| β-poly malic acid (PMA) is a new type of polymeric biomaterials, due to its small molecular weight in terms of application is restricted in chemical synthesis, biosynthetic preparation of β-poly malic acid, a high molecular polymer, becomes the current research hots pot. The issue is that according to the use of Aureobasidium pullulans fermentation getting the fermentation conditions optimize in the original on the basis to improve the β-poly malic acid production. Through single factor experiments and response surface design, carbon source, nitrogen source, such as calcium carbonate were optimized. The optimal fermentation conditions were:120g/L glucose, ammonium succinate calcium carbonate3.02g/L,29.69g/L, pH4.69, and β-poly malic acid production reached18.25g/L, the relative to the optimal production was increased by88.3%.With chitosan(CS) and P-poly malic acid as the wall materials, we chose complex condensed to make essence microcapsule through the Plackett-Burman (PB) experimentals and related factors in the evaluation, screening the remarkable effect factors, that are significant factors for the concentration of chitosan, the emulsifying time, the rotational speed, the reaction time. Through response surface designs, the optimized preparation of sustained-release fragrance conditions were:the concentration of chitosan1.5g/L, the emulsifying time45min, the rotational speed600r/min, the reaction time30min, the concentration of β-poly malic acid was1.0g/L, β-poly malic acid (mL):chitosan (mL)=1:2, the pH value of chitosan6, the dropping speed7.5mL/h, the core material1mL, by SEM observation and wall material forming microsphere microcapsule, it was481.0nm, the embedding rate was28.57%and the sustained release was lasting.This paper studied complex coacervation for microcapsule with P-poly malic acid and chitosan as wall materials and Nifedipine for the capsule core. Using Plackett-Burman designs for complex coacervation system formation conditions of preliminary screening, on this basis, using the response surface designs in-depth study on the impact of the microcapsule particle size and dispersion coefficients of various factors to obtain suitable preparation conditions, the concentration of β-poly malic acid was1.0g/L, the concentration of chitosan was0.5g/L, P-poly malic acid and chitosan solution volume ratio was2:1, the pH value of chitosan was4, the concentration of Nifedipine solution was1.0g/L, nifedipine added to3.0mL, β-poly malic acid solution dropping acceleration was5.0mL/h, the stirring speed is600r/min, the reaction time was45min, the microcapsules of average particle diameter was525.6nm and the average dispersion coefficient was0.186, the embedding rate reached43%.β-poly malic acid and gelatin were as two wall materials in the topic. The hollow microcapsules were preparated by complex coacervation method to get the uniform particle size, dispersion (PdI) smaller microcapsules conditions. On the basis of the preliminary experiments, according to the Plackett-Burman experimental designs, the concentration of PMA, the pH value of gelatin, the concentration of gelatin, dropping speed, rotational speed and reaction time six factors were Investigated on the microcapsule particle size and PdI influence, and obtained that the dropping speed and rotational speed influenced the particle size and gelatin concentration had significant effect on PdI. On the basis of the Plackett-Burman(PB) experiments to establish the Box-Behnken design, using response surface design analysis method to get a small particle size and Pdl microcapsule. With diameter and PdI as response values, we Investigated the effects of PMA concentration, the concentration of gelatin, the pH value of gelatin and the reaction time and the interaction between them on the impact response value. The optimum conditions were:the concentration of PMA0.14%, the of gelatin0.16%, the pH value of gelatin4.11, the reaction time38.69min. The best microcapsule can be obtained for275.73nm,0.309for PdI. |
PDF Full Text Request