加热时间对大米淀粉特性及抗性淀粉含量的影响

Effect of Heating Time on Starch Properties and Content of Resistant Starch in Rice

采用不同的加热时间对大米进行处理,并从加热处理过的大米中提取淀粉,采用电镜扫描仪、差示扫描量热仪、质构仪、流变仪等检测仪器研究加热时间对大米淀粉的颗粒形貌、热力学性质、凝胶特性、流变等性质的影响,采用酶解法测定加热处理过的大米中抗性淀粉的含量。结果表明:随着加热时间的延长,淀粉的膨润力与溶解度先增大后减小;加热时间在0～10min时,抗性淀粉含量减少,其范围为18.01%～8.10%;淀粉颗粒由单个独立的颗粒逐渐膨胀至相互粘连,糊化焓值降低;硬度、延伸性等都有不同程度的变化;淀粉糊的剪切稳定性降低。

In this work,rice was subjected to heating treatment for different time periods.Rice starch was extracted from heated rice and used to explore the effect of heating time on its granular morphology,thermomechanical properties,gel characteristics and rheology behavior measured using SEM,DSC,texture analyzer and rheometer.Resistant starch content was determined by enzymatic hydrolysis method.With prolonged heating time,the swelling power and solubility of rice starch initially increased,followed by a decrease,and the content of resistant starch decreased by 18.01%-8.10% during 0-10 min.Starch granular morphology was converted to adhesive granules from single independent granules due to swelling.Gelatinization enthalpy value also decreased from 5.862 to 0.532 J/g.Different changes in the hardness and elongation of starch from heated rice were also observed.In addition,the shear stability of rice starch paste changed downward.