| Alginate is a natural polysaccharide extracted from brown algae plants, is an abundant and environmentally friendly living marine resources. With the development of materials science and bio-medicine, more and more scholars began to study the alginate, its application prospects.In this paper, sodium alginate as film-forming agent, calcium ions as crosslinking agent, by solvent evaporation method, the preparation of calcium alginate film, and then in the alginate system has added chitosan, dextrin prepared by blending modified composite film. Studies based on calcium alginate and calcium alginate film blends modified composite membrane permeability studies, permeability factors alginate composite films and blends modified impact study, carried out the following tasks:1. Preparation and characterization of thin films and blends modified alginate composite membrane research. Alginate, calcium chloride, chitosan, dextrin was prepared from alginate and composite film. FTIR results show that, in the system after adding calcium alginate chitosan, displacement characteristic absorption peaks occurred, and then on the basis added dextrin in alginate-chitosan film that the complex film IR was no significant change, indicating the added dextrin not happen with alginate and chitosan chemical reaction. SEM analysis of the scan results by comparing calcium alginate, calcium alginate- chitosan, alginate- chitosan- dextrin film surface and cross section, found the addition of chitosan and dextrin were changed alginate calcium film structure, make it more compact.2. The influence of water vapor permeability of calcium alginate film and composite membranes were studied. The results show that the impact of calcium alginate films WVP is the largest cross-linked sodium alginate, calcium ion concentration, followed by cross-linking time. By experimentally derived the concentration of alginate is no effect for WVP of alginate film system, the best condition of alginate film is Calcium crosslinking time 20 min, calcium ion concentration is 50 g / L. Water vapor transmission rate of Alginate film is 8.0244 × 10-6 g /(m ? h ? Pa) under optimal craft. On this basis, adding chitosan, alginate to make it happen with polyelectrolyte react to form calcium alginate- chitosan blend films. Chitosan concentration range from 0 to 1 percent inspection, when the concentration of 0.75% WVP than pure alginate films decreased by 10%, in order to further increase the density of the film, reducing the WVP, in alginate- chitosan composite film of small molecules dextrin added as a filler to prepare alginate-chitosan- dextrin composite film. In alginate- chitosan- dextrin white dextrin concentration composite film from 0 to 2 percent range trips, white dextrin concentration of 2%, WVP decreased 7.4%.3. Use Valia-Chien diffusion cell research alginate and modified the four flavoring substances composite membrane permeability, and with static headspace-gas chromatography-mass spectrometry method used in conjunction with quantitative detection of n-propanol, ethyl acetate, n-butyl alcohol, ethyl butyrate concentrations of the four flavoring substances, were investigated alginate-chitosan, alginate-chitosan-maltodextrin blend modified composite film consisting of permeation rates of the four flavoring substances affected. In alginate-chitosan composite film, there are factors that need to examine the concentration of chitosan, with increasing concentrations of water-soluble chitosan, n-propanol, ethyl acetate, n-butanol, ethyl butyrate in composite membrane permeation rate smaller, added in an amount 0.75%, four kinds of flavor compounds n-propanol, ethyl acetate, n-butanol, acetic acid ester alginate film diffusion coefficient decreased by 26.85%, 42.92%, 21.22%, 75.9%. In alginate/chitosan system basis, adding maltodextrin, when added maltodextrin amount to 2%, the composite film four flavoring substances n-propanol, ethyl acetate, n-butanol, ethyl butyrate diffusion coefficient was reduced 15%, 19.38%, 16.78 %, 14.4% to compare with alginate-chitosan.3. For Alginate / chitosan / dextrin composite film, in addition to the distribution ratio Expedition, also investigated other factors that affect its flavor compounds diffusion coefficient: permeate matrix liquid kind dextrin, chitosan deacetylation degree, addition of calcium ion receptor fluid; test ODO configuration permeate oil solution of the same concentration of fragrance material as permeate, contrast the same concentration, the water permeate as a matrix configuration as a matrix configuration and oil permeate diffusion coefficients of aroma compounds, the result, the diffusion coefficient of n-propanol is not much affected, and ethyl acetate, n-butyl alcohol, ethyl butyrate diffusion coefficient was reduced by 70%, 25%, 73%. Different types of dextrin replace maltodextrin inspect, select β- cyclodextrin, white dextrin comparison showed that β- cyclodextrin added to the diffusion coefficients of aroma compounds aroma better than maltodextrin and White dextrin, ethyl acetate, n-butanol, ethyl butyrate diffusion coefficient decreased by 58.14%, 45.5%, 21.5%... |
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