CHARACTERIZATION OF FREEZE-DRIED/SPRAY-DRIED PROTEIN-BASED NANOPARTICLES FABRICATED VIA CRYOPROCESSING
Dried nanoparticles were prepared using a technique based on the complex coacervation.An oil-in-water emulsion was stabilized with a gelatin-acacia solution,and the pH of the solution was adjusted to a selected value with acetic acid.A freezing process was applied to control the gelatin-acacia complex coacervation for encapsulating emulsified oil droplets in the freeze-concentrated phase.This is a strategical approach to optimize the properties of nano- microparticles through the tuning of the processing parameters,rather than by changing the chemical compositions.Frozen specimens were freeze-dried or spray-dried,and release tests of a lipophilic ingredient (β-carotene) were conducted with the dried specimens for studying the shell membrane properties.Observation by transmission electron microscopy clarified the formation of 50- to 4000-nm core-shell nano- microparticles,the surfaces of which were surrounded by polymeric membranes.The membrane properties of the particulate systems were dependent on the cooling rate that was used during freezing.For example,when an emulsion with a pH of 4.7 was frozen and freeze-dried,a cooling rate of ?1.0°C/min maximized the encapsulation yield,whereas a rate of ?2.0°C/min was effective in limiting the release rate of the ingredient (β-carotene) from the oil phase through the shell membrane.When specimens were prepared via freezing and spray-drying,significant positive effects on the encapsulation efficiency and release properties were not confirmed.However,freezing could affect on the resultant properties of the dried specimens.The results of this study suggest that the resultant properties of the protein-based particulate systems could be tuned using a freezing operation.This is a potential concept providing a novel strategy for engineering core-shell nanoparticles.
nanoparticle oil encapsulation coacervation freeze-drying spray-drying
Kyuya Nakagawa Hiromitsu Nagao Masayuki Kagemoto
Research Center for Nano-Micro Structure and Science,University of Hyogo,2167 Shosha Himeji,671-2280,Japan
国际会议
The 18th International Drying Symposium Conference(第十八届国际干燥学术大会(IDS2012))
厦门
英文
1-6
2012-01-11（万方平台首次上网日期，不代表论文的发表时间）