Extrusion processing of high amylose potato starch materials
Extrusion processing of high amylose potato starch materials
复制标题
高直链马铃薯淀粉原料的挤压加工
DOI：
10.1016/j.carbpol.2006.01.033
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发表时间：
2006
影响因子：
11.2
通讯作者：
M. Rigdahl
中科院分区：
文献类型：
--
作者：
Mats Thuwall;A. Boldizar;M. Rigdahl
将天然高直链马铃薯淀粉和普通马铃薯淀粉在Buss共揉挤出机中以淀粉与甘油的比例分别为100:45和100:30制备热塑性淀粉。在23°C的不同相对湿度条件下，材料的含水量也不同。混合后，用Brabender实验室挤出机将化合物挤出成薄片。在53%的相对湿度条件下，热塑性高直链淀粉材料的熔体粘度高于普通马铃薯淀粉材料。将HAP的含水率从27%提高到30%（重量比），使其熔体粘度降至与普通马铃薯淀粉（含水率为28%）相同的水平。一般来说，高直链淀粉材料比普通淀粉基热塑性材料更难以挤出。高直链淀粉在挤压过程中遇到的主要问题是流动不稳定、熔体韧性不足和模具堵塞。通过增加含湿量，提高螺杆压缩比，提高螺杆转速，减少或消除了这些问题。然而，只有当淀粉与甘油的比例为100:45时，才能获得可接受的挤出结果。这种高直链淀粉材料的挤压片在室温和53%相对湿度下的断裂应力约为5MPa，而普通马铃薯（热塑性）淀粉的相应值为3MPa。高直链淀粉材料的断裂伸长率也较高。从淀粉材料的剩余结晶度的角度对结果进行了讨论。
Thermoplastic starch was prepared by mixing native high amylose potato starch and normal potato starch in a Buss co-kneading extruder at starch to glycerol ratios of 100:45 and 100:30. The materials were also conditioned to different moisture contents at different relative humidities at 23°C. After the mixing, the compounds were extruded into sheets with a Brabender laboratory extruder. The thermoplastic high amylose materials exhibited a higher melt viscosity than the normal potato starch materials when conditioned at 53% relative humidity. Increasing the moisture content in HAP from 27% to 30% (by weight) lowered the melt viscosity to the same level as that of normal potato starch with a moisture content of 28%. In general, the high amylose materials were more difficult to extrude than the thermoplastic material based on normal starch. The main extrusion problems encountered with the high amylose starch were unstable flow, insufficient melt tenacity and clogging of the die. By increasing the moisture content, increasing the compression ratio of the screw and increasing the rotation rate of the screw, the problems were reduced or eliminated. However, only with a starch to glycerol ratio of 100:45 was an acceptable extrusion result obtained. Extruded sheets of such high amylose materials had a stress at break of about 5MPa at room temperature and 53% relative humidity, whereas the corresponding value for normal potato (thermoplastic) starch was 3MPa. The elongation at break was also higher in the case of the high amylose material. The results are discussed in terms of residual crystallinity of the starch materials.