Chemical composition and biological activities of essential oil isolated by HS-SPME and UAHD from fruits of bergamot

Bergamot essential oil (BEO), which is extracted from bergamot fruit peel, has many health benefits such as improving blood circulation and anticancer activity. In this paper, volatile components were obtained by headspace solid phase microextraction (HS-SPME) and ultrasound-assisted hydrodistillation (UAHD) from the fruits of bergamot (Citrus medica L. var. sarcodactylis (Noot.) Swingle). The oil yield of BEO from UAHD extraction was 0.48%, which is 118% higher than that of hydrodistillation (HD). The chemical compositions of the volatile components were analyzed using GC-MS. A total of 46 volatile compounds belonging to distinct chemical families were identified. The major components were identified as D-limonene (60.44%), γ-terpinene (20.28%). The biological activities, including antimicrobial activities and antioxidant activities of BEO were detected. The BEO exhibited activities against bacteria and fungi with minimal inhibitory concentration (MIC) values in the range of 0.78–3.13 μL/mL and minimum bactericidal or fungicidal concentration (MBC/MFC) values in the range of 1.56–6.25 μL/mL. BEO showed strong activity against E. coli (MIC = 0.78 μL/mL, MBC = 1.56 μL/mL). BEO also showed substantial antioxidant activity based on ferric reducing antioxidant power (FRAP) assay for reducing power, 2,2′-azino-bis(3-ethyl benzothiazoline-6-sulfonic acid) (ABTS) assay for radical scavenging activity, and superoxide anion radical scavenging activity.