【作者】 那宇；

【导师】 苏平；

【作者基本信息】 浙江大学 ， 食品安全， 2007， 硕士

【摘要】 超高压技术应用于食品加工在国际上已有十多年的历史，超高压处理技术比热处理更好的保持了食品的原有风味、色泽和营养价值。榨菜是我国主要的腌渍蔬菜和世界三大酱腌菜之一，一直深受广大消费者的青睐。软包装榨菜是市场上主要的流通形式，但是一直受胖袋和防腐剂问题所困扰。关于超高压杀菌技术在我国传统的腌渍品中还很少，本文研究超高压技术对软包装榨菜杀菌效果的影响，主要研究结果如下：1．研究了超高压技术处理软包装榨菜的杀菌效果的影响，进行了3组单因素实验和一组正交实验。得到超高压杀菌的最佳工艺为压力300 MPa，保压20 min，能有效地防止胖袋。2．比较超高压处理、热处理以及添加防腐剂的超高压处理和热处理对榨菜的品质和胖袋情况的影响。超高压处理感官上好于热处理，热处理有蒸煮味。榨菜的脆度随着时间的延长呈下降趋势，Ck组下降最为显著，添加防腐剂组、加热加压组可以更好的保榨菜的脆度(P＜0.05)。榨菜中的蛋白质含量处理后都有所升高，经过高压处理组增加显著，达10％左右，氨基酸的含量有所增加，但加热组、加压组间差异不显著。亚硝酸盐有不同程度的降低，加热处理更有利于榨菜中亚硝酸盐的降解。3．研究了超高压和加热协同处理的工艺。当杀菌温度为70℃，加热7 min，超高压在200 MPa下保压20 min可以取得最好的杀菌效果，且杀菌温度和超高压压力在95％的显著水平上对杀菌效果具有显著性影响。4．研究了造成软包装榨菜胖袋的原因-微生物。从软包装榨菜中分离得到8株细菌，2株霉菌，2株酵母。利用反证法找到使软包装榨菜产气的微生物—2株酵母菌。研究其耐温和耐压性，其中酵母A对温度敏感，加热很容易将其杀死，但较耐压；酵母B对压力敏感，300 MPa的压力即可防止胖袋，但较耐热。因此本文认为采用加热和加热的协同效应杀菌可以更经济的控制榨菜的胖袋。更多还原

【Abstract】 Ultra high pressure technology has been used in the food industry for a couple of years. The quality of high pressure sterilized products is usually superior to conventionally heat sterilized products, this applies particularly to texture, colour, flavour and retention of nutrients. Mustard Tuber is our nation’s mainly pickled vegetables and one of three pickled vegetables in the world. Packaging pickled mustard tuber has become the popular form in the market, however, is always harassed by the problem of bag inflation. There is little paper that studied the application of ultra high pressure sterilization on pickled vegetables. Effects of ultra high sterilization on packaging pickled mustard tubers were studied, and these are results:1. Effects of ultra high pressure treatments on the microflora of packaging pickled mustard tubers were studied. Three groups of single-facktor experiments and a group of orthogonal experiments were carried on. We found that the best sterilization processes is high pressure treatment at 300 MPa for 20 min that can effectively prevent inflation.2. Six groups of treatment including control group, high pressure process, heat process, high pressure process and heat process with preservatives, pressure process with heat process beforehand on packaging pickled mustard tubers were studied. Mustard tuber treated with pressure has a better sensory evaluation, and the heat group affected flavour. Brittleness of mustard tuber decreased with the prolonging of shelf time, the control group was the worst, the group with preservatives and pressure process with heat process beforehand were nearly not affected(P<0.05). Protein content increased after being treated, the group treated with high pressure has the most marked effect, increased as much as 10%. Amino acid contents of mustard tuber increased after being treated, no significant effect was discovered within the high pressure group and heat group. Heat process decreased the content of nitrite in a significant way.3. Synergistic effect of heat and pressure treatment was studied. The best sterilization process was heated at 70℃for 7 min, then treated at 200 MPa for 20 min. Analysis of variance found that sterilization temperature and pressure significantly affected the results (P<0.05).4. The microbial reason for inflation was studied. Eight bacillises, two yeasts and two molds were isolated from packaging mustard tubers. It showed that two yeasts were the reason for inflation bags in counterevidence experiments. Yeast A was found be alert to temperature, but be tolerant to pressure, and Yeast B had just reversed results. Synergistic effect of heat and pressure was considered to be controlling inflation from happening the most effective and economical way.更多还原