Research Progress on Resource Characteristics, Functional Activity and Processing Technologies of Seed Oils from Woody Spice Plants in Guangxi

Guangxi spans from the northern tropical zone to the middle subtropical zone and is rich in natural woody plant seed resources (including spice and oil plants). Woody spice plant seeds are characterized by remarkable varietal diversity, distinct regional features and high-value active ingredients, making them an excellent raw material for the development of functional oils. However, the development of woody vegetable oil in Guangxi is restricted by problems such as lagging large-scale planting, high investment in new extraction equipment (5 to 8 times higher than that in traditional extraction processes), and insufficient coordination across the industrial chain. Moreover, existing research has problems such as lagging systematic evaluation of germplasm resources, fragmented research on active components, and insufficient industrialization of green extraction technology. This article outlines an overview of the resources (geographical distribution, yield, and oil content), active components and extraction processes (traditional pressing, traditional solvent extraction, supercritical CO₂ extraction and subcritical extraction, in terms of oil extraction rate, advantages, and disadvantages) of Guangxi’s specialty woody plant seeds such as osmanthus seed oil, camphor tree seed oil, Litsea cubeba seed oil, star anise seed oil and Camellia oleifera seed oil. On this basis, a regional resource atlas is presented and current challenges and future directions are discussed to provide an important reference for promoting innovation in Guangxi’s characteristic oil industries and ensuring the security of vegetable oil supply in China.