Optimization of ultrasonic-assisted salting-out assisted extraction of essential oil from Piper nigrum L.and its activity analysis
The ultrasonic-assisted salting-out assisted steam distillation method was used to extract essential oil from Piper nigrum L..Response surface methodology was used to determine the optimal extraction parameters such as liquid-solid ratio,ultrasonic time and NaCl concentration.The results showed that the optimal extraction condition of essential oil from Piper nigrum L.by ultrasonic-assist-ed distillation method was the liquid-solid ratio of 17∶1,ultrasonic time of 13 min,and NaCl concentration of 2.4%.Under this condi-tion,the extraction yield of Piper nigrum L.essential oil was 1.79%.The extracts obtained by this method were tested for antioxidant and antibacterial activities.The results showed that Piper nigrum L.essential oil had a certain antioxidant capacity,and its scavenging ability on ABTS was much stronger than that on DPPH.The extract also showed strong growth inhibition against both Staphylococcus aureus and Pseudomonas solanacearum.