Chlorine dioxide wash of shrimp and crawfish an alternative to aqueous chlorine

This study compared the biocidal effect of chlorine dioxide spray with traditional chlorine wash on shrimp and crawfish tail meat. Treatments included aqueous chlorine (hypochlorite) (10–40 mg l−1) and chlorine dioxide (10–40) mg l−1 combined with and without a high-pressure prewash (600 psi). Standard aerobic and psychrotrophic bacteria were evaluated for up to 21 days. Samples treated with chlorine dioxide in both treatment techniques had lower aerobic and psychrotrophic counts (P<0·001) than any combination of other treatments tested. Reductions were from 1 to 4 log10 (increasing as initial concentration of chlorine dioxide increased). Pressure application increased the effectiveness of both sanitizers and water wash by at least 0·5 log. Chlorine residuals of 18–51 mg g−1 were present in aqueous chlorine treatment of \ge30 ppm. No chlorine residuals were present following chlorine dioxide treatments.