“FREEZE INDICATOR”
Institute of Food Technologists Annual Meeting and Food Exposition, Chicago, IL
July 12th -- 16th 2003

http://ift.confex.com/ift/2003/techprogram/paper_14841.htm
Slide Presentation of Label Size Color Changing Freeze Indicators

“Label Size Color Changing Freeze Indicator”
G. N. PATEL
JP Laboratories Inc.
120 Wood Ave.
Middlesex, NJ 08846

There is a need for monitoring freezing of certain freeze sensitive products, such as fresh blood, vaccines, fresh produce and flowers to determine if the product has been subjected to a freezing temperature and thus damaged. Freeze devices based on rupture of a capsule containing water, dye, surfactant and nucleating agent are available commercially. This type of devices are large, complex, difficult to manufacture, and expensive. There is a need for a device, which is simple, small, easy to make/use and economical. JP labs have developed such a freeze indicator.

The device is composed of (1) a partially polymerized diacetylene, (2) a polymeric gel and (3) a solvent, e.g., ethylene glycol diacetate. When the temperature of the device is lowered below the freezing point of water, ethylene glycol diacetate phase separates out of the mixture and induces an irreversible color change, e.g., blue-to-red, in the diacetylene. Varying the ratio of water to ethylene glycol diacetate and concentration of the polymer varies the temperature and time required for the color change. The device is small (e.g., 1x1x0.2 cm3), changes color at a pre-determined temperature ranging from 0 to -30oC and the time required for the color change is varied from a few minutes to several hours.

Session 54, Intelligent packaing 2:30 PM - 5:30 PM, Monday PM
2003 IFT Annual Meeting - Chicago

Slide Presentation of Label Size Color Changing Freeze Indicators