# Non-Thermal Methods for Ensuring the Microbiological Quality and Safety of Seafood
## 2 High Hydrostatic Pressure--HHP
### Microbiological Quality and Safety  
There are numerous strategies for the control of pathogens in fish and fishery products. HHP is used in the seafood industry, while it appears to be effective against the most common pathogenic and spoilage bacteria found on seafood products. Microbiological safety has been reported to be assured for many fish and seafood products with higher added value, such as shrimp, salmon, trout, cod, and oysters, among others. Table 1 presents some publications about HHP's application on fish and seafood products, showing targeted microorganisms and pressurization parameters (time, pressure level, and temperature). However, HHP treatment alone is often insufficient for substantial reduction or even inactivation of some microorganisms and needs to combine with other hurdles [46]. \begin{table}
\begin{tabular}{c c c c} \hline \hline
**Products** & **Treatment Conditions** & **Target Microorganisms** & **References** \\ \hline Sea bass (_Diacenturchus labtex_) fillers & 100, 250, and 400 MPa/0, 5, 15, and 30 min/6 \({}^{\circ}\)C & Mesophilic macrobek bacteria & [47] \\ Sea bass (_D. labtex_) fillets & 600 MPa/5 min/25 \({}^{\circ}\)C & _thermoplastic_, yeasts and models, _Enter \begin{tabular}{c c c} \hline
**Products** & **Treatment Conditions** & **Target Microorganismss** & **References** \\ \hline  & 250 MPa/s min, 300 MPa/s min, and & \\  & 350 MPa/1 min/\(-\)2, 1.5, 10, 20, 30, 40, and 45 \({}^{\circ}\)C & \\  & 5-log reduction parameters: 250, 300, 350, 400, and & \\  & 450 MPa/2 min/1, 20, 30, and 40 \({}^{\circ}\)C & \\  & Whole Gold Band Obsers *** & 250 to 400 MPa/s 1 to 3 min/Room temperature & Total aerobic bacterial counts, presumptive Virio spp, count (PV), \\  & & and presumptive \(V\). _vululnfus_ count (PVv) & [59] \\  & Coked oysters (C. _gigus_) & 250 MPa/2, 5, 8, and 10 min/40 \({}^{\circ}\)C & Total aerobic counts, total anaerobic counts, and Coliforms \\  & & \\ \multicolumn{3}{l}{Four types of shells:} & \\ \multicolumn{3}{l}{-} & \multicolumn{1}{l}{Musels (_Metilus chalis_)} & \\ \multicolumn{3}{l}{-} & \multicolumn{1}{l}{Dublin by prayens (_Neptropes noviecs_)} & \\ \multicolumn{3}{l}{-} & \multicolumn{1}{l}{Sollers (_Pectin maximants_)} & \\ \multicolumn{3}{l}{-} & \multicolumn{1}{l}{Oysters (C. _gigus_)} & \\ \multicolumn{3}{l}{-} & \multicolumn{1}{l}{Oysters (C. _gigus_)} & \\ \multicolumn{3}{l}{-} & \multicolumn{1}{l}{Sisc species of fresh edible seaweeds:} & \\ \multicolumn{3}{l}{-} & \multicolumn{1}{l}{Two chlorophyta (_Calain fugile_ and _Uliva latico_)} & \\ \multicolumn{3}{l}{-} & \multicolumn{1}{l}{Three chlorophyta (_Himuthalia clogenta_, _Laminaria Ortho/c_, and _Uliva latico_)} & \\ \multicolumn{3}{l}{-} & \multicolumn{1}{l}{One Rhodophyta (_Chandra viruspis_)} & \\ \multicolumn{3}{l}{-} & \multicolumn{1}{l}{Pacific osysters (C. _gigus_)} & 300 MPa/2 min/20 \({}^{\circ}\)C & Total viable counts and heterotrophic marine bacteria & [63] \\ \hline \end{tabular}   
\({}^{*}\)On min\({}^{*}\) pressure holding time refers to pressurization and immediate depressurization, \({}^{*}\)Smoked salmon mixed used as a sample after thawing at 20 \({}^{\circ}\)C for 15 min. The temperature of the sample was about 7 \({}^{\circ}\)C. \({}^{*}\)Smoked salmon mixed used frozen at \(-\)29 \({}^{\circ}\)C. *** A commercially available HP-tested product. Microbial growth and activity are important indexes to determine the shelf life and safety of various fresh and lightly preserved RTE seafood [64]. Therefore, HHP treatment was adopted to extend these products' shelf life by reducing the total aerobic bacterial counts attributed to the products' spoilage [65; 66]. [PERSON] et al.