# 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

## TL;DR

This study analyzes the chemical composition and bioactivity of Zhoupigan citrus essential oil using advanced analytical techniques and compares two extraction methods.

## Contribution

The study provides a comprehensive evaluation of ZJPEO using HS-GC-IMS and HS-SPME-GC-MS, identifying key VOCs and their bioactivity.

## Key findings

- SFEO showed stronger sweet, green, and woody aroma notes compared to SDEO.
- Terpenoids and esters were identified as major contributors to ZJPEO's aroma and bioactivity.
- SFE extraction produced essential oil with higher antioxidant and antimicrobial activities.

## Abstract

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.

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.

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.

Overall, this work supports optimizing ZJPEO extraction and promoting its value-added, sustainable utilization.