###### Abstract  
In the last 20 years, xanthophylls from microalgae have gained increased scientific and industrial interests. This review highlights the essential issues that concern this class of high value compounds. Firstly, their chemical diversity as the producer microorganisms was detailed. Then, the use of conventional and innovative extraction techniques was discussed. Upgraded knowledge on the biosynthetic pathway of the main xanthophylls produced by photosynthetic microorganisms was reviewed in depth, providing new insightful ideas, clarifying the function of these active biomolecules. In addition, the recent advances in encapsulation techniques of astaxanthin and fucoxanthin, such as spray and freeze drying, gelation, emulsification and coacervation were updated. Providing information about these topics and their applications and advances could be a help to students and young researchers who are interested in chemical and metabolic engineering, chemistry and natural products communities to approach the complex thematic of xanthophylls. xanthophylls; microalgae; biosynthesis; processes; extraction; encapsulation 2020 October 2021 10 November  
of biomass, and generating global revenue of about 5.8 billion USD [11]. Among the large diversity of high-value added compounds from microalgae, carotenoids are one of the most pertinent groups to be valorized. The anti-oxidants \(\alpha\)-carotene, \(\beta\)-carotene, lycopene, astaxanthin (ASX), lutein and canthaxanthin are the main high value carotenoids from microalgae. Chemically, carotenoids have a general C40 backbone structure composed of isoprene units (terpenoid), characterized by a color that turns from yellow to red [12]. These pigments are classified into carotenes (do not containing O\({}_{2}\)) and xanthophylls (containing O\({}_{2}\)) [13]. Xanthophylls have received a lot of attention because of their diverse biological functions in all living organisms [14; 15]. Their most interesting biological roles are associated with their antioxidant properties, depending on their molecular structure [16]. Xanthophylls play the role of potent scavengers of reactive oxygen (ROS) and reactive nitrogen (RNS) species and effective chain-breaking antioxidants [17]. The addition of xanthophylls in foods is very beneficial as they are able to protect cells against oxidative damage [18]. They are also of interest because they protect the quality of food products during processing and storage. Among marine xanthophylls, the most interesting and abundant is fucoxanthin (C\({}_{42}\)H\({}_{58}\)O\({}_{6}\)), accounting for about 10% of total carotenoid production [19]. High concentrations of this xanthophyll are found in the chloroplasts of several brown algae, giving them an olive-green or brown color, and in diatoms (_Bacillus Haplynta_) [20; 21]. The second xanthophyll of interest is ASX (C\({}_{40}\)H\({}_{52}\)O\({}_{4}\)), which is a red-pink carotenoid. It is known as a powerful antioxidant since it has about ten times more antioxidant activity than other carotenoids [11]. The principal natural source of this xanthophyll is the microalgae _Haematococcus pluvialis_, which is already produced on an industrial scale [20]. Lutein and zeaxanthin (C\({}_{40}\)H\({}_{56}\)O\({}_{2}\)), two isomers, are yellow pigments found in several microalgae species such as _Chlorella minutissima_ and _Nannochloropsis oculata_. The cyanobacteria, _Spirulina platensis_ pacifica is also a relevant source of the red \(\beta\)-cryptoxanthin (C\({}_{40}\)H\({}_{56}\)O) and zeaxanthin. Today, the most available pigments on the market are fucoxanthin and ASX, followed by lutein (C\({}_{40}\)H\({}_{52}\)O\({}_{2}\)), a yellow isomer of zeaxanthin and canthaxanthin (C\({}_{40}\)H\({}_{52}\)O\({}_{2}\)) from green algae [5; 22]. Up to now, most commercial xanthophylls have been produced artificially [16]. However, interest in natural foods has increased the demand for natural sources of xanthophylls [23].