【作者】 李宏军；

【导师】 申德超；

【作者基本信息】 东北农业大学 ， 农产品加工与贮藏工程， 2001， 硕士

【摘要】 本文采用挤压膨化预处理技术代替传统玉米胚浸油生产过程中的轧坯预处理工艺，对新的玉米胚挤压膨化预处理技术的工艺参数进行了系统的研究，以达到降低生产成本，减少残油率，提高浸出效率的目的。 1，本文通过四因素五水平二次正交旋转组合试验设计，探讨了用于浸油的玉米胚挤压膨化预处理过程中的套筒温度、模孔孔径、物料含水率、螺杆转速等挤压系统参数对考察指标残油率、蛋白质的NSI值、剪切强度和容重的影响规律。得到最佳挤压工艺参数：模孔直径φ=9mm，物料出口温度T=93℃，喂入物料水分含量W=13.3％，螺杆转速N=238 r.min^-1，在此条件下得出残油率的最优值为0.4％。 2，和传统工艺相比，挤压膨化预处理工艺可以使浸提时间缩短一半，膨化物的容重与轧坯和预轧样相比分别增加29.3％和13.8％，物料体积减少10％-30％，使原设备的浸出能力提高100％-120％。 3，在以残油率为主要考察指标的最优挤压系统参数下，测定了玉米胚粉碎粒度对残油率的影响，结果表明粉碎粒度取0.7705mm比较合适。 4，综合分析了挤压膨化物的剪切强度和5目以下的粉末含量与浸出过程中糊底问题的关系。在实验室条件下，基本上解决了传统工艺中常见的糊底问题。 5，应用植物显微技术，通过石蜡切片观察，对用于浸油的玉米胚挤压膨化预处理工艺的微观机理进行了探讨，指出了挤压膨化物比轧坯和预轧样浸提时间缩短、残油率低主要是因为挤压膨化后油料细胞壁破坏较彻底、油脂有明显的聚集现象以及水分瞬间汽化后形成大量的毛细孔道所造成的。 6，分析了半湿法和湿法玉米胚的组成和微观结构的差别，研究了湿法玉米胚挤压膨化前进行预轧和挤压膨化的可行性。更多还原

【Abstract】 In this paper traditional rolling and pre-press pretreatment process of corn germ was substituted by extrusion pretreatment Process parameters of the extrusion procedure were researched. The cost of production and the ratio of residual oil can be reduced, and the efficiency of solvent-extraction can be increased.1, The method of orthogonal rotation combination test design of four 1~ctors and five levels was applied to discuss the principle of the influence of parameters of extrusion system upon research indexes in this paper. These parameters include the temperature of the barrel, the diameter of the die nozzle, the moisture of material and the speed of the screw. Above indexes include the ratio of the residual oil, the value of NSI, shearing strength and volume weight of the extrudate. The optimum parameters of extrusion system are as follows: diameter of die nozzle is CJ)~9mm , extrusion temperature T?3t , moisture of material W=13.3%, speed of screw n=238 r.p.m.. The optimum value of the ratio of the residual oil is 0.40%.2, The time of solvent extraction will be reduced 50% and the volum?weight of the extrudate will be increased 30% and 100/ocompared with traditional rolling and pre-press pretreatment process. The capacity of solvent extraction of original extraction equipment will rise to I 000/o~1 200/c.3, Under the condition of optimum parameters of extrusion system, the influence of the diameter of particle on the ratio of the residual oil was studied .The results showed that theappropriate diameter of particle is 0.7705mm.4, The relationship between shear strength along with powders content of extrudate and sticking to the screen during the solvent extraction was synthetically analyzed. The problem of sticking to the screen in traditional process was partly solved under the condition of laboratoty.5, By the technology of paraffin section, micro-mechanism of extrusion corn germ used for solvent extraction of oil was studied. The result showed that the time of solvent extraction of oil is shorter and the ratio of residual of oil is lower when compared with traditional rolling and pre-press pretreatment of corn germ. Because the cell wall of fat was crashed completely, fat was accumulated, and lots of capillaries were formed as the moisture evaporates rapidly during extrusion process.6, The difference of ingredients and microstructure between corn germ with wet milling and corn germ with semi-wet milling was analyzed. The feasibility of pre-press of corn germ with wet milling processed before extrusion was studied.Graduate student: Li HongjunMajor:Agricultural product processing and storage engineeringSupervisor:Prof. Sheri Dechao更多还原