Whether they indicate the loss of packaging integrity, the ripening stage of packaged fruits, or the presence of pathogenic microorganisms, intelligent materials and objects must reveal information related to the evolution of packaged foods, that is, the emergence (or disappearance) of induced physicochemical or biological modifications through markers (also known as analytes or irritants).
The following figure summarizes the different elements to consider when developing intelligent systems to best meet the required functions, such as providing information about packaging integrity, safety or packaged food quality. To this end, it is important to determine the markers to be monitored throughout the life cycle of packaged food. These may be related to the environment of the food, such as the time of exposure to a specific temperature (time / temperature), or even modified atmosphere (gas content in the headspace); It also has an impact on the evolution of food itself. under these circumstances,
Classification of intelligent packaging
Intelligent packaging can be divided into two categories, depending on whether it responds to the changes of packaging products themselves or to the changes of their environment: direct or indirect indicators of food quality.Classify smart packaging according to the information to be disclosed.
indirect indicators of packaging product quality
However, in today's market, time temperature indicators dominate. Their effectiveness is based on reaction kinetics consistent with the expected application. In other words, the effect of temperature on these dynamics must be equal to that of temperature
And the time scale of these dynamics must correspond to the time scale of packaged food deterioration. Most of these indicators are based on color changes, which can be perceived by the naked eye. The reactions involved are diverse, and the business examples are shown in the figure below:
Illustrations of various color time and temperature indicators
Checkpoint discussed above ® Based on enzymatic hydrolysis, topcryo from traceo cryolog affects the growth of microorganisms (selected according to the target food) on the substrate, changes the pH value of the medium and leads to color change, fresh check ® Through the temporary time company, the polymerization of diacetylene monomer (colored polymer) and even the migration of blue ester (butyl stearate, dimethyl phthalate, etc.) on blotting paper with flow time varying with temperature (relative to the melting temperature of the selected ester) and the time of 3M monitormarktm.