高能球磨对大米淀粉流变特性的影响

为探究高能球磨处理对大米淀粉流变行为的影响。利用高能球磨对大米淀粉分别处理5、10、30 min及60 min,以未球磨处理大米淀粉为对照,研究不同时间球磨处理对大米淀粉的形貌、颗粒大小及流变学特性的影响。结果表明,湿法高能球磨处理使大米淀粉颗粒破损、表面变得粗糙,球磨及未球磨对照大米淀粉糊均表现为假塑性流体特征,随着球磨时间延长,淀粉糊的假塑性增强、流动性变大,大米淀粉糊的弹性模量G′和黏性模量G′′开始增加的温度逐渐向低温方向偏移,温扫过程中的最大弹性模量G′max和最大黏性模量G′′max不断降低;球磨处理和未球磨处理大米淀粉糊黏弹性均随频率增加而加大,随着球磨时间延长,相应频率下的G′和G′′不断减小,球磨30 min以上样品趋于恒定;球磨及未球磨对照大米淀粉糊均是触变体系,随着球磨时间延长,大米淀粉糊的触变性减弱。

Effect of High Energy Ball Milling on Rheological Properties of Rice Starch

To explore the effect of high-energy ball milling on rice starch,rice starch was milled with high-energy ball milling for 5 min,10 min,30 min and 60 min respectively,and the untreated rice starch was used as control.The surface morphology,particle size and rheological properties of rice starch were studied.The results showed that the high-energy ball milling caused the surface of rice starch rougher and damaged the starch particles.The untreated and milled starch pastes were all the pseudoplastic fluid,and the pseudoplasticity became stronger with increase of the ball milling time.With the extension of ball milling time,the temperature at which the elastic modulus (G’) and viscous modulus (G") of rice starch beginning to increase shifted to the lower temperature,and the maximum elastic modulus (G’max) and the maximum viscous modulus (G"max) decreased gradually.The viscoelasticity of all rice starch pastes increased with the increase of frequency,the G’ and G" of rice starch paste decreased at the corresponding frequency with the increase of the milling duration.The untreated and milled rice starch pastes displayed thixotropic behavior,and the areas of hysteresis loops decreased with increasing milling time.