玉米淀粉制备中挤压联用亚硫酸浸泡预处理工艺优化

Pretreatment of Corn Starch by Extrusion Combined with Soaking in Sulfite Acid

为解决传统玉米湿磨工艺浸泡时间长、淀粉提取率低的问题,展开了挤压技术对玉米淀粉提取预处理的可行性研究。以淀粉提取率和淀粉纯度为考察指标,分别研究挤压温度、挤压水分、螺杆转速、H_(2)SO_(3)浸泡时间对玉米淀粉提取率和淀粉纯度的影响。在单因素实验的基础上,采用四因素三水平的响应面分析法确定玉米淀粉提取工艺。结果表明,玉米淀粉提取的最佳工艺为:挤压温度40℃、挤压水分53%、螺杆转速194 r/min、H_(2)SO_(3)浸泡时间14 h。在此条件下玉米淀粉提取率达到了93.25%,相比传统湿磨工艺提高了1.79%,生产时间缩短34 h。通过红外光谱(FT-IR)分析发现,采用挤压预处理并未导致淀粉化学结构的改变;扫描电镜(SEM)图像表明挤压制备的淀粉颗粒表面出现轻微褶皱和凹陷,但颗粒形状依旧保持完整。故挤压技术应用于玉米淀粉的分离提取是有效可行的。

In order to solve the problems of long soaking time and low starch yield in traditional corn wet milling process,the feasibility of extrusion technology as pretreatment for corn to improve the starch extraction was carried out.The extraction rate and the purity of starch were studied by changing the extrusion temperature,extrusion moisture,screw speed,soaking time of H_(2)SO_(3).After the single factor experiments,the response surface analysis(RSA)method which had four factors and three levels were used to determine the extraction technology of corn starch.The results showed that,the optimum process of corn starch extraction was that:The extrusion temperature was 40℃,extrusion moisture was 53%,the screw rotation speed was 194 r/min and the soaking time of H_(2)SO_(3) was 14 h.The starch extraction rate reached to 93.25%in this method,which was 1.79%higher than that in traditional wet grinding process,and the production time was shortened by 34 h.Fourier transform infrared spectroscopy(FT-IR)showed that extruding pretreatment did not change the chemical structure of starch and the scanning electron microscope(SEM)images showed that,though slight wrinkles and depressions appeared on the surface of extruded starch granules,the shape of the particle remained intact.Therefore,it was confirmed that extrusion technology was effective to separate and extract the corn starch.