【作者】 唐飞；

【导师】 余挺；

【作者基本信息】 浙江大学 ， 食品工程， 2012， 硕士

【摘要】 由本实验室分离出的海洋酵母红冬孢Rhodosporidium paludigenum Fell & Tallman,经研究发现该菌对多种果蔬如苹果、梨、冬枣、番茄等采后病害均具有良好的抑制效果,是一种新型的生防拮抗菌。高活性干酵母粉剂的制备是实现酵母拮抗菌生防产品商品化生产的关键技术之一。本文主要研究了制备R.paludigenum活性干粉的方法并对其喷雾干燥工艺进行了优化,同时验证了喷雾干燥所得酵母活性干粉的生防效果。本论文主要研究成果如下：1.设计了喷雾干燥制备R. paludigenum的工艺流程,包括酵母的活化、种子培养、发酵培养、发酵液预处理、酵母干燥以及干粉的收集和储藏方法。2.探究了热激温度和时间、培养基氯化钠浓度、喷雾干燥进口温度和进料速率、喷干保护剂的种类和浓度对R. paludigenum细胞存活力的影响,利用正交试验进行了喷雾干燥工艺的优化。得到较佳的喷干条件为：热激温度39℃；热激时间5 min；保护剂为20%的脱脂乳；培养基氯化钠浓度0.5%。3.选择苹果和梨,研究了复水处理对海洋酵母R. paludigenum喷干粉生防效力的影响。结果表明干粉无菌水悬浮液离心后,再用无菌水或者生理盐水悬浮所得悬浮液的生防效力较好。4.测定了常温和冷藏温度对海洋酵母R. paludigenum冻干粉活性的影响。结果显示冷藏温度更有利于干粉活性的保持,储藏3个月后,活菌数虽有所下降,但仍然可以用于水果防腐保鲜。更多还原

【Abstract】 The marine yeast Rhodosporidium paludigenum Fell & Tallman was separated by our laboratory. Previous study found that it was new biocontrol antagonist yeast and had good inhibitory effect on a variety of fruits and vegetables such as apples, pears, winter jujubes and tomatoes. The preparation of dry yeast with high activity is one of the key technologies in its commercialization. The paper mainly investigated the preparation method and the optimized the spray drying process of R. paludigenum. Then the biocontrol effect of yeast powder prepared by spray drying was proved. The main research results were as follows.1. The spray drying process of R. paludigenum was given, including the yeast activation, seed cultivation, fermentation cultivation, pretreatment of fermentation liquid, spray drying and collection of yeast powder.2. The factors such as heat shock temperature and time, salt concentration of culture medium, import temperature of spray drying, feed rate and protectants concentration whose effect on cell survival of R. paludigenum was researched. Orthogonal test was used to optimize spray drying process. The best spray drying conditions was as follows:heat shock temperature was 39℃, heat shock time was 5 minutes, skim milk concentration was 20% and salt concentration of culture medium was 0.5%.3. Rehydration method’s influence on the biocontrol effect of R. paludigenum in apples and pears was investigated. The results showed that the yeast powder suspension with sterile water was centrifuged then resuspended by sterile water or sterile saline water. The suspension has good biocontrol effect.4. Two storage temperatures’ effect on activity of freeze-dried R. paludigenum was studied. The results showed that cold storage was suitable to store active dry yeast. Stored at 4℃for 3 months, the yeast could be used for restraining the decay of fruits, although the living cells dropt a litter.更多还原