酪氨酸酶为基础的时间温度指示系统的初步研究

利用酪氨酸酶催化酪氨酸褐变的原理开发了一种新型的时间温度指示系统（TTIs）。在液态条件下,研究了不同温度对TTIs的褐变程度的影响。并且初步研究了TTIs在固相载体上的颜色变化。结果表明,反应体系在0℃和5℃时,经过0⁴8h体系的颜色由原来的无色变为褐色,最终变为明显的黑色（指示终点,灰度值42.05±2.00）,而在35℃条件下,体系的颜色经过4h就到达指示终点。进一步将酪氨酸固定在海藻酸钠-羧甲基纤维素钠混合薄膜上与酪氨酸酶液进行反应,颜色变化非常显著。实验证明,以酪氨酸酶为基础的酶型TTIs具有良好的发展前景。本研究为我国生鲜食品流通的监测提供了新的选择,为消费者选择物有所值的新鲜食品提供方便。 

Preliminary study on time-temperature indicator system based on tyrosinase

A new type of time-temperature indicators ( TTIs) based on enzymatic browning of tyrosinase had been developed.The absorbance curves and degrees of browning in liquid systems were determined at different temperatures. In addition, a preliminary study was conducted to analyze color changes when immobilized tyrosinase onto a solid phase carrier. The results showed that at 0℃ and 5℃, the color of the time temperature indicator system could shift from colorless to brown during 48 hours and finally turned into obvious black ( the end point of indication 42.05 ± 2.00) in the end. The whole process spent 48 h. However, at the condition of 35℃, only4 hours were needed for the whole process.The preliminary study which was conducted on a mixed sodium alginate-sodium carboxymethyl cellulose film manifested that there was a significant color change when reacted with tyrosine.All the results indicated that this kind of TTIs had a good prospect for development.It will provide another method in monitoring the flow of fresh food in China and it will offer a new option for consumers in choosing fresh food with reasonable price.