Master of Science (MS)


Renewable Natural Resources

Document Type



Supercritical fluid extraction (SFE) of oxeye daisy (Chrysanthemum leucanthemum L.) seed, heartwood of Port-Orford cedar (POC) (Chamaecyparis lawsoniana), Alaska yellow cedar (AYC) (Chamaecyparis nootkatensis), and Eastern red cedar (ERC) (Juniperus virginiana L), and Chinese tallow (Sapium sebiferum L. Roxb. ) seed was investigated in this study and compared with other extraction methods. For the oxeye daisy seed extraction, Soxhlet extraction (SE) with hexane, microwave assisted extraction (MAE), and supercritical fluid extraction (SFE) were conducted. The results showed that as the extraction temperature decreased from 100 °C, the extraction rate increased until 30 °C using SFE. With an increase of extraction pressure from 100 bar to 300 bar, the extraction rate increased using SFE. Most ultraviolet waves did not pass through the oxeye daisy oils at a wavelength range 200 nm to 300 nm when the oil concentration was 0.4% (v/v). The MAE oil and SFE showed stronger DPPH radical-scavenging ability than SE oil at the same concentration. For the three cedars extraction, samples were supercritical fluid extracted with CO2 and Soxhlet extracted with hexane. The extracted oils were evaluated against two common wood decay fungi, brown-rot fungi (Gloeophyllum trabeum) and white-rot fungi (Trametes versicolor). The result showed that the SFE yield of ERC, AYC, and POC was 3.27%, 3.22%, and 3.29%, respectively. The SE yield of ERC, AYC, and POC was 0.80%, 0.71%, and 1.52%, respectively. The statistical analysis showed that SFE cedar oils had higher antifungal activities than SE cedar oils against both fungi. In vitro studies showed that AYC oil had the strongest antifungal activity, followed by POC oil and ERC oil. For the Chinese tallow seed extraction, SFE and SE were conducted. 5% or 10% methanol (MeOH) was added to the supercritical CO2 as a modifier. The results showed that the collecting time could significantly affect the extraction yield. The extraction yield with 10% MeOH (32.61%) is higher than with 5% MeOH (30.85%) or without MeOH (30.75%). More components could be extracted when using a modifier based on GC-MS analysis. In sum, supercritical fluid extraction showed several advantages in the extraction of plant oils over Soxhlet extraction.



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Committee Chair

Shupe, Todd Finley