Characterization of Seven Species of Oil: Oil Content, Volatile Compounds, and Oxidative Stability.

In this study, we conducted tests on the seeds from four Taiwanese native species (, , , and ) and three commercialized species (, , and ) for comparison. We examined various aspects of these species, such as seed oil content, suitability for mechanical pressing, volatile components (edible flavor), and oil stability (suitability for cooking), to assess the feasibility of using these four native Taiwanese seeds as sources of edible oil. The results from solvent extraction tests and mechanical pressing experiments confirm that the seeds from , , and have high oil contents, and their oils are suitable for extraction via the popular mechanical pressing method, with oil yields comparable to or higher than those of the commercialized species. The volatile components of the oils were collected using MonoTrap adsorbents and analyzed with a thermal desorption system coupled with gas chromatography-mass spectrometry (ATD-GC/MS), primarily consisting of alcohols, ketones, and aldehydes. The results of oxidative stability tests reveal that the seed oils from , , and are higher than or equally stable to those from the commercialized species. After six months of storage, the stability of these three seed oils remained relatively high, demonstrating that the seed oils from , , and can withstand high temperatures and can be easily preserved for future applications.