The IRI activity in the model system (see section 2.6) was analyzed by comparing the ice crystal morphology and mean ice crystal diameters after 4 h and 72 h in a carrageenan solution to a carrageenan-free control solution. For an initial evaluation of the effect of different cations on the IRI activity, exemplary pictures of the ice crystals obtained after 72 h in solutions prepared with the potassium, calcium, and sodium forms of KC1, IC1, LC1, and LC2 were visually assessed (Fig. ).