Star anise oil
Oil of star anise is a colorless or pale yellow, clear liquid with an odor similar to star anise. It often becomes cloudy or crystallizes when cold, but becomes clear upon warming.
Star anise oil is readily soluble in 90% ethanol.
Sensory Properties
Color: Colorless to light yellow
State: Clear liquid or solid
Aroma: Characteristic aroma of anethole
Physical and Chemical Properties
Relative Density: 0.975-0.992 (20°C/20°C)
Refractive Index: 1.5525-1.5600 (20°C)
Optical Rotation: -2° to +2° (20°C)
Freezing Point: ≥15.0°C
The aromatic oil extracted from the steamed branches, leaves, and berries of the star anise tree is commonly known as anise oil or star anise oil. The typical oil content is 0.75% to 0.95% in fresh leaves, 1.7% to 2.7% in seeds, and 5% to 6% in the peel.
The main component is anethole (molecular formula: C₁₀H₁₂O), along with anisyl ketone, anisaldehyde, α-pinene, limonene, linalool, and borneol. Anethole is a colorless to pale yellow liquid that solidifies at low temperatures to form white crystals. Its relative density is 0.980 to 0.994.
The star anise oil contains 85% to 95% anisole, which can be oxidized to produce anisaldehyde and anisyl alcohol. It has a spicy and fragrant flavor and is used as a premium flavoring in cosmetics, food, and beverages. It is also the primary raw material for synthesizing the female hormone hexaneestrol in the pharmaceutical industry.
