CRYOPROTECTIVE EFFECTS OF TREHALOSE ON GRASS CARP (CTENOPHARYNGODON IDELLUS) SURIMI DURING FROZEN STORAGE

The cryoprotective effects of sucrose (4%)/sorbitol (4%)/polyphosphate (0.3%, composed of sodium pyrophosphate, sodium tripolyphosphate and sodium hexametaphosphate at a ratio of 2: 2: 1), sucrose (4%)/sorbitol (4%), trehalose (6%) and trehalose (6%)/polyphosphate (0.3%) on grass carp surimi protein during frozen storage at -18C for up to 25 weeks were investigated. All cryoprotectants were proved to be effective at alleviating protein denaturation by the lower decrease in salt extractable protein (SEP) content, Ca(2+)-ATPase activity, total sulfhydryl content as well as gel-forming ability comparied with the control. Especially, trehalose (6%)/polyphosphate (0.3%) showed the greatest protective effect on protein. Cryoprotective effect of trehalose (6%) was better than that of sucrose (4%)/sorbitol (4%), but not as good as that of sucrose (4%)/sorbitol (4%)/polyphosphate (0.3%).