Gelation properties of fatty fish processed with or without added sodium chloride, cryoprotectants and antioxidants

Abstract

The effect of 3% (w/w) added salt; an antioxidant mixture consisting of 0·02% (w/w) t-butylhydroquinone (TBHQ) (based on total lipid), 0·2% (w/w) ascorbate and 0·2% (w/w) sodium tripolyphosphate (STPP) added during the grinding and washing steps; and a cryoprotectant mixture of 4% (w/w) sorbitol, 4% (w/w) sucrose, and 0·2% (w/w) STPP added just prior to gel formation were tested for their effects on true strain and stress at breakage and fold test scores of washed bluefish and mackerel mince. The addition of 3% (w/w) NaCl and the cryoprotectant mixture increased true strain values under all conditions; fold test scores followed similar patterns. The antioxidant mixture gave increased strain values in the absence of the added 3% (w/w) NaCl in both bluefish and mackerel prepared with or without cryoprotectants; in the case of mackerel, the antioxidant mixture gave higher true strain values in the presence of salt as well. Stress values were highly variable and no clear trends were observed with bluefish with any of the parameters; seven out of eight samples of mackerel had lower stress values in the presence of the antioxidant mixture. The results may be useful in designing a process for improving the gelation characteristics of fatty fish.