Anise essential oil can be obtained from the fruits by either steam distillation or extraction using supercritical carbon dioxide. The yield of essential oil is influenced by the growing conditions and extraction process, with supercritical extraction being more efficient. Regardless of the method of isolation the main component of the oil is anethole (80–90%), with minor components including 4-anisaldehyde, estragole and pseudoisoeugenyl-2-methylbutyrates, amongst others. (Alternately found by Orav et al. 2008 to be 2-6% extracted oil by weight of raw seed material, 74-94% being trans-anethole and the remaining fraction estragole (methylchavicol), anisaldehyde and γ-himachalene.) Anethole is responsible for anise’s characteristic odor and flavor.
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