Study on optimizing the process of steam distillation for extraction volatile oil from Alpinia oxyphylla and its antimicrobial activities in vitro

OBJECTIVE To explore the optimal extraction processing and study the antimicrobial activities of the volatile oil from Alpinia oxyphylla Miq..METHODS The volatile oil was extracted by steam distillation method.The amount of solvent,soaking time and extraction time were investigated by orthogonal testing design using the extraction rate of volatile oil as index.The antimicrobial activities and minimum inhibition concentration(MIC)of the volatile oil were tested by disk diffusion method and two-fold dilution method in vitro,respectively.RESULTS The optimal extraction condition were obtained.Antibacterial activities against the tested strains of the volatile oil were found.CONCLUSION The optimized processing was efficient and feasible,which can be used in industrial production.The volatile oil from Alpinia oxyphylla Miq.showed good antimicrobial activity against bacteria.