In this study PMA–0.5% Triton pretreatment was quite effective in vegetable concentrates, but not in shellfish concentrates. This result indicates that PMA is capable of binding the RNA of the thermally inactivated HAV present in vegetable samples and it partially prevents amplification without interferences of the food matrix. For shellfish concentrates, the high turbidity of the sample may avoid the action of PMA pretreatment and this effect was reverted by diluting shellfish concentrates. The interferences of turbidity on viability PCR has also been described for Vibrio parahaemolyticus in raw seafood. This study showed that PMA treatment with turbidities greater than 10 NTU did not adequately inhibit the amplification of DNA (Zhu et al., 2012). Turbid samples containing suspended solids lowered the effective dye concentration by chemical adsorption with organic and inorganic compounds, resulting in decreased effectiveness of the viability treatment (Fittipaldi et al., 2012).