Ghorpade V M, Bhatnagar S, Hanna M A
Industrial Agricultural Products Center, Department of Biological Systems Engineering, University of Nebraska, Lincoln 68583-0730, USA.
Plant Foods Hum Nutr. 1997;51(2):109-24. doi: 10.1023/a:1007951612581.
Commercially available corn starches containing 0, 25, 50 and 70% amylose were extruded with 10, 20 and 30% soy protein isolate (SPI) or wheat gluten (WG) at 22% moisture content (dry basis) in a C.W. Brabender single screw laboratory extruder using a 140 degrees C barrel temperature and a 140 rpm screw speed. True, solid and bulk densities; percent total, closed and open pores; and shear strengths of the extrudates were determined. The microstructures of the extrudates were studied by scanning electron microscopy (SEM). The total pores of the extrudates were affected significantly (p > F = 0.0001) by type of protein (SPI or WG) and starch amylose. The open or closed pores, were affected by protein type only. The interaction between amylose and protein contents was highly significant (p > F = 0.0001). In general, the total pores and bulk densities were higher for WG-starch extrudates compared to SPI-starch extrudates. These values decreased as amylose content increased from 0 to 25% and then increased thereafter. The open pores, on the other hand, increased with increasing protein content from 10 to 20% and then decreased. Extrudates containing WG had higher shear strengths than those containing SPI.
将含有0%、25%、50%和70%直链淀粉的市售玉米淀粉，与10%、20%和30%的大豆分离蛋白（SPI）或小麦面筋（WG）在22%水分含量（干基）下，于C.W.布拉本德单螺杆实验室挤出机中进行挤出，机筒温度为140℃，螺杆转速为140转/分钟。测定了挤出物的真密度、固体密度和堆积密度；总孔隙率、闭孔率和开孔率；以及挤出物的剪切强度。通过扫描电子显微镜（SEM）研究了挤出物的微观结构。挤出物的总孔隙率受蛋白质类型（SPI或WG）和淀粉直链淀粉的显著影响（p > F = 0.0001）。开孔或闭孔仅受蛋白质类型的影响。直链淀粉和蛋白质含量之间的相互作用非常显著（p > F = 0.0001）。一般来说，与SPI-淀粉挤出物相比，WG-淀粉挤出物的总孔隙率和堆积密度更高。随着直链淀粉含量从0%增加到25%，这些值下降，此后又增加。另一方面，开孔率随着蛋白质含量从10%增加到20%而增加，然后下降。含有WG的挤出物比含有SPI的挤出物具有更高的剪切强度。
