【作者】 千梅；

【导师】 陈从贵；

【作者基本信息】 合肥工业大学 ， 农产品加工及贮藏工程， 2007， 硕士

【摘要】 冰核活性蛋白是冰核活性细菌或冰核活性真菌合成的一类蛋白质，其显著特点是可以提高成冰核温度和降低水的过冷却点。本研究主要利用冰核活性蛋白可以提高水溶液的成冰核温度的性质，将其应用于食品冷冻工业。通过对冰核活性蛋白的制备及其热特性的研究，以期找到一种可降低冷冻食品生产能耗的冰核蛋白，提高生产效率、促进食品冷冻工业的发展。采用单因素实验和正交实验寻找冰核活性细菌(野油菜黄单孢菌)和真菌(禾谷镰刀菌)的发酵培养条件，研究禾谷镰刀菌冰核活性蛋白的分离方法，同时考察所制冰核活性蛋白对蛋清蛋白冰点的影响。结果表明，适于野油菜黄单孢菌发酵的条件为：装液量40ml、接种量3％、初始pH8.0，在此条件下获得的野油菜黄单孢菌的总活性为30.73；适于禾谷镰刀菌发酵的条件为：装液量30ml、接种量3％、初始pH6.0，在此条件下获得的禾谷镰刀菌的总活性为493.46；对于禾谷镰刀菌发酵生产冰核活性蛋白的分离，25％的乙醇沉淀冰核活性蛋白的冰核活性比原菌液提高了220％；利用差示扫描量热法对禾谷镰刀菌冰核蛋白的热特性进行了研究，结果表明加入禾谷镰刀菌和野油菜黄单孢菌都对蛋清液的冰点有提高，并以禾谷镰刀菌的效果更佳。更多还原

【Abstract】 The ice nucleation-active protein is a kind of protein that was produced by the ice nucleation-active bacteria. Such protein allows the freezing of water droplets at higher temperatures and lower the super cooled temperature. It is significative that of studying on the culture, seperation and the thermal property of the ice nucleation-active protein, using the ice-nucleating active protein on the food freezing industry. It could reduce the producing-cost , improve the producing-efficiency, ensure the quality of the production, promote the development of the food freezing industry.In this paper, the ice nucleation activity and the biomass of ice nucleation-active bacteria (Xanthomonas campestris and Fusarium graminearum) was studied by the orthogonal experiment. Also, the purification of ice nucleation-active protein from Fusarium graminearum was studied. Then, the influence of ice nucleation-active protein on the freezing point of egg white protein was saw about.The best ferment condition of Xanthomonas campestris was that: 40 ml of the fermented broth, 3% of the seed volume, pH 8.0, the whole ice nucleation activity is 30.73. The best ferment condition of Fusarium graminearum was that: 30 ml of the fermented broth, 3% of the seed volume, pH 6.0, the whole ice nucleation activity is 493.46.The ice nucleation activity of Fusarium graminearum is stronger than that of Xanthomonas campestris.The result of seperation is best using 25% ethanol.The result of DSC shows that both Xanthomonas campestris and Fusarium graminearum can increase the freezing point of egg white protein.更多还原