In this work, the calcium alginate microcapsules containing lemon oil were prepared by emulsification-internal gelation, and their potential use as aromatherapy was examined by the controlled release system. The lemon oil encapsulated in the alginate was successfully observed by Fourier transform (FT-IR) spectroscopy and differential scanning calorimeter (DSC) measurements. Analysis of the diameters and shapes of microcapsules was conducted by scanning electron microscopy (SEM). The mean diameters ranging from 4 to 7 μm and encapsulation yield ranging from 50 to 85% were obtained. The controlled release of the lemon oil at 37 ℃ was demonstrated by the infrared moisture determination (IMDB). It was found that the amount of released lemon oil decreased with increasing concentrations of alginate and CaCl2 due to the higher the cross-linking density of the capsules prepared. The oil release from the capsule was measured as a function of physical force. We confirmed that the external factor could control the collapse of capsule wall and the release rate.

본 실험에서는 레몬 오일을 함유한 알긴산 칼슘 마이크로캡슐을 에멀션-내부 젤화법으로 제조하였으며, 방출실험을 통하여 아로마테라피의 가능성에 대해 살펴보았다. 적외선분광분석(FT-IR)과 시차주사열량계(DSC)를 통해 레몬 오일의 봉입 여부를 확인하였고, 제조된 마이크로캡슐의 직경 및 형태를 주사전자현미경(SEM)으로 관찰하였다. 제조된 마이크로캡슐은 평균 4~7 μm 직경 및 50~85%의 캡슐화를 보였으며, 37 ℃에서 적외선 수분계(IMDB)를 통한 방출실험 결과, 알긴산 및 CaCl2의 농도가 증가할수록 가교밀도가 증가하므로 레몬 오일의 방출률이 감소함을 관찰할 수 있었다. 또한, 물리적 압력을 통한 방출실험을 실시함으로써, 캡슐벽의 붕괴와 방출속도가 외부적인 요인에 의해 방출속도를 제어 할 수 있음을 확인하였다.

Keywords: calcium alginate; microcapsule; emulsification-internal gelation; infrared moisture determination