Time-temperature indicators

Ciba's OnVu time-temperature indicators (TTIs) show at a glance the freshness of perishable goods. The latest generation of OnVu TTIs have been designed for chilled products with shelf lives of up to 20 days.

The most common causes of spoilage of chilled food are too high temperatures during storage and transport. OnVu TTIs allow producers, retailers and consumers to check at a glance whether perishable products have been correctly transported and stored, thus helping to enhance consumer convenience and confidence, strengthen the reputation of brands using them and optimise shelf life.

OnVu TTIs are currently supplied as labels and will in future also be available as printing inks for application straight on the package. TTIs can in principle be used for any product that is sensitive to temperature. They show clearly whether the chill chain has been maintained, by recording the effects on the product of temperature fluctuations over time. Every indicator is tailored to the specific shelf life and optimum storage conditions of the product it is designed to monitor. By providing essential information on chill-chain history, OnVu TTIs can also help to optimise shelf life, since suppliers and retailers will no longer need to discard products prematurely to cover for potential spoilage, caused, for example, by incorrect storage.

Developed jointly by Ciba and FreshPoint, OnVu TTI technology relies on the properties of pigments that change colour over time and if temperatures fluctuate. The label or printed display contains a reference colour in addition to the OnVu TTI. Once activated by a suitable light source, the TTI first becomes dark and then grows progressively lighter as time passes and also if and when the ambient temperature rises. Exposure to higher temperatures than those prescribed, therefore, accelerates the lightening process of the colour. When the activated colour attains the same shade as the reference, the product has reached the end of its shelf life.