Optimization of microbial inactivation of shrimp by dense phase carbon dioxide

Microbial inactivation of Litopenaeus vannamei by dense phase carbon dioxide (DPCD) treatment was investigated and neural network was used to optimize the process parameters of microbial inactivation. The results showed that DPCD treatment had a remarkable bactericidal effect on microorganism of shrimp. A 3 × 5 × 2 three-layer neural network model was established. According to the neural network model, the inactivation effect was enhanced with pressure, temperature and exposure time increasing and temperature was the most important factor affecting microbial inactivation of shrimp. Cooked appearance of shrimp by DPCD treatment was observed and seemed to be more positively acceptable by Chinese diet custom. Therefore, color change of shrimp by DPCD treatment could have a positive effect on quality attributes. Moderate temperature 55 °C with 15 MPa for 26 min treatment time achieved a 3.5-log reduction of total aerobic plate counts (TPC). The parameters combination might be appropriate for shrimp process by DPCD.

► DPCD treatment had a remarkable bactericidal effect on microorganism of shrimp.
► Temperature was the most important factor affecting microbial inactivation of shrimp.
► Cooked appearance of shrimp could have a positive effect on quality attributes.
► DPCD treatment of 55 °C with 15 MPa for 26 min achieved a 3.5-log reduction of TPC.