【作者】 陈建新；

【导师】 徐岩；

【作者基本信息】 江南大学 ， 发酵工程， 2014， 博士

【摘要】 目前，我国黄酒的年产量约150万吨，发展非常迅速，与此同时，黄酒产业也存在污染及能耗大，装备水平及自动化程度不高等发展“瓶颈”。亟需进行系统深入的研究，提升黄酒生产过程的技术及装备水平，实现黄酒产业现代化，使黄酒产业在保持传统特色的基础上走上可持续发展的道路。在黄酒酿造过程中，蒸煮操作是污染物排放及能源消耗最大的工序，包括大米的浸泡和蒸饭两个操作步骤。浸泡操作每年产生90万吨高浓有机废水，其中含2.7万吨COD污染物。蒸饭操作年蒸汽消耗约为48万吨，折合标煤6.48万吨。不需要浸泡操作的焙炒技术属于粮食淀粉干法糊化技术，可以革除大米蒸煮糊化操作的浸泡废水，大幅度降低黄酒酿造过程的废水排放量和污染物排放量。但是，当前大米焙炒技术还存在许多问题，主要包括：焙炒尾气排放造成大气污染和能源浪费；焙炒设备加工精密度要求高，设备投资大，控制精度也有较高要求，维护保养困难等；对焙炒技术的研究也存在研究水平低，缺乏对焙炒过程粮食淀粉糊化变化模式和机制的清晰认识，缺乏明确直接指导焙炒过程控制和设备放大的理论基础和方法。过热蒸汽焙炒可以克服空气焙炒时尾气排放造成的大气污染和能源浪费，实现酒类的“绿色”酿造。为此，进行过热蒸汽焙炒技术的系统研究，最终得出结论如下：(1)根据传热能力高的稀相流化床和浅层流化床的原理及大米流化特性优化设计实验流化床，并优化得到实验流化床的最佳传热操作条件即进料量为10g，气体流速为1.5倍起始流化速度，即4m s-1。在这种条件下，实验流化床的焙炒传热速率最高。在最佳传热条件下进行了焙炒大米工艺参数的优化和水化性质及膨胀率比较分析，发现过热蒸汽200oC时，在30～50s的时间范围内大米的糊化率基本相同，并且无明显的副反应，保证了大米在连续操作条件下有一定的停留时间分布，被确定为实验大米焙炒的最佳工艺参数。采用不同加热介质焙炒大米的比较研究发现，加热介质对焙炒糊化效果影响不大，过热蒸汽与空气焙炒大米的糊化率基本相同，过热蒸汽略高。(2)根据对焙炒过程中大米细微结构、糊化性质和结晶等的变化分析，发现在最佳操作条件下，焙炒过程存在两个明显不同的阶段，升温阶段和膨化阶段，其中升温阶段又可以分为两个时期：准备期和快速糊化期。在升温阶段，大米快速升温，内部的分子结构和特性急剧变化，但宏观并不大。膨化阶段，大米升温速度显著下降，但由于温度已经超过大米的熔点，发生了膨化现象，大米的体积和宏观结构变化发生了巨大的变化。两个阶段的分界点在20～25s之间。由于两个阶段的显著差异，在焙炒控制上也需要采用不同的控制方式。利用模拟实验装置的数学模型分析焙炒过程中大米内部温度分布变化，确定了焙炒过程中大米温度变化的最佳模式，提出了焙炒过程的标准温度控制曲线。由此提出焙炒过程设计和放大策略：根据焙炒过程温度变化特征控制焙炒过程中大米的温度变化，大米平均温度变化应符合标准温度控制曲线。(3)采用部分数值模拟法构建了过热蒸汽焙炒大米活塞流流化床的数学模型。根据焙炒初期蒸汽冷凝及再蒸发的特征，采用第一类边界条件下偏微分方程模拟了这一过程，并以分段函数的形式表达了整个过热蒸汽的焙炒过程。利用活塞流流化床模型分析了工业过程焙炒流化床的结构和操作参数对焙炒过程的影响，针对工业过程的要求提出了两段焙炒流程。通过两段焙炒模型分析发现在两段焙炒系统中大米平均温度曲线与标准温度控制曲线很接近，处理能力远高于实验装置，常规的活塞流型流化床可以用于两段焙炒大米。利用工业模型对两段焙炒过程进行优化，得出两段大米焙炒时，处理能力为实验条件下处理能力的7～8倍，即12.88～14.72kg (s m-2)。加热段的操作条件是过热蒸汽温度270～280oC，停留时间12.5s，过热蒸汽的空床速度4m s-1。保温段的过热蒸汽温度200oC，停留时间27.5s，过热蒸汽空床速度3m s-1。综合取得的优化参数，确定了工业化焙炒工艺设计和系统设计步骤，为实施黄酒“绿色”中试和产业化提供了完整的节能减排解决方案。(4)采用蛋白质溶解度分析法，研究了焙炒过程蛋白质热变性现象，发现大米蛋白的热变性发生在焙炒前期，并且变性程度较深，但焙炒大米的蛋白质变性程度低于传统的浸泡蒸煮大米，粳米与糯米的变性过程和程度基本相同，使用不同的加热介质对大米蛋白的变性没有显著影响。通过测定大米中油脂含量在在焙炒过程中的变化，发现焙炒大米中游离油脂的挥发量较大而结合油脂的挥发量较小。粳米油脂难挥发而糯米油脂容易挥发。比较研究了不同加料方式对黄酒发酵的影响，初步认定补料发酵法是适合焙炒大米酿酒黄酒的工艺。通过理化指标检测、感官分析和风味物质分析，认为使用焙炒大米可以酿造出与传统黄酒相同风味的黄酒，但与传统酿造的黄酒相比，在感官品评上还存在微小的差距，主要原因是焙炒米黄酒的风味物质含量略低。认定以过热蒸汽为介质焙炒大米的方法可以用于黄酒生产，但需要对焙炒大米酿酒黄酒技术进行更深入的研究和优化。更多还原

