Research On The Preparation And Characteristics Of Osmanthus Essential Oil Microcapsules By Interfacial Polymerization

Osmanthus essential oil,as a unique natural plant essential oil in China,not only has pleasant fragrance,but also has edible and medicinal functions and a variety of physiological activities.However,the quality of osmanthus essential oil can easily be affected by environmental factors when it is exposed to the air.It is prone to oxidative rancidity and volatilization.In this paper,the interfacial polymerization method was used to prepare osmanthus essential oil microcapsules(OEOM),which may improve the storage stability of osmanthus essential oil,change the physical state of osmanthus essential oil and expand the application prospect of osmanthus essential oil in different fields.The main research contents are as follows:The effects of the ratio of osmanthus essential oil to oil monomer N100,reaction temperature and reaction time on microencapsulation of osmanthus essential oil were studied.The optimum preparation conditions were determined by orthogonal experiment:the ratio of osmanthus essential oil to N100 was 6:1,the reaction temperature was 70?,and the reaction time was 2 h.The embedding rate of microcapsules of osmanthus essential oil can reach 80.31%under this condition.The OEOM were characterized by particle size analysis,scanning electron microscopy(SEM),rheological test,thermogravimetric analysis(TGA)and Fourier infrared spectroscopy(FTIR).The results showed that the average diameter of the microcapsules were 101.2 ?m,and the microcapsules had a full spherical shape,smooth surface,low viscosity and high elasticity.The microencapsulation of osmanthus oil could improve the thermal stability of the oil,and the decomposition temperature increased from 415.99? to 427.33?.The results of FTIR analysis confirmed the existence of amide structure(-NH-CO-NH-).The release kinetics and storage stability of OEOM were studied.The results of release kinetics showed that the total amount of core materials released in SDS solution for 5 h were less than 10%.The release kinetics equation was y=1.4213x0.3335,and the correlation coefficient was R2=0.9956.The results of storage stability showed that the retention rate of OEOM under four different storage conditions were 82.14%-89.78%.Considering the economic factors,the OEOM could be stored at room temperature with darkness(the retention rate was 85.99%).The synthesis of the composite membrane microcapsules was studied.The composite membrane microcapsules were characterized by optical microscopy,particle size analysis,energy dispersive spectrometer(EDS),SEM and rheological test.The results showed that the composite membrane microcapsules presented elongated "ear" shape with an average diameter of 146.0 ?m.Its N element weight percentage is 36.30,and the capsule has high viscosity,low permeability and instant release ability.