Effect of electrical conductivity on the inactivation of Anisakis spp. by PEF

Pulsed Electric Fields (PEF) have proven effective in inactivating Anisakis in fish fillets. One of the parameters conditioning the lethal efficacy of PEF is the electrical conductivity of the treatment medium in which the fish is immersed. However, the underlying cause of this increased efficacy remains unknown. It was hypothesized that the difference in electrical conductivity between fish cells and Anisakis larvae could influence the electric field applied to each cell type. As measuring cells’ electric fields is difficult, the study adopted an alternative dual approach. First, based on the experimental data, a mathematical equation was developed to predict Anisakis inactivation in hake belly fillets within the study’s parameter ranges (1–5 kV/cm, 10–40 kJ/kg, 7–30 μs pulse width, and 0.4–10 mS/cm). Additionally, an increase in electrical conductivity under the same PEF treatment was experimentally observed to result in a greater degree of parasite inactivation. To investigate this phenomenon, the numerical simulation strategy was employed to estimate the electric field strength affecting the elements in the treatment chamber. The results showed that as the electrical conductivity of the medium increased, the electric field strength in the parasite also increased, thus explaining the greater inactivation observed. • Electrical conductivity of the treatment medium influences Anisakis inactivation. • Increasing medium electrical conductivity enhances Anisakis larvae inactivation. • Numerical simulations confirm conductivity’s key role in PEF treatment efficacy. • A predictive equation for Anisakis inactivation was developed.