Preparation Technology, Controlled Release And Wall Material Property Of Sweet Orange Oil Microcapsules Using Gelatin And Peach Gum As Wall Mateiral By Complex Coacervation

Coacervate microcapsules can remain whole structure in thehigh-temperature and high-moisture processing environment, releasing slowlyinterior core material. In the method of the preparation of microcapsules bycoacervation，The most commonly used wall material are gelatin and gum arabic,and gum arabic cost is higher，use of cheap gum peach instead of the traditionalgum arabic, study on preparation technology，controlled release and wallmaterial property of gelatin and gum peach coacervate microencapsulation，getthe expected results.In this paper, the microcapsules containing sweet orange oil were preparedby coacervation, using gelatin and gum peach as wall material and sweet orangeoil as core material. The effect of various processing parameters, including thedifferent wall material composition, such as gum arabic, gum peach, gelatin,core/wall ratio, wall material concentration, pH value, stirring speed, emulsiontime, emulsion speed on the morphology, particle size, yield of coacervatemicrocapsules was investigated. From the experiments, it was considered that theoptimal conditions as follows: gum peach/gelatin ratio of1:1,core/wall materialratio of1:1,wall material concentration of0.5%,pH4.0and stirring speed of300rpm,and emulsifying for5min at12000rpm.Study on microcapsules in different preparation technology, release mediumand auxiliary condition for research. The results shows that: In the microwaveheating conditions，microcapsules with different wall materials composition andcore materials composition, core materials of microcapsules were release throughthe diffusion modes,in the process of releasing, the capsule wall was complete,when microcapsules of not hardened and not fully hardened, with the extension ofheating time, wall materials were ruptured and core materials were released; corematerials of microcapsules were release in different ways in different medium, inhot water or in alcohol were release through the diffusion modes;in simulatedgastric fluid, wall materials were ruptured and core materials were released; Pancreatic enzyme in simulated intestinal fluid can accelerated the destruction ofthe microcapsule wall, core material was almost completely released; in differentauxiliary condition, microwave heating and ultrasonic crusher both canaccelerated the destruction of core material released, but wall materials had notbeen destroyed, core material was release through the diffusion modes,microwave heating releasing effect was more obvious than that of ultrasoniccrusher.Different wall materials complex nature of the coacervate were stueied. Theresults showed that， the net potential, viscosity, absorbance and productivity ofcoacervate were all maximum at pH4.0. FT-IR spectrum proved that thecoacervate was formed by the physical interaction between gelatin and gumarabic, not chemical interaction.After hardened by TG, the content of gum arabicin the coacervate decreased and the chemical bond among gelatin molecules wasformed. Through the observation of surface structure of microcapsules byscanning electron microscope showed that microcapsules of peach gum/gelatinratio1:1, the surface was smooth and the capsule wall was complete through sprydrying; TGA curves showed that the hot volatile of microcapsules with differentwall materials composition were lightly different, heating15min at150℃,therelease rate of microcapsules of peach gum/gelatin1:1was about4%.