Poly-Chill fluid is authorized by USDA for use in Federally inspected meat and poultry plants. Poly-Chill fluid is a viscous, stable, hygroscopic liquid which is completely miscible with water. It is formulated with USP grade propylene glycol and inhibited with food-grade dipotassium phosphate to prevent corrosion.
Aqueous solutions are widely used in the immersion freezing of plastic-wrapped poultry. The freezing bath temperature is generally maintained at -18C (0F) to freeze the poultry to a depth of 3/8 to 1/2 inch in 30 minutes. Freezing of the poultry is completed in a freezing room as a separate operation.
Food products such as fish, meat and vegetables are normally frozen by exposure to high velocity air that is prechilled by contact with cooling coils. Poly-Chill fluid is continuously sprayed over the coils to prevent formation of frost or ice that would otherwise result from condensation of moisture from the air. The resulting diluted glycol can be reconcentrated for reuse.
As solar technology has developed, aqueous solutions of propylene glycol have received wide acceptance as a heat-transfer fluid in areas where freezing is a problem. The aqueous glycol solutions provide freeze protection. In this application, the use of Poly-Chill fluid is particularly advantageous in that the inhibitor provides corrosion protection. The inhibitor concentration must be monitored periodically to ensure corrosion protection.