Comparison of antioxidant and antibacterial effects of the Eucommia wood vinegar under the refining methods of atmospheric distillation and vacuum distillation

In this study, the crude wood vinegar (WVC) was prepared via pyrolysis at 650 °C using Eucommia ulmoides Oliver (EUO) wood. In order to improve the quality and comprehensive of wood vinegar (WV) by two distillation methods were systematically investigated. The experimental results showed that the WV differed in terms of physicochemical properties, antioxidant activity and antibacterial activity. The antioxidant activities of the cut fraction of atmospheric distillation (WVAD100) and vacuum distillation (WVVD90) reached up to 92.00% and 90.00% after diluted 1000 times, respectively. However, the residual liquor of atmospheric distillation (WVAD25) and vacuum distillation (WVVD25) exhibited satisfactory antibacterial performance. The gas chromatography-mass spectrometry and headspace gas chromatography-mass spectrometry analysis showed that the higher antioxidant activity of the WV was mainly related to the contents of phenols and ketones, and the antibacterial activity of the residues was related to the contents of aldehydes and esters. It provides practical and technical support to the development of antioxidant and antimicrobial for WV-based materials.