摘要
为了解超高压处理对莲子淀粉糊流变特性的影响,采用500 MPa高压处理莲子淀粉10～ 60min,使用流变仪研究了经不同超高压时间处理后莲子淀粉糊的流变特性.静态流变特性研究结果表明,莲子原淀粉及经不同超高压时间处理后的淀粉糊均为非牛顿流体,具有假塑性流体特征,其流变特性曲线可用Herschel-Bulkley方程进行较好的拟合.在相同处理条件下,莲子淀粉糊的表观黏度随着剪切速率的增大而减小,超高压处理前后的淀粉糊均存在剪切稀化现象,具有明显的触变性;动态流变特性研究结果表明,莲子淀粉糊的储能模量（G’）与损耗模量（G”）均随着处理时间的增加呈先上升后下降的趋势,在60 min处理条件下达到最小值.剪切结构恢复力试验结果表明,淀粉糊在经历低—高—低速剪切后较难恢复到原始结构.本研究结果可为超高压处理后的莲子淀粉的应用提供理论依据.
For understanding the effects of ultra high pressure （UHP） processing on the rheological properties of lotus- seed starch pastes, the starches have been treated by UHP（500 MPa） with different dwell time （10 -60 rain）. The rheological properties of lotus - seed starch pastes after treated with different dwell time have also been in- vestigated by rheometer. The static rheological properties investigation illustrated that both the native and UHP -trea- ted starches pastes were non -newtonian flow with pseudoplastic flow characteristic. Based on the results observed from flow curves, the Herschel - Bulkley theological model could be appropriate for the flow behavior of all starch pastes. On the same processing condition, the apparent viscosity of lotus -seed starch pastes decreased in line with increasing treatment time. The starch pastes exhibited shear -thinning pseudoplastic behavior before and after UHP treatment with significant thixotropy. The determination of dynamic rheologieal properties indicated that their storage modulus （G＇） and loss modulus （G＂） increased first and then decreased with the increasing treatment time. Further- more, storage modulus and loss modulus have reached the minimum value after 60 min treatment. The in - shear structural recovery test revealed that it is difficult for the UHP - treated pastes to recover original structure under low - high - low shear conditions. The research results will provide a theoretical basis for application of lotus - seed starch treated by UHP.
出处
《中国粮油学报》
EI
CAS
CSCD
北大核心
2014年第5期29-35,共7页
Journal of the Chinese Cereals and Oils Association
基金
福建省科技厅高校产学合作科技重大项目(2012 N5004)
福建省自然科学基金(2012J01081)
福建省高等学校科技创新团队支持计划(闽教科[2012]03号)
福建农林大学科技创新团队支持计划(cxtd 12009)
关键词
莲子淀粉
超高压
流变学
动态流变特性
静态流变特性
lotus - seed starch, ultra high pressure, rheology, dynamic rheological properties, static rheologi-cal properties
