執行成果摘要
In this study, hydrodistillation (HD), steam distillation (SD), microwave distillation (MD), and supercritical carbon dioxide extraction (SC-CO2) techniques were evaluated for their effectiveness in isolating essential oil and antioxidant activities of milled particles of the thinning logs of Calocedrus formosana Florin harvested from Lienhuachih Research Center. Results showed that the HD and SD are always tedious and time consuming. MD can focus directly onto the sample, shortening extraction time considerably, while reducing energy consumption and producing higher efficiency than those of conventional methods. Five extractive compounds were identified by GC-MS, and the main component was α-Pinene, Myrcene, Limonene etc. Response surface methodology (RSM) was used to optimize the supercritical carbon dioxide (SC-CO2) extraction of essential oil from ground Calocedrus formosana. The extraction yields were firstly evaluated by single factor test, a three factors and three levels, namely. extracting pressure (30-38 MPa), temperature (45-55℃) and extraction time (1.2-2.0 hr) for the multiple testing. Utilizing the Box-Benhken central composite design (CCD) to optimize the parameters and the yield of Calocedrus formosana oil was used as the responsive values. The RSM was employed to analyze the resulting of experiments and optimized by the Design-Expert. A second-degree polynomial regression equation reflecting the relationship between the extraction rate and the above mentioned extraction parameters was established and the optimal extraction process conditions were obtained by RSM analysis. ANOVA (analysis of variance) showed that all three factors had a positive correlation, the pressure affected the extraction yields most significantly, followed by the temperature and extraction time. Application of the RSM analysis showed that optimal operational parameters were established from Calocedrus formosana were: extraction pressure was 38.6 MPa, extraction temperature was 51 ℃, extraction time was 1.4 hr. Under above mentioned optimum condition, the extraction yield was 1.38 %. The result was verified and the correlation coefficient between the measured value and predicted value was 0.989. Screening trials of Tyrosinase inhibitory activity with all extraction (500 μg/mL) from wood showed the favorable results and test results indicate leaves essential oil has good effect on Xanthine oxidase. In addition, the development of microwave extraction had been with a new style patent, and there was interest of technology transfer to private sector uses.