| Summary: | 碩士 === 國立中興大學 === 化學工程學系所 === 103 === In this study the supercritical carbon dioxide antisolvent (SAS) co-precipitation method is applied to sucrose palmitic acid esters (SE) and propolis to produce water soluble propolis coating. The first step is to investigate the impacts of supercritical antisolvent pressure (120, 140 bar), temperature (33oC), time (10, 20 min), feed flow rate (0.2, 0.5, 0.8 ml/min) and the feed concentration ratio between propolis and SE (3, 4) on the total yield, drug content, and flavonoids recovery rate of the coating. The results revealed that the feed flow rate of 0.5 ml/min has led to better total yield, drug content, and flavonoids recovery rate. The antisolvent pressure and time have not led to significant impacts on total total yield, drug content, and flavonoids recovery rate, yet there is a significant difference in the feed concentration ratio. Therefore the bivariate response surface methodology (RSM) has been applied to obtain the optimal conditions of temperature (33, 43, 53 oC) and feed concentration ratio (3, 4, 5) of SAS with operation conditions of pressure at 120 bar, time at 10 min, and feed flow rate at 0.5 ml/min. The results indicate that the optimal responses predicted by RSM are the feed concentration ratio of 3.71 and the temperature of 53oC, which lead to the total yield of 55.4%, the drug content of 22.9%, and the flavonoids recovery rate of 54.4%, all of which are similar to the experimental values. The RSM results reveal that antisolvent temperature does not lead to any significant impact, while the feed concentration ratio can result in more significant impact on the total yield, drug content, and the flavonoids recovery rate of SAS coating. The result of dissolution rate experiment based on pH 7.4 simulated intestinal fluids indicated that coated propolis dissolved better than acetone extracts of propolis. This indicates that the bonding generated from the co-precipitation between water soluble SE and propolis can enhance the solubility of propolis. Thus the SAS co-precipitation of SE and propolis can be applied to produce water soluble propolis in order to improve the applicability of propolis among health foods.
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