Unraveling the volatile profile and bioactivity of Zhoupigan (Citrus reticulata cv. Manau Gan) essential oil via HS-GC-IMS and HS-SPME-GC-MS: a comprehensive evaluation of different extraction techniques

Introduction Zhoupigan ( Citrus reticulata cv. Manau Gan), also known as Zangju or Shitougan, is a distinctive Chinese citrus resource valued for both traditional medicinal uses and food flavoring, and is notably rich in essential oils (EOs). However, the chemical composition and bioactivity of Zhoupigan peel essential oil (ZJPEO) remain insufficiently understood, limiting its effective utilization. Methods In this study, ZJPEO was extracted by steam distillation (SD) and supercritical fluid extraction (SFE) and analyzed using FTIR, E-nose, HS-GC-IMS and HS-SPME-GC-MS. And its antioxidant and antimicrobial activities were evaluated in vitro . Results FTIR and E-nose revealed clear compositional differences between steam-distilled essential oil (SDEO) and supercritical fluid-extracted essential oil (SFEO). HS-GC-IMS detected 63 VOCs and, based on VIP > 1, identified five marker compounds. HS-SPME-GC-MS identified 1,250 VOCs, showing terpenoids and esters as major contributors to aroma and bioactivity. KEGG enrichment highlighted sesquiterpene and triterpene biosynthesis as key pathways. Flavor wheel analysis indicated that SFEO had stronger sweet, green, and woody notes and exhibited potent antioxidant and antimicrobial activities associated with specific VOCs. Discussion Overall, this work supports optimizing ZJPEO extraction and promoting its value-added, sustainable utilization.