GC-MS analysis and antioxidant and antimicrobial properties of volatile oil from flos magnoliae

The volatile oil of Flos Magnoliae was extracted by simultaneous distillation extraction method (SDE), hydrodistillation method (HD) and static headspace method (SH), respectively. Quantitative analyses of volatile oils were carried out by retention index using gas chromatography-mass spectrometry (GC-MS) combined with database searching. To compare the volatile oils extracted with the HD and SDE methods, we used Prussian blue method and the Neocuproine method to examine their antioxidant activities, used 2,2-diphenyl-1-picrylhydrazyl (DPPH) to determine their free radical scavenging abilities, and used the filter paper method and the 96-well plate method to measure their antibacterial activities. The results showed that a total of 66 chemical compounds were identified in the volatile oils extracted with the above three methods, 17 compounds of which were common to the three oils, showing significant differences in the relative amount of each of them. A total of 47, 43 and 26 volatile compounds were identified in the oils extracted with HD, SDE and SH, respectively. The composition of volatile compounds extracted with HD and SDE was similar, while SH extracted the smallest number of compounds. The Flos Magnoliae volatile oils extracted by HD and SDE showed an obvious antioxidant activity, as well as the ability to inhibit Staphylococcus aureus, Listeria monocytogenes, Escherichia coli and Salmonella typhimurium, especially Gram-negative bacteria. The antioxidant activity and antibacterial activity showed the potential usage of Flos Magnoliae volatile oils as natural food preservatives in the pharmaceutical and food industries. © 2016, China Food Publishing Company. All right reserved.