Table 9.
A comparison of the common extraction methods used for obtaining star anise extracts.
| Extraction Methods | Optimal Extraction Conditions | Extraction Rates (Retain Two Significant Digits) |
Advantages | Disadvantages | References |
|---|---|---|---|---|---|
| Steam distillation (SD) | fruit size: 425 μm granulometry < 0.425 mm 8% mass 1 h water volume of 200 mL |
10% | Simple equipment, convenient operation and low cost | Time-consuming and low oil yield | [99] |
| Ultrasonic-assisted extraction (UE) | solid-to-liquid ratio of 1:15 (g/mL) crushing particle size of 60 mesh ultrasonic time of 30 min |
28% | Stable temperature, simple operation, short extraction time | Difficult and costly equipment manufacture | [100] |
| Supercritical fluid CO2 extraction (SCFE) | 1 h extraction temperature 40 °C extraction pressure 250 bar |
15% | Low temperature extraction No solvent residue |
Strict requirements for equipment and materials | [9] |
| Microwave-assisted Soxhlet extraction (MAEE) | ratio of solvent to sample 17 mL/g extraction time 16 min microwave power 505 W |
25% | Safe and environmentally friendly High extraction rate Short time |
High operational requirements | [35,98,99] |