Study On Process And Models For Extraction Of Edible And Medicinal Ingredients With Supercritical Carbon Dioxide From Grape Seed

Grape seeds contain seed oil and procyanidins which are generally named plant poly-phenol. Grape seed oil is about 10(15 weight % of the total grape seed and is rich on about 45(72% of linoleic acid which belongs to unsaturated fatty acid and is considered to be beneficial to the health of mankind when the oil high in linoleic acid are used in the fields of food, cosmetic and medicine. Grape procyanidins have been increasingly paid much attention as one of the ten most popular herbal medicines in the world and can be used for medicine, hygienic food and cosmetic due to their biological and pharmacological actives such as anti-oxidation and anti-mutation and so on. Therefore, it is of important social significance and commercial values to investigate extraction of these useful components from the abandoned grape seeds during vintage processes. With occurring the upsurge of savageness, nutrition and returning natural all over the world, supercritical fluid extraction technology holds prominent status in the domain of extraction of natural products as a kind of high effective and clean separation technology. This thesis mainly explores the feasibility and the optimal conditions of extracting seed oil and procyanidins from grape seeds with supercritical carbon dioxide. The process of extracting oil from grape seeds was firstly studied. And the influences of extraction temperature and extraction pressure on the extraction yield of the seed oil were investigated. The optimal extraction conditions were obtained experimentally. Three kinds of grape seeds from different locations were used to make comparison. It is found that the yield of oilseed is up to 13.51% when using the seeds supplied from Dynasty Wine Co. Ltd.. GC/MS analysis shows that the unsaturated fatty acid in the extracted oil is up to 90.1%. The quality test were also carried out and the test results demonstrate that the grape seed oil extracted with supercritical carbon dioxide has totally satisfied with the routine quality index of physical and chemical characters for the refined edible vegetable oil according to the national sanitation standard. It reveals that extracting natural products with supercritical carbon dioxide has obvious predominance.The process of extracting procyanidins were further studied from the remains after extracting oil from grape seeds with supercritical CO2. Three kinds of methods for adding entrainer were further investigated in order to enhance the solvent power of CO2 for increase yield and purity of procyanidins. The three methods include adding entrainer to raw material in static mode, adding entrainer to SC-CO2 in flowing mode and combination of the two modes. The effects of extraction temperature, pressure, the concentration and dosage of entrainers and soaking time on the extraction yield and purity of procyanidins were studied, and the optimum parameters and conditions were finally got. The experimental results show that, adding entrainer to raw material in static mode combined with adding a suitable concentration of entrainer to SC-CO2 in flowing mode may be the best way among the three kinds of methods for adding entrainers. The yield of 11.62% with the high purity of 96.54% of procyanidins can be obtained under the investigated optimal conditions. Compared with the conventional extraction technology, it has evident advantages to extract procyanidins with supercritical CO2. In addition, it is proved that the results of lab-scale experiments can be successfully blown up and the supercritical fluid extraction technology of grape seed oil and procyanidins has excellent foreground.The solubility of grape seed oil in supercritical CO2 was studied with associated models in the thesis. The two improved Chrastil equations and a semi- experiential associated model of y( T, P type were advanced. Considering the associated number k changed with temperature, it was expressed as a function of the temperature in the two improved Chrastil equations. The solubility y in the associated semi- experiential model of y( T,...