Influence of hydrodistillation parameters using NaCl solution on the yield, chemical composition, and biological activities of ginger essential oil

Abstract This study systematically investigated the influence of distillation parameters on the yield, chemical composition, and biological activities of essential oil extracted from Vietnamese ginger. Specifically, the novel use of hydrodistillation using NaCl solution was explored. The optimal conditions, determined sequentially, were: a NaCl solution concentration of 5%, a ginger powder-to-solution ratio of 1:20 (w/v), an extraction temperature of 150 °C, and an extraction time of 4 h. These collective conditions resulted in the highest essential oil yield of 0.46 ± 0.04%. GC-MS analysis identified 54 volatile compounds, accounting for 94.79% of the oil, with major constituents including α-pinene, zingiberene, and β-bisabolene. The essential oil demonstrated moderate antioxidant capacity with an IC 50 value of 51.59 ± 0.83 mg L −1 . More significantly, it exhibited potent antibacterial efficacy, showing the strongest inhibition against Gram-positive Staphylococcus aureus NRRL B-313, with a low minimum inhibitory concentration MIC of 1.25 μg mL −1 . This MIC value was markedly lower than those required for Gram-negative strains (up to 10 μg mL −1 ). These findings confirm the potential of NaCl-assisted hydrodistillation as an efficient method for obtaining ginger essential oil with promising functional properties.