没食子酸时间温度指示器的制备及性能研究

Preparation and Properties of Gallic Acid Time Temperature Indicator

中文关键词: 没食子酸(GA)  时间温度指示器(TTI)  活化能

英文关键词: gallic acid (GA)  time temperature indicator (TTI)  activation energy

中文摘要:

      目的 基于没食子酸(Gallic Acid，GA)的特性，制备可以通过调节pH值改变活化能的时间温度指示器(Time Temperature Indicator，TTI)，以期为新型TTI的开发提供参考。方法 制备不同GA浓度、pH值的GA TTI，在恒温条件下储藏，探究GA浓度和pH值对TTI颜色变化的影响。测定制备TTI的吸光度值，构建TTI颜色响应的温度动力学模型，并确定其动力学参数和活化能。结果 GA浓度为0.02 mol/L时TTI对温度最为敏感，故制备出GA浓度为0.02 mol/L，pH值为6.5、7.0、7.5、8.0的4种TTI。pH值为6.5时，TTI从无色变为黄褐色;pH值为7.0时，TTI从无色变为草绿色;pH值为7.5和8.0时，TTI从无色变为蓝绿色。利用吸光度计算出的4种TTI的活化能分别为85.99、44.93、29.57、25.03 kJ/mol。结论 不同pH值的GA TTI颜色变化明显，且GA TTI活化能有一个较大的范围，适用食品类型广泛，有潜力作为一种新型TTI。

英文摘要:

      The work aims to prepare a new time-temperature indicator (TTI) of which the activation energy can be changed by adjustment of pH value based on the properties of gallic acid (GA), so as to provide reference for the development of new TTI. The GA TTIs with different GA concentrations and pH values were prepared and stored at constant temperature. The effect of GA concentration and pH value on the color change of TTIs was explored. The absorbance value of prepared TTIs was determined, and the chemical kinetic model of TTI color response was established, and their kinetic parameters and activation energy were determined. TTI was most sensitive to temperature when GA concentration was 0.02 mol/L, so four kinds of TTIs with GA concentration of 0.02 mol/L and pH value of 6.5, 7.0, 7.5 and 8.0 were prepared, respectively. At pH 6.5, the colorless TTI eventually turned into earth-yellow, at pH 7.0, the colorless TTI eventually turned into grass green and at pH 7.5 and 8.0, the colorless TTI eventually turned blue-green. The activation energies of four kinds of TTIs calculated by absorbance were 85.99, 44.93, 29.57 and 25.03 kJ/mol, respectively. The color of GA TTI changes significantly at different pH values. The activation energy of GA TTI has a large range that is suitable for a wide range of food types, so GA TTI has the potential to act as a new TTI.