Kinetics of quality change of peeled shrimp (Litopenaeus vannamei) by utral-high pressure

Ultra-high pressure is a new non-thermal processing technique of food. For the purpose of mastering the law on the qualities of peeled shrimp at different pressures, the kinetic methods were applied to establish the models for peeled shrimp quality changes during ultra-high pressure and then their dynamic characteristics were studied. Fitting by dynamic equations, the reaction rate constants k and exponential decay time constant D of reaction models for all qualities were determined. Results showed that treatment pressures and time had a significant (p<0.05) effect on the shrimp qualities, such as mass loss, water content, hardness, pH as well as a*value and b* value. Meantime, the changes of the mass loss, water content, hardness, b* value were based on zero-order kinetic model, changes of water content and pH were followed by both zero-order or first-order kinetic model, a* value was met with the first- order kinetic model. Results would provide some helpful information for predicating and controlling qualities of peeled shrimp processed by ultra-high pressure.