**Author details**

Additionally, the carotenoids biosynthesized by different organisms are derived through a series of chemical and enzymatic modifications from the phytoene, such as reactions of desaturations, cyclizations, hydroxylations, glycosylation, oxidization, dehydrogenation, migration of double bonds, rearrangement, and epoxidations, as exemplified above [45]. These modifications are catalyzed by a number of enzymes which fall into few classes based on the type of transformation they catalyze such as geranylgeranyl pyrophosphate synthase, phytoene synthase, carotene desaturase, and lycopene cyclase. Modification of carotenes is further catalyzed by β-carotene ketolase and β-carotene hydrolase to generate various C40 carotenoids. Thus, all of these modifications contribute to yield a family of more than 1178

Of the total number of naturally occurring carotenoids, only eight are produced synthetically at industrial level. Between them C40 carotenoids: lycopene, β, β-carotene, (3R,3′R) zeaxanthin, canthaxanthin, and astaxanthin; and three apocarotenoids: ß-apo-8′-carotenal, ethyl ß-apo-8′-carotenoate, and citranaxanthin [47]. For the chemical synthesis, several building concepts are possible. However, on industrial scale, only few of them have been applied successfully. The reactions of Grignard elaborated by Hoffman-La Roche in 1954 and reactions of Wittig developed by Badische Anilin- & Soda-Fabrik (BASF) in 1960, were the main reactions of syntheses employed on an industrial scale; however, Wittig reaction dominates

All chemically synthesized C40 carotenoids have symmetric structures, and this is explained by the fact that all structures have identical end groups at their ends. Due to these characteristics, they are efficiently produced by double Wittig condensation of a symmetrical C10-dialdehyde as the central C10-building block with two equivalents of an appropriate C15-phosphonium salt. In addition to these synthetic steps, these mixtures of isomers are thermally isomerized, in heptane or ethanol, for the full formation of all-trans/E configurations, since during the process, certain amounts of cis/Z stereoisomers are formed [24, 48]. Additionally, to use Grignard compounds, it is necessary to combine one diketone molecule and two methanol molecules,

Other methods of the synthesis of carotenoids include the hydroxylation of canthaxanthin, a C10 + C20 + C10 synthesis via dienolether condensation, and the isomerization of a lutein

Apart from β, β-carotene, the other synthetically produced carotenoids are manufactured

Furthermore, to synthetically traded carotenoids, a portion of these pigments are obtained from natural sources such as lutein (marigold flowers), β-carotene (*Dunaliella salina*), astaxanthin (*Haematococcus* spp.), and Capsorubin (*Capsicum annuum*) (see **Table** 1) [1, 50]. β-carotene followed by lutein and astaxanthin lead the carotenoid market, which is projected to reach

In more recent times, the major commercial use of carotenoids has been as food and feed additives for coloration. They have also found some use in cosmetics and pharmaceutical products, but the most rapidly growing market now is health supplements, which in turn,

thereafter compound containing 40 carbon atoms is obtained [49].

mostly by the companies Hoffmann-La Roche and BASF [47].

extracted from marigold to zeaxanthin and then oxidation to astaxanthin [48].

compounds widely distributed in nature [4, 46].

the market currently [24, 48].

10 Progress in Carotenoid Research

USD 1.53 Billion until 2021 [51].

provides a stimulus growing from production [1].

Andrêssa Silva Fernandes<sup>1</sup> , Tatiele Casagrande do Nascimento1 , Eduardo Jacob-Lopes1 , Veridiana Vera De Rosso2 and Leila Queiroz Zepka1 \*

\*Address all correspondence to: zepkaleila@yahoo.com.br

1 Food Science and Technology Department, Federal University of Santa Maria, UFSM, Santa Maria, RS, Brazil

2 Department of Biosciences, Federal University of São Paulo, UNIFESP, Santos, SP, Brazil
