With the development of marketing, time-temperature indicator (TTI) is applied to monitor the storage temperature and time to predict the shelf-life of food by irreversible color change. This study mainly focused on developing the solid-type enzymatic time temperature indicator as a first exploration on printable TTI. It was based on the phenomenon that starch would change its color into blue when meets iodine, and the hydrolysis of enzyme make the color turn to colorless gradually. Combining the microencapsulation technology to immobilize enzyme, several TTIs with different formulas were achieved, and hopefully to be applied on different foods, whose storage temperature is 4 and their shelf-life could be 5-6 days. Chilled pork meat was chosen as an indicating target to figure out a suitable specific TTI by activation energy comparing and lasting time matching.

• Jing Qian(Department of Packaging Engineering, School of Mechanical Engineering, Giangnan University)