Preparation Of Short Glucan Chain And Study On Its Molecular Inclusion Behavior Of Curcumin

In this paper, the method of enzymatic hydrolysis was used to prepare short glucan chain, then the preparation processes of short glucan chain-curcumin inclusion complex and short glucan chain-curcumin nanoemulsion were studied by means of experimental preparation and molecular dynamics simulation. Moreover, the interactions and conformational changes were evaluated.Four short glucan chain samples were prepared using enzyme hydrolysis. Then the degree of polymerization, apparent morphological, crystallinity ,thermal stability and structural analysis were determined. The average DP (degree of polymerization) values of each short glucan chain sample were about 17 and the average DP value of SC2 is the smallest (i.e. 16.79). The morphologic characteristics of the native waxy corn starch and the short glucan chains were observed by SEM and TEM. The morphology of the native waxy corn starch displayed ellipsoidal shape with a diameter of approximately 300 nm. But the morphology of the short glucan chains displayed erosion at the scene. The particle sizes of short glucan chain were about 250 nm. The crystalline structures of samples were analyzed using X-ray diffractometer. The relative ciystallinity of native waxy corn starch was 33.70% and type of diffraction pattern was A-type. The type of diffraction patterns of four short glucan chains were both B+V type and the relative of crystalline of SC2 was the smallest (i.e. 26.20%). The maximum degradation rate of native waxy corn starch was around 321.09?. There was no significant difference in the thermal stability of the four short glucan chains and the thermal stability of SC2 was slightly better than that of the other three samples. The infrared spectra of native waxy corn starch and short glucan chains were investigated, it was found that in the process of enzymolysis the ?-1,6-glycosidic bonds were hydrolysed and created hydroxyl groups and then formed hydrogen bonds. Therefore, SC2 is more suitable for encapsulating curcumin than the other three samples.The short glucan chain-curcumin inclusion complex was prepared by a simple solution blending method. Then the formation of inclusion complex was confirmed. However, the encapsulation efficiency and loading content were low, the inclusion complex had a poor thermal stability. The morphology of the inclusion complex was not only different with the high crystalline form of curcumin, but also different with the morphology of SC2. The particle sizes of the inclusion complexes were more than 1000 nm and the particle size distributions were not uniform. The solubility of the inclusion complexes was still poor.In order to overcome the shortcomings of the above-mentioned inclusion complex, the preparation process was improved and the short glucan chain-curcumn nanoemulsion was prepared.The results showed that the obtained emulsion had a good solubility. The particle sizes of the prepared nano-emulsion were less than 1000 nm and the particle size distributions were uniform.The prepared emulsion had a degree of stability, but need to be further improved. The encapsulation efficiency and loading content were significantly improved.Molecular dynamics (MD) simulation were used to monitor the actions of the assembling of the system and intermolecular forces. It suggests that the presence of curcumin increases the hydration of short glucan chains. Therefore, to a certain extent, it improves the solubility of curcumin which was encapsulated.