| Using kiwifruits seed as raw materials and applying modern high-tech food engineering technology, mainly supercritical CO2 extraction-distillation technology, molecular distillation technology, urea inclusion technology, microencapsulation technology etc, kiwifruit seed oil was extracted from kiwifruits seed, a-linolenic acid of kiwifruit seed oil was enriched and kiwifruit seed oil was microencapsulated. The solubility of kiwifruit seed oil and its fatty acids ethyl esters in supercritical CO2 were studied. The conditions and effects of enrichment purified technological on kiwifruit seed oil a-linolenic acids contents were investigated. The technology for kiwifruit seed oil microcapsule which made by "air stream tiny hole"and spray dry method were systematically researched. The physicochemical property, storage stability and release property of kiwifruit seed oil microcapsules were also covered. The main results of this study were as follows: 1. Pressure is the major factor affecting the solubility of kiwifruit seed oil in supercritical CO2. The transforming pressure for extracting kiwifruit seed oil by supercritical CO2 extraction is approximately 27.8Mpa. When the pressure is less than this value, solubility will decrease as temperature rising, therefore, a lower extraction temperature above supercritical point should be adopted to achieve a higher solubility; while the pressure is more than 27.8Mpa, solubility will increase with the temperature rising; with the condition of 30MPa and 35MPa, extraction temperature rise to 45℃from 40℃, solubility of kiwifruit seed oil in supercritical CO2 will not increase significantly. Thus, the suitable extraction conditions are pressure 30~35 MPa, temperature 40℃; Water contents will affect solubility of kiwifruit seed oil, water content of materials should neither too high nor too low. 5~7% of water content should be maintained when the kiwifruit seed oil is extracted by supercritical CO2. Solubility of fatty acids ethyl esters of kiwifruit seed oil in supercritical CO2 are significantly different in the test conditions. Different fatty acids ethyl esters of kiwifruit seed oil can be separated by varying temperature and pressure. 2. Temperature, pressure, CO2 flow have a great impact on fractionation effectiveness of kiwifruit seed oil by supercritical CO2. Single factor experimental result indicates that, when fatty acids of kiwifruit seed oil are separated by supercritical CO2 extractive distillation, the optimum conditions are that fractionation column operating on temperature gradients of 40-55-70-85, pressure 15MPa, CO2 flow rate 3000g/h, and extracting pressure 20MPa, extracting temperature 35℃. Under this operation condition content of a-linolenic acid in the kiwifruit seed oil will reach 69.91% after fractionation. Content of a-linolenic acid in kiwifruit seed oil will reach 73.53% by increasing pressure in accordance with procedure. The combination of urine inclusion and Ag+ complex with supercritical CO2 fractionation can respectively increase linolenic acid content of kiwifruit seed oil to 72.30~75.99% from the 69.91% of single fractionation. A preliminary research on technology of continuous concentration kiwifruit seed oil a-linolenic acid by supercritical CO2 fractionation was produced. At oil feed flow rate 3.3~5.1g/min, CO2 flow rate 3000g/h, column pressure 15MPa, a-linolenic acid of kiwifruit seed oil can be increased to 75.35~75.18%. 3. The optimum condition of molecular distillation separation on kiwifruit seed oil are temperature 110℃, pressure 3.5Pa, and oil feed flow rate 30~40 drops/min, rotational speed of membrane stripper 400r/min, feed temperature 55℃. Single step molecular distillation increased the level of a-linolenic acid in kiwifruit seed oil from 61.82% to70%. The most suitable separations conditions of multistsge operation method are distillation temp 90~120℃, pressure 3.0~4.0Pa, oil feed flow rate 30 drops/min, rotational speed of membrane stripper 400r/min, feed temp 55℃. The concentration of a-linolenic acid in kiwifruit seed oil can be increased to 84.33% from the previous 67.5% by 4 steps molecular distillation. 4. This study aims to develop higher content of a-linolenic produce with kiwifruit seed oil, provides a new direction of healthy products. The study shows that the best conditions of urea inclusion technology enrichment a-linolenic acid are mass ratio of fatty acid, urine, 95% of alcohol is 1:3:7, temperature –15℃, inclusion time 15h. Under these conditions, a-linolenic contents can reach 87.2%. Using urine inclusion to enrich a-linolenic acid in kiwifruit seed oil is a method of mild temper, simple, low cost; it is an effective way for preparation of high content a-linolenic acid of kiwifruit oil. 5. When spray dry method is used to prepare kiwifruit seed oil microcapsules, proper wall material combination is soybean protein isolate and maltodextrin. The best emulsion formula for spray dry kiwifruit seed oil: soybean separated albumen/maltodextrin is 1:1, core/wall is 1:1.5, concentration of emulsion is 25%. The optimum technological condition on spray dry method is: entering air temperature 180℃, homogening pressure 30 MPa, air outlet temperature 82℃; On this condition, kiwifruit seed oil encapsulation efficiency can get 85~90% and it has better test reproducibility. 6. The formulation for preparation of kiwifruit seed oil microcapsule using "air stream tiny hole"is sodium alginate concentration 2.5%, the best proportion of wall material, sodium alginate, and core material, kiwifruit seed oil, is 1:1, emulsifying agent is 0.2% tween80+0.1%stearin, CaCl2 concentration is 2.0%.The proper spray dry technical parameters are material flow speed 20 ml/min, spray air pressure 0.05MPa, spray distance 40cm.Encapsulation efficiency of kiwifruit seed oil is up to 93.05% in this condition. It becomes possible to industrialization production of microcapsules by the means of "air stream tiny hole"microencapsulation. 7. The quality of kiwifruit seed oil microcapsules made by "air stream tiny hole"and spray dry method accords with that of quality requirement of ordinary microcapsules; kiwifruit seed oil microcapsules prepared by these two methods have different size distribution and different solubility and have extensive uses; during storage, oxidizing speed of kiwifruit seed oil that microencapsulated is obviously lower than that without microencapsulated. During storage kiwifruit seed oil content declines slowly, and core material preservation is higher. Microencapsulation can prevent kiwifruit seed oil from volatilizing, reduce oxidizing speed rate, thus to prolong the preservation period of kiwifruit seed oil. 8. Kiwifruit seed oil microcapsules release slowly in man-made gastric juice and release fast in man-made intestinal juice, hence it has a good controlled release and enteric solubility, it is conforms with the requirements of ordinary microcapsules products on control release; kiwifruit seed oil microcapsules prepared by different method has different properties, and it can meet the needs of different control release; kiwifruit seed oil microcapsule's release speed rate follows First Order Reaction Dynamic Model, namely, release speed rate is in direct proportion to microcapsules core surplus mass, linear equation. The bigger the particle is, the smaller the constant of release speed rate is.
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