Quality parameters of sea bass subjected to pulsed electric field (PEF) treatment and brine salting

Salting is one of the oldest preservation methods applied to muscle foods such as fish and meat. In the present study, sea bass samples were subjected to PEF pre-treatment prior to brine salting to verify the possible acceleration of the brining rate, increasing the salt uptake and ensuring the homogeneous salt distribution in the muscle. The applied intensity of the current was set at 10 and 20 A (corresponding to a field strength of 0.3 and 0.6 kV/cm) prior to sea bass salting in brine with 5 and 10% salt concentration, respectively. The results have shown that PEF pretreatment could effectively shorten the brine salting time compared to control samples (from 5 to 2 days), or increase the salt uptake up to 77%, ensuring at the same time its homogenous distribution in the muscle. However, myofibrillar protein solubility was significantly reduced in PEF pretreated samples. At the same time, no significant differences in water holding capacity and water activity between PEF pre-treated and untreated samples were found during the whole salting period. Freezable water was influenced by PEF application, but the effect was significant only at the lowest salt concentration during the first period of the salting process. PEF-treated fish samples also showed a significant increase in total protein carbonyls on day 5 and day 8 of brine salting as electroporation effect on protein oxidation. PEF treatment led to a significant (p<0.05) increase in primary and secondary lipid oxidation products compared to untreated ones. However, none of the fish samples treated at the higher current intensity of 20 A exceeded the acceptable level for peroxide value of 5 meq active oxygen/kg lipid according to the requirements of the Standard for fish oils CODEX STAN 329-2017.