Identification of key volatiles affecting the flavour of Hainan ‘Shanyou’ (Camellia hainanica) oil by GC–MS

Shanyou oil (SYO), extracted from the seeds of Camellia hainanica in Hainan, is highly valued for its distinctive flavour, compared with that of other camellia seed oils (CSOs). To investigate the chemicals that contribute to its unique aroma, oils from 13 regions across Hainan, Guangdong, and Guangxi were collected. Sensory evaluation revealed that the SYO has intense coffee-like, caramellic, nutty, and potato-like aromas, which are significantly stronger than those of CSOs from other regions. Headspace solid-phase microextraction combined with gas chromatography–mass spectrometry (HS–SPME–GC–MS) revealed the presence of 103 volatile organic compounds (VOCs). Differential analyses of VOCs between samples revealed that acetoin and 2,3-butanediol were markedly abundant in SYO and served as key contributors to its characteristic caramel-like aroma. This study provides critical insights into the flavour chemistry of SYO, facilitating its authentication and quality evaluation. • Shanyou oil (SYO) from C . hainanica exhibits a more intense and complex aroma profile. • A total of 103 volatile organic compounds (VOCs) were identified. • SYO exhibits stronger coffee-like, caramellic, nutty and potato-like aromas. • Acetoin and 2,3-butanediol were identified as signature VOCs significantly enriched in SYO. • The unique VOC profile of SYO is attributed to the combination of the C . hainanica decaploid germplasm and Hainan's specific geographical conditions.