【Abstract】 At present, the annual output of Chinese rice wine is1.5million tons with a rapid rate ofdevelopment. Meanwhile, the development of the Chinese rice wine industry has encounteredsome bottlenecks, such as low level of processing technology and production efficiency, highpollution and excessive energy consumption, and the low degree of Equipment level andautomation. The further system research is necessary to enhance the level of productiontechnology and equipment in order to achieve a modern Chinese rice wine industry, resultingin a path of sustainable development based on the traditional characteristics.During rice wine production process, the production units of soaking and rice cooking arethe main source of pollutants and high energy consuming.0.9million tons of waste water withhigh concentrated organic waste, containing27thousand tons of COD pollutants, are generatedannually in the soaking phase. Meanwhile, it takes0.48million tons of vapor for rice cookingevery year, converting into64.8thousand tons of standard coal. The roasting technique withoutsoak water, significantly reduces emissions of waste water and other pollutants. However, thistechnique causes several extra problems, such as exhaust gas pollution by roasting, highprecision and investment requirement on roasting equipment, a large cost on control andmaintenance. In addition, study on roasting technique and substance variation is not in depth,causing the lack of theoretical basis guidelines on roasting process control and equipmentamplification.A new technique, called superheated steam roasting, could overcome the air pollution andenergy waste during roasting, and thus implement "green" brewing of Chinese rice wine.Therefore, the systematic study focused on the Chinese rice wine brewing with superheatedsteam rice roasting process. The main results are concluded as follows:(1) The experimental fluidized device is designed according to the fluidizationcharacteristic of rice based on the theories of dilute phase fluidized bed and shallowfluidized bed with high capacity of heat transfer. And the operating parameters areoptimized to achieve the optimal heat transfer rate of roast: input amount of10g,fluidized gas velocity of4m s-1which is1.5times higher than initial velocity. In thecase of optimal heat transfer, the technological parameters of roasting are optimized andthe hydration property and expansion rate is compared. The results showed that theexpansion rate of rice had no significant differences during the30~50seconds ofroasting time at superheated steam200oC without occurrence of secondary reactions.The above technological parameters are considered to be the optimal condition for riceroasting since certain retention time is available during the continuous operation.Comparative study of the different heating medium roast rice find gelatinization rate ofsuperheated steam rice and air roasted rice is similar and gelatinization rate ofsuperheated steam rice superheated steam is slightly higher.(2) Analysis of change information of rice microstructure, properties and crystallineduring roasting process, that under the optimal operation condition, roasting processcan be divided into two stages, heating and puffing. The heating stage can be divided into the two period: preparation period and rapid gelatinization period. The sharp risein the temperature of rice during heating stage, molecular structure and characteristicof internal change sharply. The heating rate significantly decreased during puffing,but rice begins puffing due to the temperature over the melting point of it. Greatchanges have taken place in the volume and the macro structural changes of rice. Thedividing point of the two stages is between20~25seconds. Changes in the riceinternal temperature distribution during roasting process have been analyzed using theexperimental model, so the best mode roasted rice temperature changes duringroasting is determined, the standard temperature control curve for roasting is proposed.The roasting process design and amplifying strategy is proposed: According to thetemperature change characteristics of roastcheng process control temperaturevariation of rice. Change of rice average temperature should conform to the standardtemperature control curve.(3) By using the method of numerical simulation, industrial process models of continuousrice roasting using superheated steam were constructed respectively. Roasted rice usingsuperheated steam model contains the initial steam condensation simulations.Influence of the structure of fluidized bed and operating parameters on the roastingprocess were analyzed using a section roasting process model. According to therequirement of industrial process, two sections roasting technology has been proposed.The roasting model analysis found that the average temperature curve of rice in the twosections roasting system is close to the standard temperature control curve. Productioncapacity is far higher than the capacity of the experimental device. The ordinary plugflow fluidized bed can be used for two sections roasting. The optimization results showthat processing ability of the two sections roasting system is7~8times the processingability of experiment equipment, that is12.88~14.72kg (s-1m-2). The heating sectionoperating conditions are the superheated steam temperature of270~280℃, residencetime of12.5s, the superheated steam empty bed velocity4m s-1. Insulation section ofsuperheated steam temperature of200℃, residence time of27.5s, superheated steamempty bed velocity3m s-1.Industrial roasting system design and process design procedures have beenproposed. Complete program is provided for the implementation of pilot andindustrialization.(4) The thermal denaturation of rice protein occurred in the roasting stage is studied byprotein solubility analysis. It is found that the thermal denaturation of rice proteinoccurred in the early roasting stage, and a greater degree of degeneration. But roastedrice protein denaturation degree is smaller than the traditional soaking and cooking rice.The degree of degeneration of no waxy rice and waxy rice is basically the same. Use ofdifferent heating medium has no effect on rice protein denaturation.The change of oil content in rice during roasting is mensurated. It is found thatvolatilization of free oil is larger and volatilization of bound oil is smaller. No waxy riceoil difficultly volatile and waxy rice oil easily volatile. Comparative study on the effects of different feeding methods on the rice winefermentation. Preliminary identification of fed batch fermentation method is suitable forroasted rice wine brewing technology. Through the determination of physicochemicalproperties, sensory analysis and flavor analysis that the use of roasted rice wine with thetraditional flavor can be brewed. But with the traditional rice wine, there are still somegaps. Therefore roasted rice by superheated steam can be used for rice wine production.更多还原