The Test Study On Using Extruded Maize Without Germ For Producing Alcohol

The substitution of extrusion technology for traditional cooking technology as the method of the pretreatment process of corn material has many advantages, such as a high rate of material using, a quick fermentation of worts, a simplification technology and a low energy consumption. This technology has vast available vistas in alcohol industry.First, the influence of parameters of extrusion system on reducing sugar was studied by quadratic orthogonal retation combination design test of four factors and five levels.The reducing sugar after sacchrifaction is the observing indixes.Second, the influence regularity of system parameters and the additive quantity of yeast on the alcohol yield of extruded maize without germ by method of the quadratic orthogonal rotating combinatorial design of five factors and five levels was studied. The optimized parameters of extrusion system and the appropriate additive quantity of yeast were obtained. The optimized system parameters of extrusion are follows: the diameter of the die nozzle O ^llmm , extrusion temperature of material T=200癈 , moisture of fed maize without germ W=19 %, speed of screw n=240r.p.m.and the appropriate additive quantity of yeast is 0.4%.Third, the comparison between extrusion process and traditional cooking process.The test results indicate that traditional cooking process could be substituted by extrusion process. It was provided for the reducing of energy consumption in alcohol process.Fourth, the mechanism of substitution of extrusion technology for cooking technology was initially discussed by the determination of gelanization of extruted maize without germ. Yeast-growth was observed in the extrudate wort , and yeast-growth curve was drawn. The curve can be applied to controlling yield quantity of the alcohol fermentation process in the maize extrudate solution .Fifth, the conclusion was obtained through the experiment of yeast cultivated. It is that the yeast was suitable for the alcohol fermentation after activated 20 minutes and cultivated 1 .6 hoursFinally, the relationship between the alcohol yield of starch of extruded maize without germ of starch and the content of reducing sugar was studied. The relationship between the alcohol yield of starch of extruded maize without germ of starch and the gelatinization of starch of extrudate of maize without germ was investigated. The degree of available saccharification of extrudate was discussed.Graduate student: Guan Zhengjun Major: Agricultural product processingand storage engineering Supervisor : Prof. Shen Dechao...