甘肃主要杂豆淀粉理化特性分析

以甘肃产三角豌豆、白豌豆、小白芸豆、麻豌豆为材料，采用湿磨法提取淀粉，以玉米、马铃薯及绿豆淀粉为对照，对杂豆淀粉的理化特性进行分析。结果表明：参试杂豆淀粉颗粒多呈卵圆形，偏光十字较明显，多呈“X”形和斜十字形，部分淀粉颗粒呈现明显多脐点现象，平均粒径为21～29μm，其中三角豌豆淀粉的粒径最大而麻豌豆淀粉颗粒最小；淀粉颗粒的结晶类型与绿豆淀粉相同，为C型。其直链淀粉含量远高于玉米淀粉和马铃薯淀粉，且麻豌豆＞小白芸豆＞白豌豆＞三角豌豆淀粉。杂豆淀粉属限制型膨胀淀粉，起糊温度为72.6～78.8℃，且具有较好的热糊和冷糊稳定性，淀粉糊的透明度较高，但凝沉速度均极快，冻融稳定性也都较差。4种杂豆淀粉的理化特性与绿豆淀粉相近，可耐受高温处理，但不宜用于冷冻类食品的生产。

Physical and Chemical Properties of Starch from Major Legume Species in Gansu

In this work,physical and chemical properties of starches extracted by wet-grinding method from four major species of legume in Gansu province including pea(Pisum sativum L.),colored pea(Pisum sativum L.),white bean(Phaseolus vulgaris L.),Lathyrum hirsativa(Lathyrus sativus L.) were analyzed and compared with those of corn,potato and mung bean starches.Starch granules from these legume species under investigation were kidney-shaped with obvious birefringence in X-shape and cross-shape.Meanwhile,some starch granules revealed obvious umbilical points.The average size of starch particles was 21 — 29 μ m,and Lathyrum hirsativa starch particles revealed the largest size,but colored pea revealed the smallest size.The crystal type of legume starch granules was type C,so was mung bean starch.Compared with corn starch and potato starch,the contents of amylose in starches from the four legume species showed a considerable increase,and were ranked in descending order as follows: colored pea starch,white bean starch,pea starch and Lathyrum hirsativa starch.These legume starches displayed increases in swelling capacity and solubility with increasing temperature,which belonged to restricted type expansion starch.Their starting pasting temperature varied in the range of 72.6 — 78.8 ℃.Moreover,good hot paste and cold paste stability and high paste transparency were observed,while the retrogradation rate was fast and the freeze-thaw stability was poor.In conclusion,the properties of these legume starches were similar to those of mung bean starch.The legume starches tested in this study could tolerate heat treatment,but was not suitable for the production of frozen foods.