【作者】 徐抗震；

【导师】 宋纪蓉；

【作者基本信息】 西北大学 ， 化学工程， 2005， 博士

【摘要】 本文以当前亟需解决的陕西省二十多条苹果榨汁生产线排放的60多万吨苹果渣为主要原料,采用生物技术发酵生产饲料蛋白,解决困扰苹果榨汁企业发展的难题,充分利用资源,减少环境污染,同时为短缺的蛋白饲料来源开辟一条新途径。并以此进行相关的发酵技术研究,完善发酵理论,为其他果渣、酒糟及纤维素秸秆的研究开发提供借鉴。 利用自行设计的激光辐射诱变方案,获得了适合苹果渣发酵生产饲料蛋白的更优菌株,并通过实验得到了多菌种的最佳接种混合比。同时,确定了鲜苹果渣的较佳干燥方式,为工业规模化处理提供保障。通过单因素实验和正交实验研究了氮源的添加形式和较佳固态发酵培养基的组成,并分析和讨论了发酵过程的浓缩效应与功效评价。 在获得单独固态发酵适宜生产工艺条件的基础上,提出了液固态发酵和固固态发酵两种新的发酵工艺流程,通过对三种工艺形式的技术和经济可行分析,发现液固态发酵混合菌种共生与协同作用能力强、生长快,相对接种量大,发酵时间短,设备利用率高,且蛋白含量高,适合现代工业化规模生产。而固固态发酵生产工艺相对简单,且投资与生产费用低,更有利于推广应用,彻底解决苹果渣的处理难题。 通过元素分析、灰分测定和燃烧热测定,计算出假设为纯物质的发酵原料与产物的宏观分子式和生成焓,进而推导出发酵过程的计量学方程式和总的热效应。同时,利用数学软件对实验数据进行最优化拟合,获得了发酵过程的数学模型和动力学方程。根据得到的动力学方程和其导函数以及对应的极值和时间,分析了发酵过程的内部变化规律,确定了发酵过程,比较并优化了工艺过程和发酵参数。将红外光谱分析技术应用于发酵原料和产物的研究,解释了特征吸收峰和主要成分之间的变化规律,为建立红外技术监测固态发酵过程的方法奠定基础。 提出了符合可持续发展的苹果资源综合开发的绿色循环过程,并对下一步主要工作做了初步设想和构思,完成课题组提出的苹果资源综合开发技术战略,使陕西的苹果资源走上绿色循环发展之路。更多还原

【Abstract】 Apple pomace, the residue left from juice extraction, is about 25% of fresh apple weight. Approximately several million tons of apple pomace are produced annually in China, more than 0.6 million tons in Shaanxi province which is the biggest apple production base. Because of the high proportion of organic acids and very little protein (about 6% in dried apple pomace), apple pomace cannot be used as feedstuff directly. At present, almost all of apple pomace is discarded. When fermented by natural microorganism, it emits bad niff and causes a serious environmental problem. This restricts the development of apple juice production. Using biotechnology and fermenting apple pomace for feeding protein is a practical way. It not only offers protein for livestock breeding, but also helps solve pollution problems. At the same time, interrelated technology of solid-state fennentation (SSF) was studied in this paper, it will perfect the theory of fermentation, and help develop other pomaces, lees and straws.Using laser radiation equipment made by us, better strains for producing feeding protein from apple pomace and their optimal mixed proportion of inoculation were obtained. Preferable method for fresh apple pomace drying was confirmed, which would offer assurance for industrial treatments. Through single factor experiments and orthogonal experiments, nitrogen source and optimal substrate were studied, and concentrated effect and efficacy evaluation of nitrogen source were analyzed in the process of fermentation.Based on the optimized technological conditions of single solid-state fermentation (SSF), two new fermentations, liquid-solid-state fennentation (LSSF) and solid-solid-state fermentation (SSSF), were introduced in this paper. After technical and economical analysis on these three fermentation technologies, the results indicate that mixed strains have strong intergrowth and synergistic capabilityand grow quickly in the process of liquid-solid-state fermentation (LSSF). Moreover inoculum’s concentration is big, fermentation time is short, utilization ratio of equipments and protein content in products are all high, and it is very good for the modern industrial production. But solid-solid-state fermentation (SSSF) is the most simple and needs lower cost of investment and production, it is very convenient to be applied widely, and solves the problem of apple pomace.Through elements analysis and determination of ash and combustion heat, molecular formulas and formation enthalpies of materials and products, which are all considered as pure substances, were figured out, and then metrology equation and total thermodynamic effect of the whole fermentation process were gained. Subsequently, according to the results of optimum fitting to experimental data, mathematic model and kinetic equation were obtained. Using the above kinetic equation and its differential coefficient, different extremum and corresponding times were deduced to analyze the inner change law of the fermentation process and optimize the technological parameters. FTIR was used in this work to study materials and products of the fermentation, after explained relationship between characteristic absorption peak and component change, a method, using IR to scout and observe the fermentation process, will be established in the future work.At last, green cyclic process of apple resource was introduced in this paper, which met the needs of continuable development. The further work was considered and designed to complete the cyclic process, and made the Shaanxi apple resource towards the way to green cyclic development.更多还原