## 1 Introduction  
Lately, the interest in studying the food applications of microalgae has increased significantly due to high nutritional value and a vast variety of novel metabolites with numerous innovative food applications. These could be considered such as nutraceuticalids, food supplement, functional ingredients, or functional foods. Continually, new interpretations, and dynamic situation in the food sector provoke that these applications are situated between ordinary food and medical drugs [1]. In addition, huge interest has emerged among consumers and the nutrition industry in novel products that can promote good health, improve the state of wellbeing, and decrease the risk of diseases [1,2]. Diabetes, cardiovascular diseases, obesity, hypertension, cancer, or depression are some examples of diseases where these novel products combined with healthy lifestyle could modulate them [1,2]. Although microalgae have been used for centuries as a source of nutrition [3],many species such as _Arthospira maxima_, _A. platensis_, _Chlorella vulgaris_, _Haematococcus pluvialis_, _Isochrysis galbana_, _Scenedesmus_ sp., _Porphyridium cruentum_, or _Phaedactylum tricornutum_ have been recently included for their composition [4; 5; 6]. Proteins, amino acids, polysaccharides, pigments, carotenoids (\(\beta\)-carotene or astaxantina), vitamins, and fatty acids between other are compounds described for theirs beneficial health effects such as: anti-inflammatory, protection of UV radiation, immune system, arthritis, Alzheimer's disease, or cancer or applications in pharmaceutical or cosmetics industries (natural colorants or anti-aging products) [1; 4; 5; 7]. This current research particularly focused on _Isochrysis galbana_ (Phylum: Haptophyta). This marine microalga has served in the aquaculture industry as a feed of bivalves, fish larvae, crustaceans, and mollusks for years [8]. Recently, this microalga has also been of interest in adjusting the composition of significant biomolecules, such as polysaccharides, fatty acid, carotenoids, vitamin, and sterols which are bioactive compounds that elicit positive nutrition in human foods or animal feed. Further, these molecules have demonstrated their therapeutic potential against several diseases like cancer, diabetes, cardiovascular and infectious diseases, among others [9; 10]. _I. galbana_ has also been described as a significant source of vitamin A and E, folic acid, nicotinic acid, pantothenic acid, biotin, thiamin, riboflavin, pyridoxine, cobalamin, chlorophyll (a and c), fucoxanthin, and diadinoxanthin [11]. _I. galbana_ harbors specific carotenoid fucoxanthin and has high content of bioactive compounds including polyunsaturated fatty acids (PUFA) profile such as docosahexaenoicenoic acid (DHA). Fucoxanthin is also present in brown seaweed or several diatoms, such as _Phaedactylum tricornutum_, and its activity as an anti-inflammatory, antioxidant, and anticancer has been demonstrated in several studies [12]. Additionally, fucoxanthin is also able to modulate certain genes implicated in the cell metabolism, a property seemingly essential for good health [13; 14]. In addition, the presence of PUFA is beneficial because they contribute to the production of prostaglandandins, and/or thromboxanes which are biologically active substances that play important roles in the reduction of cholesterol and triglycerides in the blood as well as prevention of cardiovascular diseases, atherosclerosis, skin diseases, and arthritis [15; 16]. PUFAs should be included in the daily diet because they cannot be synthesized by humans or animals per se [16]. For the extraction of bioactive compounds, an ideal extraction method should result in a rapid quantitative recovery of the target without degradation, and the removal of the solvent post-extraction should be easy and rapid. Many bioactive natural products are thermolabile and can degrade while using traditional extraction methods.