Fabrication Of Vanillin Ternary Complexes Microparticles And Their Application In Bread

Vanilla is one of the most widely used flavors and is the primary source of vanilla flavor.In addition,vanillin has multifunctional properties including anticancer,antibacterial,antioxidant and anti-inflammatory activity.However,the physiological function and application of vanilla in the food industry is compromised by its naturally occurring limited water-solubility,thermal instability and volatility.The solubility,stability and biological activity of the bioactive substances could be improved by the binary complex formed via the self-assembly of biopolymer and bioactive substances.Recently,research suggests that ternary complexes are often better than binary ones at enhancing the functional performance of bioactive substances.However,there is currently limited knowledge regarding the fabrication,formation and physicochemical characteristics of vanillin-based ternary complexes.Therefore,in this study,vanillin ternary complex microparticles were fabricated with vanillin,γ-cyclodextrin and dextran as raw materials.The effects of the composition of ternary complexes on the solubility,thermal stability and controlling release of vanillin were investigated.Finally,the effects of complex microparticles on the shelf life of bread were investigated.The main findings were as follows.Vanillin/γ-cyclodextrin/dextran(V/C/D)ternary complex microparticles were prepared by self-assembly and spray drying method.In the complex microparticles,vanillin is bound toγ-cyclodextrin by hydrogen bonds and hydrophobic interactions,and dextran is bound to vanillin by hydrogen bonds.The pore size of the microparticles is mainly concentrated at 5 nm,the specific surface area is concentrated in 0.905-1.264 m~2/g,and the pore volume is concentrated in 0.005-0.007cm~3/g.Compared with the binary complex(V/C/D 1:9:0),the ternary complex(V/C/D 1:5:4)significantly improved the encapsulation efficiency and loading capacity of vanillin.The encapsulation efficiency increased from 58%to 92%,and the loading capacity increased from 5.9%to 9.2%,which may be related to the more complete structure of ternary complex and lower probability of breakage.Moreover,the crystallization peak of vanillin disappeared in complexes with higher dextran contents.The effects of the composition of complex microparticles on the water solubility,stability and controlling release of vanillin were investigated.The results showed that the solubility of vanillin in cold water was improved by ternary complex microparticles,and the solubility increased with the increase of dextran content.The solubility of vanillin encapsulated in complex microparticles(V/C/D 1:3:6)in water at 4℃was up to 15 mg/m L,4 times that of vanillin crystals.With the increase of dextran content,the thermal stability of vanillin was further improved.After storage at 60℃for 30 days,the vanillin crystal retention rate was 13%,but the vanillin retention rate of ternary complex microparticles(V/C/D 1:5:4 and V/C/D 1:3:6)was still more than 90%.The stability of vanillin was improved at 200℃,and the release rate of vanillin decreased with the increase of dextran content.The results can provide some reference value for the application of vanillin ternary complex microparticles in cold drinks and baked food.The effects of vanillin retention rate on the shelf life of bread were investigated.The vanillin retention rate of ternary complex microparticles(V/C/D 1:5:4)after bread baking was 70%,which was 2.8 times that of vanillin crystal.During storage,the acid value and peroxide value of breads without vanillin exceeded the national standard on the 4 day,while breads containing complex microparticles(V/C/D 1:5:4)exceeded the national standard on the 7 day.From the changes in the appearance of the bread,it was found that the bread without vanillin had mold spots on the 4 day,and the bread containing complex microparticles(V/C/D 1:5:4 and V/C/D 1:3:6)had mold spots on the 7 day.From the analysis of the total number of colonies,it was found that the microbial index of the bread without vanillin exceeded the national standard on the 6 day,while breads containing complex microparticles(V/C/D 1:5:4and V/C/D 1:3:6)still met the national standard.These results were mainly attributed to vanillin in the complex microparticles inhibiting the growth of Bacillus and Aspergillus flavus,thereby extending the shelf life of the bread.