储藏温度对库尔勒香梨动态粘弹特性的影响

Storage Temperature Effect on Dynamic Viscoelastic Behavior of Korla Pear

采用Q800动态力学分析仪对4个温度水平下(-2℃、10℃、20℃和30℃)的库尔勒香梨果肉进行振荡剪切试验,以探讨温度对香梨果肉组织动态粘弹力学特性的影响,为香梨机械防损和质地品质保持提供指导。试验结果表明:不同温度下果肉的储能模量G′均远高于损耗模量G″,损耗正切tanδ(G″/G′)范围为0.082～0.095,表明香梨是以弹性为主导的粘弹体。香梨果肉组织的储能模量(G′)和损耗模量(G″)不受频率影响,均随温度下降呈上升趋势;当温差10℃时,各动态模量之间无显著差异,表明只有较大的变温幅度温才会对香梨果肉的粘弹特性和机械耐损性能有显著影响。

The effect of storage temperature on the dynamic viscoelastic properties of Korla pears was investigated to provide suggestions for mechanical damage prevention and textural quality maintenance of Korla pear.Samples were subjected to oscillatory shear test using Q800 dynamic mechanical analyzer by conditioned at four temperatures（-2 ℃,10 ℃,20 ℃ and 30 ℃）.Pear tissue behaved an elastic solid with storage moduli（G′） much higher than loss moduli（G″） over the entire frequency range（G″/G′≈0.082-0.095）.Both G′ and G″ were frequently independent,but increased with the decreasing of temperature.Values of the dynamic parameters（G″,G′） showed greater changes in samples exposed to a temperature range from-2 ℃ to 30 ℃,but changes were relatively insignificant when the temperature interval was 10 ℃ or less.Theseeffects suggest that temperature changes have influences on the viscoelasticity of pear tissue.Lower and higher temperatures can affect markedly the mechanical bruise susceptibility of Korla pear.