Application of Supercritical CO2 Extraction Technology in the Extraction of β-Carotene
Supercritical CO2 extraction technology is the most common supercritical fluid extraction technology. It uses the excellent solubility of CO2 under specific conditions to separate and extract substances. It has been widely used in the extraction and separation of traditional Chinese medicine because of its cheap, easy to obtain, safe and non-toxic characteristics.
Dunaliella Salina is a kind of salt-tolerant single-cell microalgae, which has the characteristics of rapid propagation, strong viability and suitable for cultivation. Dunaliella salina contains a large number of glycerol, carotene, protein, polysaccharide compounds and trace elements, and is a kind of algae with high economic value. Extraction of beta-carotene from Dunaliella salina is a good way for human beings to obtain beta-carotene from natural animals and plants. Beta-carotene is a food additive permitted by the state. It has the functions of coloration and nutrition. It also has the functions of anti-oxidation, combination of reactive oxygen species, cracking free radicals, enhancing immunity, anti-mutation and anti-cancer. As the raw material of functional food and medical products, energy and medical function have already attracted worldwide attention and attention. The advanced supercritical carbon dioxide extraction technology was applied to extract beta-carotene from salina algae in the laboratory. The optimum technological conditions for extracting beta-carotene from salina algae by supercritical carbon dioxide extraction technology were discussed. The extraction rate of beta-carotene was 95.09% at 30 MPa, 45℃, 10 L/H of CO2 flow rate and 6 H of extraction time. Compared with conventional solvent method, it has the advantages of high extraction efficiency, fast speed, simple process, no solvent residue and pure color and taste. The results show that supercritical CO2 extraction of beta-carotene from Dunaliella salina has the value of industrial development. It was found that the supercritical CO2 extraction conditions had significant effects on the composition of the isomers of beta-carotene in Dunaliella salina. The content of cis-beta-carotene in the extract of supercritical CO_2 was 82.0%, which was much higher than that of cis-beta-carotene extracted by solvent (48.8%).
Dunaliella salina powder and natural carotene products extracted from it are new products of marine organisms, and their production technology is an integral part of marine biotechnology. There are many methods to extract beta-carotene from Dunaliella salina, such as organic solvent extraction, precipitator enrichment, supercritical carbon dioxide extraction and so on. The extraction of beta-carotene is based on organic solvents, while most organic solvents contaminate the product and the separation process is complex. Natural extracted carotene is easy to be absorbed by human body, and has good antioxidant capacity, thus forming a high demand boom.