| Emulsion-spray drying and beta-cyclodextrin(β-CD) are two kinds of technology of flavormicroencapsulation, and the emulsion-spray drying is a traditional method, β-CD is a newlymethod. The storage stability and high temperature resistant characteristic of microencapsulatedflavor prepared by different methods are compared, it is purpose to quest for the further researchon microencapsulated flavor possessed high temperature resistance.The microencapsulated sweet orange oil of high temperature resistant characteristic preparedby using emulsion-spray drying was investigated. Different wall materials and effect of theprocessing parameters on the microencapsulation efficiency and yield were compared. It showedthat the products with high quality could be obtained at the optimal conditions such as the wallmaterial of modified starch 3, the solid concentration of 40%, inlet temperature of 185℃ andoutlet temperature of 85 ℃.The microencapsulation of sweet orange oil complexed with β-CD was studied. It showed thatthe products with high quality could be obtained at the optimal conditions such as suspensionmethod, the temperature of 55 ℃, time of 6 hours and load of 5%.In addition, differentialscanning calorimetry (DSC), Nuclear Magnetic Resonance(NMR) and Infrared (IR) techniquesresults revealed that complexation did occur between sweet orange oil and β-CD。The release characteristics of microencapsulated sweet orange oil during storage wereevaluated. The results showed that the release rate at 75% of relative humidity was faster thanother relative humidity. And at the same humidity the release rate of sample prepared by usingemulsion-spray drying was faster than another product. Scanning electron microscopy(SEM) wasapplied to the microstructure study of microcapsules, and it is clearly indicated that the powderprepared by spray drying were relatively spherical and more regular, and the particle size andstructure of powder prepared by using β-CD were irregular.The release of microencapsulated sweet orange oil prepared by different methods werecompared on high temperature, it is showed that the release rate of product made by usingspray-drying was faster than by using β-CD method at 180℃and 200℃ temperature, but it isdifferent at 100℃,120℃,140℃ and 160℃ temperature. The headspace results indicated thatflavor in headspace released from microencapsulated sweet orange oil after heating is differentdue to heating temperature and preparing method, and the release characteristic evaluated byheadspace is accord with heating retention. The microstructure of microencapsulated sweetorange oil after heating reveals that the product structure prepared by emulsion-spray drying hasbeen destroyed, and the product prepared by β-CD has no difference after heating.The microencapsulated sweet orange oil was added to the bake product, and the fuzzymathematics method combined with sensory evaluation was used to evaluate biscuit, it is showedthat microencapsulated sweet orange oil was better than other flavors. The release on hightemperature was analyzed by Avrami's Equation. |
