| With a growing number of food safety incidents occurred, more and more food additives traditional and synthetic were found dangerous to the body recent years, which frequently influenced and even endangered human being's life. As we all know, both food preservative and antioxidants play important roles in the Food Additives Industry. Therefore, it's essential to establish a sound management system to ensure the safety of these two additives and develop more natural food additives with high safety, low toxicity and beneficial effects, which will also be an inevitable trend in the Food Industry. Based on various medicinal value, the aromatics have been proved that not only the oils can inhibit the growth of bacterial as well as preventing the oxidation, but also the non-oil components have good antioxidant activity.Three aromatic plants, Myrtle, Lavender Mint and Rosemary, were researched in the present study, which were successfully introduced to Shanghai in recent years, including lavender mint, a new species. Firstly, the method of steam distillation was used to extract essential oils from dry leaves of three aromatics, respectively. Then solvents such as distilled water, ethanol, methanol-water and ethyl acetate were selected to extract non-volatile components from their residues. The antimicrobial effect of oils and non-volatile components were measured and compared by the method of agar diffusion. By changing the pH, temperature and UV irradiation, the oils'antimicrobial stability was also detected. Furthermore, GC/MS was used to analysis the volatile components. In addition, three chemiluminescence systems and one colorimetric system were founded to evaluate the capacity of scavenging free radicals and inhibiting oxidation of three oils systemically. The results revealed that all three oils could inhibit the bacterias with broad spectrum and great stability, among which the inhibition effect of lavender mint was significantly better than the others', while antimicrobial activity of the other two oils was very close to each other.In contrast, the antimicrobial sensitivity of non-volatile components was lower than the oils, among which the inhibition activity of aqueous extracts was the lowest. It suggested the effective ingredients presented in the organic solvent extracts. Furthermore, the antimicrobial capability indicated myrtle> rosemary> lavender mint for the non-volatile part.The results showed that bacteriostasis of volatile oils were much more effective than the non-volatile components, which indicated that antibacterial components of these three aromatics presented in the disitilled oil.Besides, GC/MS analysis revealed there were sorts of active ingredients in the oils, including terpenes, alcohols, esters, ketones, alkanes and so on. What was more, there were also several common components contained in the oils, such as Linalool, 1,8-Cineole, Norbornane and so on. Most of the chemical constituents were terpenes. And the terpenoids contained were analyzed Myrtle 59.80%, Lavender Mint 79.63%, Rosemary 60.36%, which accorded with the antibacterial activity of the three oils. It suggested the terpenoids were important for inhibiting the bacterias.Data of antioxidation indicated that the oils showed varying degrees of scavenging O2-',·OH, CO3-·and DPPH·, with certain dose-effect relationship. Compared with the nonessential oils we studied before, the oils showed weaker ability on scavenging free radical and antioxidation in these three aromatic plants, which indicated that the effective components mainly exsit in the nonessential parts.All above results suggest that Myrtle, Lavender mint and Rosemary are good aromatic plants with effective antimicrobial and antioxidant effect. Both the oil and non-oil part are available resource to the Food Industry. They should be considered as good candidates for further development of natural, harmless and green food additives. The present research provides an important theoretic base for the application study of new food additives.
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