哈斯鳄梨应力松弛力学特性及货架期预测模型

摘要

采用动态热机械分析仪(DMA)研究了不同贮藏温度下哈斯鳄梨果肉的应力松弛力学特性,并结合Maxwell模型以及动力学模型建立其货架期预测模型.结果表明,在5℃贮藏7d以内的力学松弛特性无明显变化,在8℃贮藏5d以后的力学松弛加快,而在25℃贮藏3d时,其力学松弛特性已经发生显著变化;构建了基于关键哈斯鳄梨力学松弛特征参数平衡弹性模量E0、主松弛时间τ1和阻尼体黏滞系数η的贮藏期预测模型,发现以主松弛时间τ1为特征值的货架期预测模型相对误差的绝对值为8.57％,较以平衡弹性模量、阻尼体黏滞系数建立的模型更为准确.%The ‘Hass’ avocado was tested by Dynamic Mechanic Analyzer(DMA) to study the stress relaxation properties at different storage temperatures.The Maxwell model and kinetics model were also used in establishing the prediction model for the shelf life.The results showed that there were no significant changes of stress relaxation property in 7 days when stored under 5℃.It was softened quickly after 5 days at 8℃.The stress relaxation properties changed significantly in 3 days at 25℃.The shelf life prediction models was established by extracting the equilibrium modulus of elasticity (E0),the main relaxation time(τ1) and the viscous coefficient(η) of samples.Among them,the model mainly based on relaxation time with relative prediction error of 8.57％.The model could predict the shelf life more accurate than the others.Therefore,the model has the potential in shelf life prediction of ‘ Hass’ avocado during the cold chain transportation and storage.