Cryoprotectants Preserve Quality of Restructured Trout Products Following Freeze–thaw Cycling

The cryoprotective action of 8% sucrose/sorbitol, 8% trehalose, 8% trehalose/sorbitol and 2% sodium lactate was measured in restructured trout products after 1, 3, 5, 10 and 15 freeze–thaw (FT) cycles (–20C; 8 h and 3C; 16 h). Sucrose/sorbitol, trehalose and trehalose/sorbitol minimized thaw loss and toughening of restructured products following FT cycling. Trehalose and trehalose/sorbitol have the potential to replace sucrose/sorbitol. Products containing sodium lactate were firmer and tougher, especially after three FT cycles, and this effect suggests that sodium lactate cannot be substituted for sucrose/sorbitol to stabilize protein denaturation that results from repeated freezing and thawing. Sodium lactate reduced bacterial growth and lipid oxidation, and it did not affect color of raw, restructured products.