【摘要】 明确直链淀粉和支链淀粉老化对水分结合状态的影响，有助理解和调控淀粉老化。为探究不同直支比淀粉凝胶在老化过程中的水分分布差异，本研究将提取的直链淀粉和支链淀粉分别按0∶100、25∶75、50∶50和100∶0混合后，制成水分含量为60%的淀粉凝胶，采用低场核磁共振分析凝胶在储存过程中的水分分布状态，利用差示扫描量热仪表征淀粉老化焓值。结果表明，凝胶中直链淀粉含量越高，水分的横向弛豫时间（T₂）值越短，多指数模型中T₂₁、T₂₂和T₂₃越低；在低直链淀粉含量的凝胶中，强结合水的横向弛豫时间更短，而直链淀粉含量为100%时对应强结合水比例最高。弱结合水的流动性降低与老化焓值的增加密切相关。老化焓值的增加趋势随直链淀粉含量的增加而减弱，直链淀粉含量100%对应凝胶老化焓值最小且整体变化不显著。综上，强结合水与弱结合水的分布与老化焓值呈显著相关关系；直链淀粉的快速老化影响水分的整体流动性，支链淀粉形成的强结合水则更为紧密。本研究结果为进一步研究淀粉老化与水分微观状态之间的关系提供了数据支撑。更多还原

【Abstract】 Defining the effects of amylose and amylopectin retrogradation to the changes in water states,could contribute to the clarification and regulation of starch retrogradation process.To investigate the differences in water distribution during the retrogradation process of starch gels with varying amylose-to-amylopectin ratios,amylose and amylopectin were extracted and mixed in the ratio of 0∶100,25∶75,50∶50 and 100∶0 to make starch gels with the same moisture content of 60%,respectively.Low-field nuclear magnetic resonance was used to analyze the distribution of water in different states during storage,and differential scanning calorimetry was utilized to characterize the retrogradation enthalpy of starch.The transverse relaxation time （T₂） of water,and T₂₁,T₂₂ and T₂₃ in the multi-exponential model were negatively correlated with the amylose content in the gel.Compared to other groups,the transverse relaxation time of strongly bound water was shorter in gels with low amylose content,and the proportion of strongly bound water was the highest when the amylose content was100%within gel.The reduction in mobility of weakly bound water was highly related to the increase in retrogradation enthalpy.The trend of increasing retrogradation enthalpy diminished as the amylose content increased,with gels containing 100%amylose exhibiting the lowest overall enthalpy and insignificant changes.In conclusion,the distribution of strongly and weakly bound water were significantly correlated with retrogradation enthalpy.The overall mobility of water was effected by rapid aging of amylose,while more tightly bound water was formed in amylopectin.This study provides data basis for further investigation on the relationship between starch retrogrdation and the microstate changes of water.更多还原