TIME-TEMPERATURE, FREEZE AND THAW INDICATORS

TIME-TEMPERATURE INDICATORS (TTI) FOR MONITORING FRESHNESS OF FOODS AND PHARMACEUTICALS

Perishables, such as foods and pharmaceuticals, have limited shelf-lives and they spoil/expire faster if stored at higher temperatures. Perishables are not always stored at the recommended temperatures. Using expired perishables can cause many health issues and even death. Hence, color changing time-temperature indicators (TTI) are used to monitor the shelf-lives of perishables. Dr. Gordhan Patel is a pioneer of the TTI technology. He co-invented color developing TTI based on the solid-state polymerization of diacetylenes in 1976 (US Patent # 3,999,936, which is the basis for TTI, known as VVM, Vaccine Vial Monitors of Temptime Corporation, Morris Plains, NJ, a division of Zebra Corporation). According to market studies, (i) the current market for VVM is ~$200 million/year and is projected to grow to ~$900 million/year in 2030 because of the increased use of vaccines and (ii) the total market for TTI labels is ~$800 million/year and is projected to grow to ~$1,400 million/year by 2030.

The VVMs of Temptime have two major drawbacks (i) ~50% percent of the cost is due to the cold (dry ice) storage/shipment requirements and (ii) they are very sensitive to UV/sun light and hence, they are used only for vaccines and not for monitoring the shelf-life of other perishables, which is a much larger market. The other commercially available TTI, e.g., moving boundary TTI based on diffusion of viscous inks are bulky, complex to manufacture, expensive, sensitive to humidity and one TTI uses a liquid.

A few new classes of TTI developed by JP Labs over the past 40 years have none of the above drawbacks. To meet market needs, JP Labs has developed two major classes of TTI: (i) Two-tape™ TTI and (ii) thermally activated Inact™ TTI. Both do not require cold storage, are not unaffected by UV light and humidity, and they are made by coating TTI inks using commercially available printing equipment. They can be stored for years at room temperature and activated when desired either by lamination or thermal activation. JP Lab’s TTI are human and machine (barcode & RFID) readable. The time required for the color change of the TTI can be varied from hours to years at room temperature or equivalent time at other temperatures (from minus 30oC to plus 70oC) and the activation energy can be varied from 15 kcal/mole to 60 kcal/mole.

In order to meet the needs of the perishable industry, JP Labs has also developed freeze, thaw and humidity indicators.