Table 3.
Date seed oil recovery based on extraction methods.
| Method | Conditions of Extraction | Conclusions | References |
|---|---|---|---|
| Soxhlet | Extraction yield 5% (chloroform, hexane), 4 h Extraction yield 1% (propanol, methanol), 4 h |
The yield is better with non-polar solvents (n-hexane, chloroform) compared to polar solvents (methanol and propanol) | Ali et al. (2015) [70] |
| Soxhlet | Extraction yield 4.44%, hexane, 8 h | The ultrasound- and microwave-assisted extractions reduced the extraction time compared to Soxhlet and of extraction yield compared to maceration | Ben-Youssef et al. (2017) [71] |
| Ultrasound | Extraction yield 6.18%, hexane, 15 g, 20 °C, 30 min | ||
| Microwave | Extraction yield 4.74%, methyltetrahydrofuran (MeTHF), 15 g, 30 min | ||
| Maceration | Extraction yield 4.04%, MeTHF, 15 g, RT, 30 min | ||
| Soxhlet | Extraction yield 8.5%, hexane, 50 g, 78 °C, 3 h | The extraction by ultrasound shortened extraction time when compared to Soxhlet, reduced energy consumption, and had higher yield. | Jadhav et al. (2016) [72] |
| Maceration | Extraction yield 4.2%, hexane, 50 g, RT, 3 days | ||
| Ultrasound | Extraction yield 8.5% hexane, 50 g, 20 °C, 45 min | ||
| SC-CO2 | Extraction yield 3%, 5 g, 40 min, 70 °C | In this case, the oil yield was very low, probably due to several compatibilities of CO2 with the oil. | Aris et al. (2013) [73] |
| Soxhlet | Oil yield 8.5%, 120 min, hexane | The oil composition indicated the presence of low molecular weight saturated fatty acids. | Ali et al. (2015) [70] |
| Soxhlet | Oil yield 9.78, 8, and 9.5%, methanol, ethanol and acetone, respectively | The best conditions were found using methanol 15 °C above its boiling point, particle size range of 0.212–1 mm, 4 h. | Al-Sumri et al. (2016) [74] |
| SC-CO2 | Oil yield 14%, 250 bar, 333 K | The pressure and the interaction between the pressure and temperature had a positive significant effect on the extraction yield | Mehdi et al. (2019) [75] |