变废为宝——“下岗年桔”精油抗氧化和抑菌活性研究

Turning Waste into Wealth——Chemical Composition,Antioxidant and Antibacterial Activities of Essential Oils of Waste Calamondin

为进一步开发利用四季桔资源,采用水蒸气蒸馏法提取四季桔不同部位精油,利用GC-MS进行化学成分分析,通过DPPH和ABTS测定抗氧化活性,采用抑菌圈和MIC评价抑菌活性,结果表明:桔叶精油(LEO)的主要化学成分是含氧倍半萜(32.74%)和含氧单萜类化合物(32.30%),桔皮精油(青皮IPEO、黄皮MPEO)中主要含有单萜类化合物(>95.00%);LEO、IPEO及MPEO对DPPH、ABTS自由基均显示出明显的清除能力,且有量效关系;在DPPH中的IC_(50)值分别为2.699±0.424,3.013±0.060和4.563±0.275 mg/mL;LEO的抑菌活性最强,对金黄葡萄球菌、沙门氏菌、李斯特菌、大肠杆菌的抑菌圈大小依次为32.20,27.13,28.53和26.76 mm,MIC为1.88,1.88,30和1.88μL/mL;IPEO的抑菌活性次之,MPEO抑菌活性最弱;三种精油的抗氧化和抑菌活性强弱顺序一致。四季桔精油可作为天然防腐剂和抗氧化剂进一步开发利用。

The essential oils(EOs)extracted from the leaves(LEO),immature peel(IPEO)and mature peel(MPEO)of Calamondin by water-distilled were analyzed by gas chromatography-mass spectrometry(GC-MS),and their antioxidant and antibacterial activities were investigated.The peel essential oils(IPEO and MPEO)primary contained monoterpene hydrocarbons(>95%),while oxygenated sesquiterpenes(32.74%)and oxygenated monoterpenes(32.30%)were the main components of the leaf oil.LEO,IPEO and MPEO showed obvious antioxidant activities with the relation of dosage-effect in DPPH and ABTS tests,and the IC_(50) of them were 2.699±0.424,3.013±0.060 and 4.563±0.275 mg/mL in DPPH test.LEO had particularly strong antibacterial activities against S.aureus,S.typhimurium,L.monocytogenes and E.coli,the diameter of inhibition zone were 32.20±0.20,27.13±0.15,28.53±0.25 and 26.76±0.35 mm,and the minimum inhibitory concentration(MIC)were 1.88,1.88,30 and 1.88μL/mL respectively.The order of antibacterial activities of the 3 different parts was LEO>IPEO>MPEO,which was the same as the order of their antioxidant activities.The results demonstrated that the essential oil from Calamondin was a potential natural additive for food preservation.