不同品种黑小麦淀粉理化性质研究

对黑小麦淀粉的颗粒性状、透明度、膨胀势、直链淀粉含量、冻融稳定性、糊化特性等理化性质进行了研究.结果表明:黑小麦淀粉颗粒较大,多呈圆球形或卵圆形,尺寸为5～25μm;总淀粉含量与对照小偃6号相当;直链淀粉和破损淀粉含量均高于对照小偃6号.黑小麦淀粉具有较好的膨胀特性,但透明度和冻融稳定性较差.黑小麦淀粉的起始糊化温度较高,峰值黏度为0.340～0.483Pa.s,其热糊和冷糊稳定性均比对照品种差,但加入NaCl和蔗糖均能提高黑小麦淀粉糊的热糊稳定性,减缓冷却过程中淀粉的老化,其中起始糊化温度随NaCl浓度的增加而逐渐升高,峰值黏度、回生值、破损值均随NaCl浓度的增加而减小.起始糊化温度、峰值黏度随着蔗糖浓度的增加而增大,破损值和回生值却随蔗糖浓度的增加而下降.另外,随着pH值的升高,黑小麦淀粉的起始糊化温度逐渐降低,峰值黏度、破损值和回生值急剧升高.

Physicochemical Properties of Starch from Ten Black Kernel Wheat Varieties

The physical and chemical properties of black kernel wheat starch granule,including shape,transparency,swelling power,amylose content,freeze-thaw stability,and viscosity properties were studied in this paper to provide theoretic basis for further development and utilization of black kernel wheat starch.The results indicated that black kernel wheat starch granule was big,assuming elliptic and spherical type,the range of granule size was 5~25μm,total starch content was the same as xiao yan 6,while amylase and damaged starch content were higher than xiao yan 6.The black kernel wheat starch showed good swelling power,while poor transparency and freeze-thaw stability.The beginning gelatinization temperature was high,the maximum viscosity was 0.340～0.483Pa·s,and the hot paste stability and cold paste stability of black kernel wheat starch were poorer than that of check varieties starch.The hot paste stability and cold paste stability could be improved when adding NaCl and sucrose.The beginning gelatinization temperature increased with the increase of NaCl concentration,but the maximum viscosity,breakdown and setback decreased with the increase of NaCl concentration.The beginning gelatinization temperature and maximum viscosity increased with the increase of sucrose concentration,but breakdown and setback decreased with the increase of sucrose concentration.In addition,with the pH increases,the beginning gelatinization temperature gradually reduced,the maximum viscosity,breakdown and setback sharp rised.