Shrimp treated with ASS + 3% MSG (pH 11.5) had reduced drip loss and no AG and NAG activities were detected when subjected to repeated freeze–thawing.
Shear force of both of raw and cooked shrimp with all treatments increased when
freeze–thaw cycles increased up to 3 cycles, but a drastic decrease was found after 5 freeze–thaw cycles.
Freeze–thawing caused protein denaturation, tissue disruption and damage of muscle fiber as indicated by the release of AG and NAG.
Soaking shrimp with 0.75% NaOH containing 2.5% NaCl and 3% MSG was able to reduce quality changes induced by freeze–thawing process.