Cryoprotective Effects of Some Materials on Cod‐Surimi Proteins during Frozen Storage

Freeze‐induced protein denaturation of cod surimi was studied as affected by carbohydrates (sucrose and glucose syrup at 8% w/w), polyols, (sorbitol and glycerol at 8% w/w), protein hydrolysates (fish protein and casein hydrolysates at 4% w/w), hydrocolloids (pectin‐1% w/w, sodium alginate, lambda‐ and iota‐carrageenan‐0.5% w/w) and combinations of the above, (sucrose/sorbitol 1:1 mixture at 8% w/w, or combined with protein hydrolysates at 4% w/w). Salt extract‐able protein (SEP) and heat induced denaturation by differential by differential scanning calorimetry (DSC) were used to monitor protein changes in surimi stored 16 wk at ‐20°C. The best cryoprotection effect was achieved from sorbitol, glucose syrup (DE = 60), sucrose and sucrose/sorbitol 1:1 w/w mixture at 8% w/w in surimi. Correlations between certain DSC parameters and SEP were high.