[关键词]
[摘要]
为了明确微波在淀粉物料加热过程中的机制,本实验选取典型B型淀粉-马铃薯淀粉作为研究对象,根据微波加热的升温规律,建立和评价可对照的加热模型,运用低场核磁共振技术,以Carr-Purcell-Meiboom-Gill (CPMG)脉冲序列为手段,通过对微波加热、快速加热和慢速加热等三种加热方式下样品的横向弛豫时间(T2)衰减曲线进行PCA分析,利用多指数回归拟合计算得到T2,从而分析样品内部水分的变化信息,研究微波加热对马铃薯淀粉颗粒内部水状态及分布的影响。结果表明三种加热方式对样品T2的影响具有显著性差异,具体表现为在糊化前期及糊化刚开始阶段,微波加热对马铃薯淀粉颗粒内水分分布有显著影响,本实验一定程度上证明了微波的特殊效应在该阶段对马铃薯淀粉内氢键的破坏有促进作用。
[Key word]
[Abstract]
In order to investigate the mechanism of microwave heating, potato starch was selected as the research sample because of its typical B-type crystalline structure. Based on the characteristics of the microwave heating process, a control heating model was established and evaluated. Using 1H NMR technique, Carr-Purcell-Meiboom-Gill (CPMG) pulse sequence and principal component analysis (PCA) to obtain the original transverse relaxation curves of samples that underwent microwave, rapid, and slow heating. The transverse relaxation time (T2) was calculated through multi-exponential regression to analyze the variation patterns of water in the samples in order to study impact of microwave heating on the water state and distribution in potato starch granules. The results showed that there were significant differences in T2 with all three types of heating; microwave heating exerted a particularly significant impact on moisture distribution within the potato starch granules in the early stages of gelatinization. To a certain extent, this study showed that the special effects of microwave accelerated the destruction of hydrogen bonds at this stage.
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[基金项目]
国家自然科学基金(青年项目)资助项目(31301504);“十二五”国家科技支撑计划项目(2014BAD04B03);高等学校博士学科点专项科研基金(新教师类)(20130093120011)