Icelandic fresh fish exporters often use cooling mats to maintain low temperatures in fresh fish products in transport, especially air transport. The cooling mats usually contain either ice or some kind of gel, which necessarily contains such a substance that it can come into contact with the fish if the mat breaks, ie. the contents of the mat are "food-grade".
In foreign markets, the selection of cooling mats in question is wide, but in Iceland the largest sellers of cooling mats for fresh fish Promens Tempra in Hafnarfjörður and Ísgel in Blönduós. Tempra produces ice mats, which only contain water, and Ísgel produces gel mats, and it has been argued that there can be great differences in the cooling capacity of the cooling mats in question. To check this, engineering students Hilmar Arnarson and Sandra Björg Helgadóttir recently studied both the melting point and cooling capacity of ice mats from Tempru and gel mats from Ísgel in the course Fisheries Technology 2 at the University of Iceland.
In the experiment, they placed thermostats inside the cooling mats, which were packed in a foam plastic box. The boxes were placed in the freezer for a few days before standing at room temperature until the cooling mats were fully thawed. The temperature measurements did not reveal a significant difference in either the melting point of the ice and cooling mats (it was approximately 0.0 +/- 0.3 ° C) nor the cooling capacity (the ability of the cooling mats to maintain low food temperatures), see figure 1.
For further information Sigurjón Arason, professor at the University of Iceland and Matís' chief engineer.
Figure 1. Temperature inside ice mats from Promens Tempra and gel mats from Ísgel during thawing.