초임계 이산화탄소를 이용한 참깨박에서 추출된 오일의 특성

Abstract

The sesame cake contains a high content of valuable polyunsaturated fatty acids and polyphenol which have the antioxidant characteristics with great potential health benefits such as reducing the risk of cardiovascular disease and cancer. Polyphenol are generally further subdivided into tannins, and phenylpropanoids; lignin’s and flavonoids. Previous studies showed that the use of high temperature required for organic solvent extraction was not efficient due to the materials oxidization. However supercritical carbon dioxide (SCO2) extraction can offer a non-oxidative environment due to the low critical temperature (31.05℃) which makes it suitable for processing the thermal sensitive materials. In this work, the extraction of sesame cake oil using SCO2 was performed under the conditions range of pressure and temperature of 15 to 25 MPa and 35 to 55℃ respectively. The flow rate of carbon dioxide (23 ml/min) was constant entire the extraction period. The maxwaum oil yield was found at the higher extraction pressure and temperature (25 MPa and 55℃). The solubility of sesame cake in SCO2 was found to be increasing with the increase of temperature. The fatty acids composition was analysed by Gas Chromatography (GC) and the extracts showed a high amount of the saturated fatty acids especially palmitic acid. For the unsaturated fatty acids, linoleic and oleic acid showed the highest percentage in all extraction conditions. Also, polyphenol was quantitatively analyzed using UV-spectrometerly anathe extracted oil at different experimental conditions. The total phenolic content (TPC) in the extracts was compared with that obtained by hexane extraction. The highest TPC was 722 ppnaat 25 MPa and 45℃ SCO2 extraction. However, it was 267 ppnain the extracts obtained by hexane extraction. On the other hand, AV and POV of hexane extracted oil were slightly higher than that extracted by SCO2 showing high amount of polyphenol comparing with the hexane extracted oil. In rancimat test, sesame cake oil extracted by SCO2 had longer induction period than obtained by hexane. The longest induction period was 10.2h at 25 Mpa and 35℃. The result of DPPH radical scavenging effect was excellent. In general, sesame cake oil showed appreciable free radical scavenging activities. And 25 MPa and 45℃ extracted oil had strongest radical scavenging. These results caused by high amount of antioxidant materials, such as TPC. The oil obtained at 25 MPa and 45℃ showed high antioxidant activities.