Assessment of the efficacy of decontamination treatments against Salmonella enterica subsp. enterica serovar Thompson on strawberries at different storage conditions

Abstract

The risk of outbreaks associated with strawberries consumption has led to the evaluation of different antimicrobial strategies. The effect of disinfectants, i.e. chlorine (100 and 200 mg L−1), peracetic acid (40 and 80 mg L−1), lactic acid and hydrogen peroxide (2.5 and 5%), on strawberries contaminated with Salmonella enterica subsp. enterica serovar Thompson during 2 min and stored at different times at two temperatures (20 and 4 °C) was studied. Likewise, the influence of disinfectants on the physicochemical quality of fruits was addressed. The efficacy of 100 mg L−1 chlorine or 40 mg L−1 peracetic acid decreased as storage time at 20 °C increased. Most of the physicochemical parameters were not affected by the treatments, except for 5% hydrogen peroxide, which caused discoloration of the strawberries. 2.5% lactic acid treatment was selected for the evaluation of its antimicrobial effect on strawberries stored at 4 °C for 6 d after treatment. This treatment achieved an efficient reduction of S. Thompson which was maintained over time, while for the case of mesophilic bacteria and yeasts and molds, differences with control or water-washed samples were levelled out over time. No changes in physicochemical parameters were observed during the storage time. 2.5% lactic acid is proposed for decontamination of strawberry-derived products.