The Study Of The Components And The Biological Activity Of The Aroma Constituents From Feijoa

In order to understanding comprehensively about aromatic components of feijoa(Acca sellowiana Berg.),aromatic components of different parts of the different feijoa cultivars were analyzed with headspace solid phase micro-extraction(HS-SPME)combined with gas chromatography-mass spectrometry(GC-MS),and then the biological activity of the essential oil from feijoa leaves is preliminarily investigated in this study.Researching aspects and obtained results included:1.The aromatic components from feijoa leaves were extracted by three different methods(soxhlet extraction,ultrasonic assisted solvent extraction and HS-SPME),then analysised by GC-MS.The results showed that there are 36,26 and 63 compounds identified respectively after extracted by three different methods.There are most aromatic components identified in headspace solid phase micro-extraction,and there are the most true fragrance in headspace solid phase micro-extraction,because of it's direct sample adsorption.The headspace solid phase micro-extraction was proved to be the best method of all.2.To establish the appropriate extraction conditions for the analysis of volatile constituents from feijoa by HS-SPME combined with GC-MS,with 75 ?m CAR/PDMS extraction head adopted as adsorption medium,the sum of peak areas and total peak numbers of the volatile constituents were used as indices to optimize the extraction conditions by using L9(34)orthogonal array design,and the following was range analysis.The optimum HS-SPME parameters were selected as follows: 0.6 g sample,extracted for 50 min at 50 ?,and then desorbed for 6 min.Under these conditions,a total of 88 substances were detected,and 65 substances were identified,accounting for 96.583%.The optimum extraction condition can reflect to the greatest extent the fragrant chemical components of feijoa leaves,and it was proved to be practical.3.The aromatic components of different parts of the different feijoa cultivars were extracted and analyzed with above appropriate HS-SPME condition combined with GC-MS.The results showed that there are all 114,87 and 106 aromatic compounds identified respectively in leaves,fruits and flowers,and there are obvious differences amongst different parts of the different feijoa cultivars.4.The aromatic components from feijoa leaves were extracted by solvent extraction,with ascorbic acid as standard substance,the radical scavenging capacity and lipid peroxidation inhibition power of the essential oil from feijoa leaves were determined.The results showed that the essential oil of feijoa leaves had good antioxidant activities,and it was far stronger than ascorbic acid on O2-· and ·OH scavenging capacity,and slightly lower than ascorbic acid on DPPH· scavenging capacity and lipid peroxidation inhibition power.5.The aromatic components from feijoa leaves were extracted by solvent extraction,and the antibacterial activities of the essential oil were investigated,with Escherichia coli and Ataphylococcus aureus,often used for target bacterium in food sterilization,for experimented bacteria.The results showed that it had certain antibacterial effect both on Escherichia coli and on Ataphylococcus aureus,and the prior showed stronger antibacterial activity than the latter.