Single- and multi-cycle high hydrostatic pressure treatment on microbiological quality of mud snail (Bullacta exarata) during refrigerated storage

• The B. exarata is a resource of antioxidant and functional shellfish in China.
• Effects of single- and multi-cycle HHP treatment on microbiology quality during refrigerated storage were evaluated.
• The modified Gompertz model was chosen to predict the effects of multi-cycle HHP.
• Multi-cycle HHP (B + F) method could improve the shelf-life of B. exarata for 38 days.
• The results could provide an effective method on food processing conditions.

High hydrostatic pressure (HHP) processing is an industrial technology used for preservation of a wide range of food products, and vacumm-packed mud snails (Bullacta exarata) were HHP processed to ensure food safety and shelf-life stability. The effects of single- and multi-cycle HHP treatment, especially the combination of different intensities, on the microbial behavior and shelf-life extension of B. exarata during subsequent storage were investigated. Total microbial count, psychrophilic microorganisms, Clostridium bacteria, total Enterobacteriaceae and H2S-producing bacteria were enumerated during subsequent refrigerated storage, and Gompertz model was chosen to predict the shelf-life, growth rate, lag time and generation time. The results showed that the initial microbial load was obviously reduced as the pressure increased. Total Enterobacteriaceae and H2S-producing bacteria were not detected in multi-cycle HHP processing during refrigerated storage. Moreover, multi-cycle HHP method (B + F) could improve the shelf-life of B. exarata for more than 38 days. The model indicated that the lag time for Clostridium bacteria processed with multi-cycle HHP (B + F) was extended to 24.65 days. Our findings will be of aid for the establishment of general process guidelines, and demonstrated that multi-cycle HHP technology has potential for application in mud snail preservation and processing.