Abstract: This research aimed to study the antibacterial mechanism of (-)-β-pinene on Salmonella for the purpose of providing a theoretical basis for the potential application of (-)-β-pinene as a natural food preservative. The minimum inhibitory concentration (MIC) was determined using the broth dilution method. The morphology and structure of Salmonella cells exposed to (-)-β-pinene were characterized by scanning electron microscope (SEM) and conductivity measurement. The activity of two key enzymes succinic acid dehydrogenase (SDH) and α-ketoglutarate dehydrogenase (α-KGDH) were measured to analyze the influence of (-)-β-pinene on the tricarboxylic acid cycle. Also, the effect of the change in ATP content on energy metabolism in Salmonella was investigated. The results showed that (-)-β-pinene had an MIC of 20 mL/L for Salmonella, and damaged cell morphology and structure, thus leading to increased conductivity of the bacterial suspension, as well as increased SDH and α-KGDH activity and decreased ATP level in the bacterial cells.

Key words: (-)-β-pinene, Salmonella, cellular morphology, key enzymes in tricarboxylic acid cycle, adenosine triphosphate