**1. Introduction**

Fucoxanthin is an orange-colored pigment, which accounted for more than 10% of the estimated total carotenoids production in the nature [1]. It is the most abundant and signature carotenoid in brown macroalgae and diatoms [2]. It is a part of fucoxanthin– chlorophyll *a* protein (FCP) complexes along with proteins and chlorophyll *a* (chl *a*) that are functionally associated with the light-harvesting complex of the algae [3].

It has been shown that fucoxanthin possesses numerous biological activities and health-stimulating properties such as anti-angiogenic, anti-diabetic, antioxidant, antiinflammatory, and antimalarial activity [4,5]. Notably, in vivo studies (mice and human) have proven that fucoxanthin effectively decreases body weight [6,7]. In addition, fucoxanthin has been demonstrated to exhibit a wide range of anticancer and anti-proliferative activity in different in vivo and in vitro studies [8]. These bioactivities of fucoxanthin are attributed to its unique molecular structure such as an allenic bond, an acetyl group, and a

**Citation:** Khaw, Y.S.; Yusoff, F.M.; Tan, H.T.; Noor Mazli, N.A.I.; Nazarudin, M.F.; Shaharuddin, N.A.; Omar, A.R. The Critical Studies of Fucoxanthin Research Trends from 1928 to June 2021: A Bibliometric Review. *Mar. Drugs* **2021**, *19*, 606. https://doi.org/10.3390/md19110606

Academic Editors: Masashi Hosokawa and Hayato Maeda

Received: 24 September 2021 Accepted: 12 October 2021 Published: 26 October 2021

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conjugated carbonyl with a 5,6-monoepoxide [9]. Due to its multiple health benefits, the global total fucoxanthin market is estimated to increase from \$88 million in 2019 to more than \$100 million over the next five years (Global Fucoxanthin Market 2020).

Bibliometric analysis is an approach that analyzes the worldwide scientific production and qualitative data. The analysis could provide information on the research trends and future directions within a specific research field [10]. Lately, a bibliometric analysis of microalgae research, microalgae-based wastewater treatment, global dinoflagellate research, and microalgae-derived pigments has been performed [10–13]. These bibliometric analyses focused on microalgae or metabolites generated from microalgae. Silva et al. (2020) [12] only reviewed four pigments, chlorophylls, phycocyanin, and β-carotene of the microalgae using a bibliometric approach. A critical examination of the research trends of fucoxanthin utilizing the bibliometric method is still lacking. Thus, this review aimed to analyze the research trends of the fucoxanthin field via bibliometric analysis. Several conclusions can be drawn through the analysis, such as evaluating essential milestones over the history of a scientific field and the scientific fads. The keyword analysis in the current review highlighted the trends and directions of fucoxanthin research. The review could serve as a basis in fortifying the future direction of fucoxanthin research.
