Study On Preparation And Antibacterial Activity Properties Of Tea Tree Oil Nanoparticles

Tea tree oil(TTO)is widely used because of its effective property bacteriostatic activity.It is from paper bark tea trees,which belongs to Myrtaceae.Paper bark tea trees originally grew in Australia,and now have been planted in many other countries and regions in the world including Guangdong,Guangxi and other places of China.TTO,however,is not easy to be stored because of its volatility.In this study,the TTO was stored by nanoparticles,which not only extended TTO's storage time,but also avoided the loss of TTO's effective materials in the process of preparing microcapsules.This study uses TTO that produced in Guangxi as a core material.And stevioside as the main wall material and maltodextrin as wall material compound.TTO nanoparticles were prepared for trial by composite condensation method and solvent evaporation method.With the consideration of the advantages and disadvantages of the two methods,the composite condensation method was finally chosen for preparing the TTO nanoparticles.The following factors in the preparation,such as mixing time,the homogeneous time,the ratio of core wall material,the proportion of the wall material,the type and amount of emulsifier,the amount of curing agent,etc.were studied by the composite condensation method.And process conditions were optimized by response surface analysis method,the best preparation conditions of TTO nanoparticles were found.To ensure the successful preservation,TTO nanoparticles were examined in their particle sizes,particle size distributions,onlookers shapes,package buried rates,the retention time lengths of the active substance in TTO nanoparticles,and several other factors.By complex coacervation method and with the core and wall materials ratio of 1:10,stevioside and maltdextrin(of a ratio of1:1)as the wall materials,the additions of 1.0% emulsifier(Tween 80: Span 80=3:1)and0.6% curing agent,5 minutes' homogenization,60 minutes' stirring and dry it by rotary evaporator.TTO nanoparticles with sizes of 110nm±10 nm and embedding rates of88%±2% were obtained.Oils from the paper bark tea trees in different places are different in constituents.This study analyzed and compared the main constituents and the antibacterial effects of the TTOs from Guangxi,Guangdong and Australia.It was found that although all the TTOs from different places had antibacterial effects,they had different antibacterial effects on differentbacteria because of their different constituents.