Abstract: Penaeus vannamei meat with and without the addition of 5% (m/m) maltodextrin (PV-MD and PV) at various moisture contents (6.5%, 18.0% and 76.5%) were stored at four different temperatures (–78, –35, –18 and 5 ℃) to explore the mechanisms of quality changes and to improve the storage stability of Penaeus vannamei meat. The changes of Ca2+-ATPase activity with the above variables were analyzed and the kinetic model was established. The results showed that at the same moisture content, Ca2+-ATPase activity of Penaeus vannamei decreased with increasing temperature. Similarly, at the same storage temperature, Ca2+-ATPase activity of Penaeus vannamei decreased with increasing moisture. The rate of decrease in Ca2+-ATPase activity in PV-MD was lower than that in PV. During storage, the change of Ca2+-ATPase activity followed the second-order reaction kinetic model 1/C ? 1/C0 = kt. The reaction rate constant k increased with increasing temperature and moisture content, whereas k decreased with the addition of maltodextrin. This implies that the addition of maltodextrin to Penaeus vannamei meat can alleviate reaction rate and protein denaturation degree. During freezing and/or frozen storage of Penaeus vannamei, protein denaturation rate and degree was mainly affected by glass transition. But they were influenced by both water activity and glass transition during storage at 5 ℃.

Key words: Penaeus vannamei, Ca2+-ATPase activity, protein denaturation, kinetic modeling, glass transition theory