陕西主要荞麦品种的淀粉理化特性分析

Physicochemical properties of buckwheat Starch of Shaanxi Province

【目的】掌握陕西主要荞麦品种的淀粉理化特性,为荞麦淀粉的深加工利用及荞麦食品的加工提供依据。【方法】以陕西主要推广荞麦品种榆荞1号、榆荞2号、日本秋播荞麦以及甘肃红花荞麦为材料,以玉米和马铃薯淀粉为对照,采用水提法分离荞麦淀粉,研究荞麦淀粉的颗粒结构、组成、糊化特性以及凝胶质构特性。【结果】荞麦淀粉颗粒为多角形或球形,粒径1.4～14.5μm,大小较为一致,偏光十字较明显,微晶结构为A型;4个荞麦品种的直链淀粉含量为258.2～326.7g/kg,溶解度较低,介于马铃薯和玉米淀粉之间;荞麦淀粉的峰值黏度、起始恒温糊化阻力、起始降温糊化阻力、降温结束糊化阻力和50℃恒温结束糊化阻力均高于玉米淀粉,淀粉糊具有较强的热黏度稳定性、冷黏度稳定性和凝胶形成能力,抗酸、碱和耐剪切能力较强;荞麦淀粉糊的透明度较低,冻融稳定性较强,淀粉凝胶硬度、回弹性和粘聚性均较高,凝胶质构特性优良。【结论】荞麦淀粉的颗粒形态、微晶结构及淀粉构成与谷物淀粉相近,凝胶质构特性兼顾薯类淀粉和豆类淀粉的优点,是食品工业增稠剂、粘结剂和淀粉凝胶制品等的理想原料。

[Objective] The study was done in order to get physicochemical properties of starch from buckwheat mainly cultivated in Sbaanxi Province,and provide basis for the processing of buckwheat starch and buckwheat food. [Method] Main buckwheat varieties planted in Shaanxi Province, such as Yuqiao 1, Yuqiao 2,Japanese autumn buckwheat and red flower buckwheat, are taken as materials,and checked with maize and potato starch. Buckwheat starch is separated by water extraction and the granular structure, composition,gelatinization characteristic, gel texture characteristics of buckwheat starch are determined in the paper. [Result] The buckwheat starch granule is commonly polygonical or round shaped. The particle size scope is 1.4--14.5 μm,and the size is consistent. The polarization cross is clear. Its X-ray diffraction pattern is A-type. The amylose content of 4 buckwheat varieties is 258.2- 326.7 g/kg, the solubility is low,situating between the potato starch and the maize starch. The peak viscosity of buckwheat starch,the viscosity at the beginning of holding period, the viscosity at the beginning of coolinging period, the viscosity of final cooling period, and the viscosity at the end of 50 ℃ holding period are higher than those of maize starch. The starch paste has stronger thermo stability, cold stability and gel formation ability. As well,the acid and the alkali resistance, and bear cutting ability are strong. The transparency of buckwheat starch paste is low, the freeze-thaw stability and the gel formation ability are a bit strong. The hardness, resilience and cohesiveness of gel are high. The characteristic of gel texture is fine. [Conclusion] The granule shape, micro-crystal structure,starch composition of the buckwheat starch are similar to those of cereal starch. The gel texture characteristic has both yam and legume starch merits. The buckwheat starch can be used as ideal raw material of thickening agent, cementing agent and the starch gel product in the food industry.