挤压膨化对玉米粉发酵的影响

Effect of extrusion on fermentation of corn flour

以玉米碴为原料，植物乳杆菌P8菌粉为发酵菌，考察了挤压膨化对玉米粉发酵的pH、总酸度、挥发酸的影响，并测定了玉米粉、膨化玉米粉的比表面积和孔径分布。结果表明，挤压膨化使玉米粉比表面积增加178％，孔径从2．89-17．93nm增大到3．42-20．47nm；与玉米粉相比，膨化玉米粉发酵至pH3．80时间约缩短12h、发酵至酸度13．5g／kgN-间缩短6h；膨化增大了植物乳杆菌的作用面积，加快了发酵速度。

The corn ballast and Lactobacillus plantarum P8 powder were used as the raw material and the fermentation bacteria, respectively. The influence of extrusion on pH,total acidity and volatile acid of fermented corn flour was examined ,and the specific surface area and pore size distribution of the raw and extruded corn flour were determined. The results indicated that extrusion could enlarge the specific surface area of corn flour by 178%,and increase the pore size from 2.89-17.93nm to 3.42-20.47nm. Compared with the raw corn flour, the fermentation time of extruded one to pH3.8 was reduced by 12h,and the fermentation time to acidity value of 13.5g/kg was shortened by 6h. The contact area of corn flour with Lactobacillus plantarum was increased due to the enlarged surface area,which consequently accelerated the fermentation rate.