Synergistic effect of sodium hypochlorite and ultrasound bath in the decontamination of fresh arugulas

Sanitization is a critical step for the reduction of microbial contaminants in fruits and vegetables in an effort to lessen the occurrence of foodborne diseases. The efficiency of different chemical compounds, either individually or combined with ultrasound treatment, in decontaminating fresh arugulas was evaluated here. The main physicochemical properties and the natural microbiota of arugulas were evaluated after sanitization for 5 min at 25 degrees C. The synergistic effect of ultrasound and sodium hypochlorite led to the best outcome. Ultrasound treatment improved the bactericidal effect of sodium hypochlorite (100 mg/L), leading to a reduction of 1.46 log cycles in relation to the non-sanitized samples, whereas sodium hypochlorite itself provided a 0.85 log cycle reduction. This synergism is due to the ability of ultrasound-induced cavitation to form oxidizing free radicals (e.g., OH and Cl), in addition to its mechanical energy input that facilitates the permeation of hypochlorous acid molecules into microbial cells. It is noteworthy that this mechanical action also favors the removal of microbial biofilms and cell disintegration. The residual chlorine content was lower than that recommended by the current legislation for public water supply. The combined action did not significantly alter the physicochemical and colorimetric properties of the arugulas. Therefore, this sanitization protocol denotes a promising alternative for the decontamination of fruits and vegetables in the food industry and in food processing facilities. Practical applicationsCurrently, there has been an increase in the demand for fresh food as well as an increase in the number of food outbreaks involving these products. In this context, to reduce microbial contamination, this research presents an alternative sanitization method that can be easily used in food processing units for decontamination of vegetables, increasing the microbiological safety of the final product to the consumer.