湿面老化动力学研究

Study on retrogradation kinetics of LL noodles

利用差示量热扫描仪测定在不同储藏温度条件下(-4、15、25、35℃)的湿面老化焓,应用Avrami模型描述淀粉在回生过程中的结晶行为,研究了贮存温度对湿面淀粉老化速率和淀粉结晶成核方式的影响。通过对模型线性回归后得到结晶速率常数k和Avrami指数n。结果表明,在本实验贮存温度区间内,湿面淀粉的老化结晶速率k随着贮存温度的升高而逐渐减小;在-4～15℃的贮存温度区间内,Avrami指数n均小于1,表明其结晶方式是瞬间成核,在25～35℃区间内,1<n<2,表明以自发成核为主。

DSC was used to determine the retrogradation enthalpy of LL noodles stored at different temperatures of -4,15,25 and 35℃.Nucleation ways of starch in LL noodles were depicted by Avrami model, effects of storage temperature on retrogradation rate and crystallization ways of starch in LL noodles were studied. Regression analysis of Avrami model recommonded crystalline rate constant k and Avrami exponent n. Conlusions were acheived that at exprimental range of-4℃ to 35℃,the retrogradation rate of starch decreased while temperature was increasing,and that at the short range of-4℃ to 15℃,the crystallization way was instantaneous nucleation suggested by Avramin index less than 1.While the storage temperature at the rang of 25℃ to 35℃,1 〈 n 〈2,which indicated the way of crystallization is spontaneous nucleation mainly.