
per kg of body weight, enough for the pigmentation of 1500 ton of chicken feed). The
weight development of the animals treated with the highest doses did not differ from
the controls, and extensive haematological and histopathological examinations also
failed to reveal any evidence of toxicity (Isler et al. 1967). The JECFA (Joint Expert
FAO/WHO Committee on Food Additives) and SCF (Scientific Committee on Food)
have defined an ADI (Acceptable Daily Intake) for canthaxanthin of 0.03 mg/kg bw
that was derived from the NOAEL (No Adverse Effect Level) (European Commission
2002; EFSA 2010). The oral LD50 of canthaxanthin in mice is 10,000 mg/kg bw. In
addition to its low acute oral toxicity, canthaxanthin is not genotoxic (EFSA 2010).
Consequently, dietary canthaxanthin is considered to be safe for humans (FDA 2019;
EFSA 2010), but higher doses may lead to macular crystal formation and retinopathy
(Esatbeyoglu and Rimbach 2017).