面向冷链物流农产品品质感知的TTI动态校准方法

Dynamic Calibration Method for Time Temperature Indicator Towards Quality of Agricultural Produce under Cold Chain

摘要:

时间-温度指示器(TTI)是一种可以跟踪冷链物流温度历程的智能装置，可以指示相应的农产品品质。但现有的TTI匹配条件在一定程度上限制了TTI的应用范围，即使TTI满足了传统匹配条件的要求，但应用效果也会受到农产品采收品质波动的影响。通过使用反应动力学方程和等量线方法，在原有的匹配过程中引入了TTI的校准过程，并借此推导TTI匹配所需的基本条件，以及校准过程所需的参数。结果表明，TTI匹配性判断所需的基本条件仅为农产品品质与TTI的反应活化能相等，或两者等量线存在比例关系。在此前提下，利用公式推导或等量线的绘制过程，可以求得静态校准和动态校准时所需的相关参数，经过校准后的TTI即可与对应的食品完成匹配。校准过程的引入可以显著扩大TTI的适用范围。除此之外，动态校准模型还可以缩小处于变化中的TTI和农产品对应品质之间的差值，提高TTI指示货架期的精确性。最后，通过使用两种酶型TTI、两种不同激活条件的化学型TTI和玫瑰香葡萄进行验证实验，实验结果证明经过合理校正之后TTI的等量线普遍与玫瑰香葡萄的品质等量线更接近，对其指示效果精准。

Abstract:

Time temperature indicator (TTI) is an intelligent tool to monitor and record directly the time-temperature history of cold chain and indicate quality of corresponding agriculture produce. Because of the restriction of classic matching condition, TTI has not been widely used in a wide variety of agricultural produces. Even when the TTI satisfies the conditions, the reliability of application is significantly affected by the unstable primary quality of agricultural produces. The application of TTI is expanded through adjusting its parameters, and determining the requirements for matching with agricultural produces and the calibration procedure of TTI. The result deduced through the reaction kinetics equations and contour diagram indicated that the only matching condition was activation energy of TTI should equal to the parameter of agricultural produce, or there existed a proportional relationship between the contour lines of the two products. Besides, an adjusting process of TTI should be used with the new matching condition together. Considering a change of the state of TTI and agricultural produces, the calibration process was divided into two parts: first was the static model with the two produces’ state which were static, and the second was the dynamic model with both of the two produces were in constant change. It provided corresponding theory and methods by using the Arrhenius equations and contour diagram for the two calibration process respectively. These calibration methods can expand the application of TTI and improve the precision and reliability of monitoring the quality of agricultural produces. Finally, the validity and reliability of the calibration theory were illustrated with an example by using two types of enzymatic TTIs, two types of chemical TTIs and Muscat grape.