挤压膨化对豆渣可溶性膳食纤维的影响

以豆渣为原料，采用挤压膨化法对豆渣可溶性膳食纤维(soluble dietary fiber，SDF)进行研究。通过预实验，确定加入质量分数为20%的淀粉膨润剂。以挤压前后豆渣SDF的增量作为评定指标，研究豆渣含水率、物料温度及螺杆转速对豆渣SDF增加率的影响。结果表明：采用挤压膨化处理后，豆渣中戊糖较己糖、糖醛酸增幅大。通过正交试验，对工艺参数进行优化，结果表明：当含水率17%、螺杆转速150r/min、温度180℃时，SDF增加率可达到199.64%。此时，豆渣膳食纤维持水力为1430%、溶胀力为16.7mL/g，分别比豆渣原料提高了94%和125%。

Effect of Extrusion on Properties of Soluble Dietary Fiber from Soybean Meal

In order to maximize the incremental rate of soluble dietary fiber (SDF) in soybean meal after extrusion, single factor and orthogonal array design methods were employed to optimize extrusion conditions. Starch added at a level of 20% was found to be the best swelling agent. After extrusion, pentose content in soybean meal displayed a larger increase than the contents of hexose and alduronic. The optimal extrusion conditions were material moisture content of 17%, screw speed of 150 r/min and temperature of 180 ℃. Under such conditions, the incremental rate of SDF was 199.64%, and the water holding capacity and swelling capacity of extruded soybean meal were 1430% and 16.7 mL/g, respectively, which were 94% and 125% higher than unextruded soybean meal.