Extraction of Carotenoids and Fat-Soluble Vitamins from Tetradesmus Obliquus Microalgae: An Optimized Approach by Using Supercritical CO2

Abstract

In recent years, great attention has been focused on rapid, selective, and environmentally friendly extraction methods to recover pigments and antioxidants from microalgae. Among these, supercritical fluid extraction (SFE) represents one of the most important alternatives to traditional extraction methods carried out with the use of organic solvents. In this study, the influence of parameters such as pressure, temperature, and the addition of a polar co-solvent in the SFE yields of carotenoids and fat-soluble vitamins from T. obliquus biomass were evaluated. The highest extraction of alpha-tocopherol, gamma-tocopherol, and retinol was achieved at a pressure of 30 MPa and a temperature of 40 °C. It was observed that overall, the extraction yield increased considerably when a preliminary step of sample pre-treatment, based on a matrix solid phase dispersion, was applied using diatomaceous earth as a dispersing agent. The use of ethanol as a co-solvent, under certain conditions of pressure and temperature, resulted in selectively increasing the yields of only some compounds. In particular, a remarkable selectivity was observed if the extraction was carried out in the presence of ethanol at 10 MPa and 40 °C: under these conditions, it was possible to isolate menaquinone-7, a homologous of vitamin K2, which, otherwise, cannot not recovered by using traditional extraction procedures.

Long-chain vitamin K2 production in Lactococcus lactis is influenced by temperature, carbon source, aeration and mode of energy metabolism

“…As hydrophobic, membrane-embedded compounds, menaquinones are not produced extracellularly and continuously, but remain cell-associated in all producing bacteria. Nevertheless, simple and efficient procedures are being continuously developed and optimized for extracting vitamin K2 and other valuable cell-associated molecules from biomass [37–39], that, together with the knowledge obtained from this study, will facilitate the biotechnological production of long-chain vitamin K2.…”

Isolation of Industrial Important Bioactive Compounds from Microalgae

“…All of these, suggest microalgae enriched food as a good source of nutritional supplements especially for strict vegetarians owing to its rich high-value nutrients as well as Vitamin B 12 . Chronopoulou et al [ 102 ] proposed an improved approach to extract fat-soluble vitamins by using supercritical CO 2 while a previous study compared six extraction methods for Vitamin B 12 from Spirulina and found the aqueous extraction suits best for this studied compound [ 103 ].…”

Medicinal Prospects of Antioxidants From Algal Sources in Cancer Therapy

“…are another reservoir of provitamin A (Kay and Barton, 1991). Chronopoulou et al, has reported that extraction of vit A from Tetradesmus Obliquus is in the highest amount through supercritical fluid extraction method (Chronopoulou et al, 2019). Higher intake of dietary Vit A can remarkably decrease the ovarian, lung, gastric, pancreatic, and cervical carcinoma risk (Sanusi, 2019;Wang and He, 2020).…”