Preparation And Characterization Of Slow-release Fragrance Based On β-cyclodextrin Cavity Structure

As functional additives,flavors and fragrances have been widely used in people’s daily necessities to bring a pleasant feeling.Many chemical components of flavors and fragrances are unstable,volatile and prone to deterioration when exposed to light and heat in the air.β-cyclodextrin(β-CD)is a cyclic oligosaccharide with 7 glucose unit molecules.Due to its properties of safe,non-toxic and biodegradable,it can be used as an environmentally friendly wall material to encapsulate various guest molecules to improve the solubility of guest molecules,effectively improve its stability and prolong the aroma retention time to achieve controlled release.In this study,apple fragrance was used as a model to prepare fragrance/β-CD inclusion complexes.During the preparation process,the influence of temperature,time,ratio of core to wall,addition of wall materials and stirring rate on encapsulation was investigated with encapsulation efficiency(EE%),loading capacity(LC%)and the particle size as indicators.In addition,the correlation between reaction parameters and the encapsulation efficiency,loading and particle size were analyzed by the model which was established by partial least squares(PLSR).The optimal preparation conditions for preparing apple fragrance/β-CD inclusion complex were obtained as follows:the ratio of apple fragrance toβ-CD was 1:10,the temperature was 50~oC,the time was 3 hours,the addition of wall materials was 10%and the stirring rate was 800 rpm.In these conditions,the encapsulation efficiency of the apple fragrance/β-CD inclusion complex was 79.8%,the loading capacity was 6.78%,and the particle size was 3.6um.The apple fragrance/β-CD inclusion complex was characterized by scanning electron microscopy(SEM)and Fourier transform infrared spectroscopy(FTIR).The thermal stability of the apple fragrance/β-CD inclusion complex was analyzed by thermogravimetric analyzer(TGA)and differential scanning calorimetry(DSC).The Avrami equation was used to fit the release kinetics of apple fragrance/β-cyclodextrin inclusion complex at different temperatures.It was found that the release performance was between diffusion limiting kinetics and first-order release kinetics at 4°C.At 25 and 50~oC,it was first-order release kinetic mode.Finally,the apple fragrance/β-cyclodextrin inclusion complex obtained by the optimum preparation conditions was applied to cotton fabric through impregnation.Then the aromatic cotton fabrics was obtained with a bath ratio of 1:20.The aromatic cotton fabrics was characterized by scanning electron microscopy(SEM).The results showed that the surface appearance of the blank cotton fabrics was smooth,a large number of particles were adhered to the surface of the cotton fabrics impregnated by fragrance/β-CD inclusion complexes.This confirmed that the fragrance/β-CD inclusion complexes were successfully applied to cotton fabrics.Slow release experiments of the aromatic cotton fabrics performed by gas chromatography-mass spectrometer(GC–MS)and electronic nose(E-Nose)proved that the cotton fabrics impregnated by fragrance/β-CD inclusion complexes had excellent slow release properties.Moreover,the continuous aroma release time of the cotton fabrics impregnated by fragrance/β-CD inclusion complexes reached up to 80 days.