Abstract:

This study aimed to develop a method for β-carotene extraction from Dunaliella salina by water-soluble
organic solvents. In experiments, in reference to ethyl acetate, four water-soluble organic solvents, namely acetone,
methanol, ethanol and tetrahydrofuran, were selected as media to extract β-carotene from Dunaliella salina cultured under
laboratory conditions. β-carotene and its geometrical isomers in each extract were determined by C18-HPLC and C30-HPLC,
respectively. By comparing the extraction efficiency of β-carotene and solvent consumption and meanwhile considering
food safety, ethanol was selected as the most suitable medium for industrial practice. By using ethanol as the extraction
medium, 0.32 μg of β-carotene was extracted from 1 mg of dried Dunaliella salina with 20.21% (m/m) of total Z-isomers.
Four carbohydrates and one protease were then employed to destroy the cell wall and membrane of algae. The influences
of enzymatic hydrolysis of raw material on the extraction efficiency of β-carotene and solvent consumption were observed.
Data obtained from this investigation suggested that enzymatic hydrolysis of Dunaliella salina resulted in loss of β-carotene
amount and exhibited no improvement in solvent consumption. It is therefore not considered to be applied.

Key words: Dunaliella salina, β-carotene, water-soluble organic solvent, enzyme, geometrical isomer, HPLC