Effect of Chlorine Dioxide Treatment and Storage in a Modified Atmosphere on the Inactivation of Cronobacter spp. on Radish Seeds

Conventional and non-conventional disinfection methods to prevent microbial contamination in minimally processed fruits and vegetables

Pandemic COVID-19 warned the importance of preparing the immune system to prevent diseases. Therefore, consuming fresh fruits and vegetables is essential for a healthy and balanced diet due to their diverse compositions of vitamins, minerals, fiber, and bioactive compounds. However, these fresh products grew close to manure and irrigation water and are harvested with equipment or by hand, representing a high risk of microbial, physical, and chemical contamination. The handling of fruits and vegetables exposed them to various wet surfaces of equipment and utensils, an ideal environment for biofilm formation and a potential risk for microbial contamination and foodborne illnesses. In this sense, this review presents an overview of the main problems associated with microbial contamination and the several chemicals, physical, and biological disinfection methods concerning their ability to avoid food contamination. This work has discussed using chemical products such as chlorine compounds, peroxyacetic acid, and quaternary ammonium compounds. Moreover, newer techniques including ozone, electrolyzed water, ultraviolet light, ultrasound, high hydrostatic pressure, cold plasma technology, and microbial surfactants have also been illustrated here. Finally, future trends in disinfection with a sustainable approach such as combined methods were also described. Therefore, the fruit and vegetable industries can be informed about their main microbial risks to establish optimal and efficient procedures to ensure food safety.

Chloroxyanion Residue on Seeds and Sprouts after Chlorine Dioxide Sanitation of Alfalfa Seed

The effects of a 6-h chlorine dioxide sanitation of alfalfa seed (0, 50, 100, and 200 mg/kg seed) on total coliform bacteria, seed germination, and the presence of chlorate and perchlorate residues in seed rinse, seed soak, and alfalfa sprouts was determined. Chlorate residues in 20,000 mg/L calcium hypochlorite, commonly used to disinfect seed, were quantified. Chlorine dioxide treatment reduced (P < 0.05) total coliforms on seeds with no effect (P > 0.05) on germination. Dose-dependent sodium chlorate residues were present in seed rinse (4.1 to 31.2 μg/g seed) and soak (0.7 to 8.3 μg/g seed) waters, whereas chlorate residues were absent (LOQ 5 ng/g) in sprouts, except for 2 of 5 replicates from the high chlorine dioxide treatment. Copious chlorate residues were present (168 to 1260 mg/L) in freshly prepared 20,000 mg/L calcium hypochlorite solution, and storage at room temperature increased chlorate residues significantly (P < 0.01).