柚皮精油提取工艺及抗氧化抑菌活性研究

Study on Extraction Process and Antioxidant,Antibacterial Activity of Essential Oil from Pomelo Peel

为提高柚皮的附加值,采用微波超声协同方法提取柚皮精油,以柚皮精油得率为考察指标,在单因素试验的基础上运用响应面法优化提取工艺。结果表明,柚皮精油微波超声+溶剂提取最佳工艺为微波功率450 W、微波时间8 min、超声功率400 W、超声时间15 min、石油醚与柚皮的比例为6∶1(mL/g)、萃取温度36.8℃,在此工艺下提取的精油得率为(8.0±0.33)%。当精油浓度为10%时,羟自由基清除率为98.29%;低于同浓度的VC,DPPH自由基清除率为49.28%,远低于同浓度的VC,但上升趋势明显;精油对金黄色葡萄球菌、大肠杆菌具有明显的抑制效果。总之,柚皮精油具有优异的抗氧化和抑菌活性,可进一步开发成天然保鲜剂应用于食品加工与贮藏。

In order to improve the utilization value of pomelo peel,essential oil was extracted from pomelo peel by microwave-ultrasonic synergistic method.With the yield as the index,the optimal scheme was determined by response surface methodology on the basis of single factor experiment.The optimal process conditions were that microwave power was 450 W,microwave time was 8 min,ultrasonic power was 400 W,ultrasonic time was 15 min,the ratio of petroleum ether to pomelo peel was 6∶1(mL/g),and extraction temperature was 36.8℃.Under this condition,the yield of essential oil was(8.0±0.33)%.When the concentration of essential oil was 10%,the hydroxyl radical scavenging rate was 98.29%,which was lower than that of VC at the same concentration,and the DPPH radical scavenging rate was 49.28%,which was much lower than that of VC at the same concentration,but the increase was significant.At the same volume concentration,essential oil had obvious inhibitory effect on Staphylococcus aureus and Escherichia coli.Therefore,pomelo peel essential oil had excellent antioxidant and antibacterial activities,which could be further developed into a natural preservatives for food processing and preservation.