Microchannel emulsification using gelatin and surfactant-free coacervate microencapsulation.
In this study, we investigated the use of microchannel (MC) emulsifications in producing monodisperse gelatin/acacia complex coacervate microcapsules of soybean oil. This is considered to be a novel method for preparing monodisperse O/W and W/O emulsions. Generally, surfactants are necessary for MC emulsification, but they can also inhibit the coacervation process. In this study, we investigated a surfactant-free system. First, MC emulsification using gelatin was compared with that using decaglycerol monolaurate. The results demonstrated the potential use of gelatin for MC emulsification. MC emulsification experiments conducted over a range of conditions revealed that the pH of the continuous phase should be maintained above the isoelectric point of the gelatin. A high concentration of gelatin was found to inhibit the production of irregular-sized droplets. Low-bloom gelatin was found to be suitable for obtaining monodisperse emulsions. Finally, surfactant-free monodisperse droplets prepared by MC emulsification were microencapsulated with coacervate. The microcapsules produced by this technique were observed with a confocal laser scanning microscope. Average diameters of the inner cores and outer shells were 37.8 and 51.5 microm; their relative standard deviations were 4.9 and 8.4%.
Division of Food Engineering, National Food Research Institute, 2-1-12 Kannondai, Tsukuba, Ibaraki 305-8642, Japan.
Kei
K
Nakagawa
Satoshi
S
Iwamoto
Mitsutoshi
M
Nakajima
Atsushi
A
Shono
Kazumi
K
Satoh
D004339:Drug Compounding / Q000295:instrumentation / Q000379:methods*; D045703:Emulsifying Agents / Q000737:chemistry; D004655:Emulsions / Q000138:chemical synthesis* / Q000737:chemistry; D016650:Fluorescein-5-isothiocyanate / Q000737:chemistry; D005780:Gelatin / Q000737:chemistry*; D005990:Glycerol / Q000031:analogs & derivatives / Q000737:chemistry; D006170:Gum Arabic / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D007848:Laurates / Q000737:chemistry; D008856:Microscopy, Fluorescence; D010316:Particle Size; D013024:Soybean Oil / Q000737:chemistry; D013501:Surface-Active Agents / Q000737:chemistry
D045703:Emulsifying Agents; D004655:Emulsions; D007848:Laurates; D013501:Surface-Active Agents; D013024:Soybean Oil; D006170:Gum Arabic; D005780:Gelatin; D016650:Fluorescein-5-isothiocyanate; D005990:Glycerol