As the perishable goods are packaged, an OnVu™ TTI is applied and activated using an ultra violet (UV) light source. A filter is then placed over the label to protect it from deliberate or accidental recharging. The label activation and filter placement processes are carried out automatically by a range of OnVu™-capable label dispensers that have been developed to meet industry needs.

Using color to indicate freshness

The OnVu™ consumer indicator consists of an apple shape with a center and a shell. Upon activation with UV-light, the center of the apple turns dark blue. This forms a striking contrast with the light color of the surrounding shell of the apple (the reference color). The clear contrast between the active indicator and the reference color indicates that the product is safe to consume. The active center of the apple then begins to become progressively lighter over time, and with exposure to temperature. Exposure to excessive temperature fluctuation accelerates the lightening process.


As long as the center of the apple is darker than the surrounding reference color, the product is fresh. Once the center becomes lighter in color than the surrounding shell of the apple, the product is no longer safe to consume. The OnVu™ TTI range also includes an indicator targeted at assisting manufacturers, distributors and retailers in monitoring and improving their internal chill-chain practices.

Based on the same technology as the OnVu™ consumer label, OnVu™ Logistics is designed to track the aggregate temperature history of cartons/crates of perishable goods at various handover points within the chill chain. As a result, all parties in the chill chain now have a simple and effective tool to intelligently manage perishable inventories, ensuring that goods are sold at their freshest, and decreasing the amount of temperature-related perishable shrinkage.

How to use

The reliable indicator display consists of a heart shape con-tained within an apple. First, the display is activated with a UV light. Once activated, the heart turns a dark hue. This forms a striking difference with the light color of the surrounding apple. These clearly contrasting colors indicate that the produce is safe to consume.

The heart becomes progressively lighter over time. Exposure to excessive temperature fluctuation accelerates the lighten-ing process. You can see how this works on the accompany-ing chart. The color of the heart is a simple visual indication at a glance.

TTI Presentation (PDF)