Chemical Composition, Antioxidant Capacity, Phenolic and Flavonoid Content and Antibacterial Activity of Coriander (Coriandrum sativum L.) Essential Oil against Bacterial Pathogens of Fish

Abstract Coriandrum sativum L. essential oil (EO) was investigated for its chemical composition and antibacterial activity against fish pathogenic bacteria, including the Gram positive strain Lactococcus garvieae (10/3) and Gram negative strain Aeromonas salmonicida (176/1 and ATCC 33658), Vibrio harveyi (160/19), Vibrio anguillarum (50/1) using Kirby-Bauer disk diffusion method. The main components of C. sativum EO were identified as Bicyclohepten (35.09%), Linalool (30.76%) and Pregnane (12.81%). The antioxidant activity of C. sativum EO was tested using DPPH scavenging assay. The radical scavenging activity, total phenolic and flavonoid content of the EO were 87.28%, 135.92 ± 0.25 mg GAE g–1, and 86.61 ± 0.45 mg QE g–1 respectively. The essential oil showed significant inhibitory activity, ranging from 20 to 42.66 mm at a concentration of 1000 µL mL–1 against V. harveyi (160/19), V. anguillarum (50/1), L. garvieae (10/3), E. coli ATCC 25922 (ref. strain) A. salmonicida (176/1) and A. salmonicida ATCC 33658 (ref. strain) (p < 0.05). These findings suggest that C. sativum EO has potential as a natural antimicrobial agent and warrants further investigation through in vivo studies in aquaculture systems.