米饭回生研究(Ⅱ)米饭回生动力学

Research on the Retrogradation of Cooked Rice(II) Retrogradation Kinetics of Cooked Rice

回生动力学研究在淀粉及谷物食品的贮存保鲜方面具有重要意义。Avrami模型可用于描述淀粉回生过程中的结晶行为，通过对模型参数k（结晶速率常数）和n（Avrami指数）的确定与分析，可以了解在结晶过程中直链及支链淀粉分子对晶体的成核方式、晶核密度和晶体生长方式的影响。在此基础上，本文研究了含水量对米粉糊及米饭回生速率的影响。结果表明在实验范围内，体系中含水量的减少主要是通过提高瞬时成核的强度（使n降低）和提高晶核密度（使k提高）来提高淀粉回生速率的。

<Abstrct> The Avrami model was used to describe the recrystallization process of starch during retrogradation with deterdrination and analysis of model parameter k(crystallinc rate constant) and n (Avrami exponent). An investigaion on the influence of moisture content to the retrogradation behavior of rice flour paste and cobked rice has been carried out. The results showed that through intensifying the formation of instantaneous nuclei (reducing n) and increasing the nuclei density (increas ing k), decreasing moisture content promoted the rae of staroh retrogradation in the system.