Research On The Volatile Compounds And Essential Oil Bioactivities Of Jin Bergamot

In this research,the essential oil was extracted by ultrasound-assisted hydrodistillation(UAHD)and supercritical carbon dioxide fluid extraction(SFE-CO2)from the fruits of Bergamot(Citrus medica L.var.sarcodactylis(Noot.)Swingle),analyzed by GC-MS;the volatile compounds in air of Bergamot was collected by headspace solid phase microextraction(HS-SPME)and analyzed by GC-MS;the antioxidant activity of Bergamot essential oil(BEO)was measured by FRAP assay for reducing power,ABTS assay for radical scavenging activity and superoxide anion radical(O2·-)scavenging activity;the antimicrobial activity of BEO was measured by minimum inhibitory concentration(MIC)and minimum bactericidal or fungicidal concentration(MBC/MFC)determinnations.The main results are as follows:With the univariate experiments and response surface methodology(RSM),the optimum UAHD techniques were confirmed:ultrasonic time 60 min,distillation time 4h,the ratio of water to material 1:9.5,and the BEO extracting yield reached 0.57%,UAHD techniques increased the oil yield.Chemical components were obtained by SFE-C02 and UAHD from the fruits of Bergamot and compared using GC-MS.Terpenes were the main substances of BEO extracted by UAHD,and the major chemical were D-Limonene(60.44%),y-Terpinene(20.28%).Acids were the main substances of BEO extracted by SFE-C02,and the major chemical were Linoleic acid(65.61%)Hexadecanoic acid(12.56%)and Citropten limettin(10.52%).According to a contrast and analysis,the author found that the chemical composition and percentage of content was quite different.41 volatile compounds in HS-SPME were analyzed by GC/MS,the major components were identified as D-Limonene(34.81%),β-Caryophyllene(9.91%),α-Bergamotene(8.33%),γ-Terpinene(5.54%),α-Terpineol(5.53%),β-Bisabolene(5.51%),β-Cubebene(2.82%),Elixene(2.27%)and m-Cymene(2.15%).Compared to the chemical compounds of BEO,the volatile compounds in HS-SPME were more complicated,but the main components were similar.In addition,the research find that the main odor characteristics of Bergamot was fruit and woody aromas.This research studies on antioxidant and antimicrobial activities of BEO.BEO showed significant antioxidant activities according to FRAP assay for reducing power,ABTS assay for radical scavenging activity and Superoxide anion radical(O2·-)scavenging activity.BEO has a better ABTS assay for radical scavenging activity than FRAP assay for reducing power and Superoxide anion radical(O2--)scavenging activity.Take Escherichia coli,Bacillus subtilis,Staphylococcus aureus,Micrococcus luteus and Yeast as tested microorganisms,determinated the MIC、MBC/MFC,we can find the order as follow:E.coli>S.aureus=Yeast>M.luteus=B.subtilis.Through the research of antimicrobial activities of five tested microorganisms to various concentrations of BEO,we can obtain the antimicrobial activities with the BEO concentration,showing a rising trend,but different increasing rates during different strain.In higher concentrations,BEO can entirely inhibit the growth of tested microorganisms.In lower concentrations,inhibition of BEO on E.coli was best,the following were M.luteus,S.aureus,Yeast and B.subtilis.