Aqueous chlorine dioxide treatment of horticultural produce: Effects on microbial safety and produce quality–A review

Abstract

Microbial load on fresh fruit and vegetables causes decay and losses after harvest and may lead to foodborne illness in case of contamination with human pathogens on raw consumed produces. Washing with tap water only marginally reduces microorganisms attached to produce surfaces. Chlorine is widely used for decontamination on fresh horticultural produces. However, due to harmful by-products and the questionable efficacy it has become increasingly challenged. During the last 20 years, the interest to study ClO treatments as an alternative sanitation agent for industrially prepared fresh produce has largely increased. For a wide range of commodities, the application of gaseous ClO has meanwhile been investigated. In addition, since several years, the interest in aqueous ClO treatments has further risen because of the better manageability in postharvest processing lines compared to gaseous application. This article critically evaluated the effects of postharvest application of aqueous ClO, either alone or in combination with other treatments, on microbial loads for various horticultural produces. In laboratory investigations, application of aqueous ClO at concentrations between 3 and 100 ppm effectively reduced counts of natural or inoculated microorganisms (bacteria, yeasts, and mold) in the range of 1 and 5 log. However, various effects of ClO treatments on produce quality have been described. These mainly comprise implication on sensory and visual attributes. In this context, there is increasing focus on the potential impacts of aqueous ClO on relevant nutritional components of produces such as organic acids or phenolic substances.

Sprouts and Microgreens: Trends, Opportunities, and Horizons for Novel Research

“…The application of 20,000-ppm calcium hypochlorite is likely the most commonly used chemical treatment. However, although recommended by the Food and Drug Administration (FDA), this method carries distinct drawbacks concerning worker safety and environmental impact, difficulty to make organic food claims, disinfection efficacy that may vary in relation to the physical properties of the seed surface (e.g., smooth vs scarified) [128,130], and impact on product quality [138]. Consequently, there is a need for alternative methods that optimally combine disinfection efficacy with safety and environment-friendly features.…”

Integrity of the Escherichia coli O157:H7 Cell Wall and Membranes After Chlorine Dioxide Treatment

“…Additionally, chlorinated washes lack efficacy outside a narrow pH range and can potentially form carcinogenic substances, such as trichloramines, as byproducts of treatment (Richardson et al, 1998;Shen et al, 2016). The use of chlorine dioxide (ClO 2 ) washes as an alternative to conventional chlorinated washes has increased in popularity over the past 20 years due to their high oxidative capacity, stability over a wide pH range, antimicrobial efficacy, and limited toxic byproduct formation (Gómez-López et al, 2009;Wu, 2016;Bridges and Wu, 2018;Praeger et al, 2018;Tadepalli et al, 2018;Sun et al, 2019). Currently, ClO 2 is used for applications such as disinfection of drinking water and wastewater, antimicrobial agent in water used in poultry processing and fruits and vegetables that are not raw agricultural commodities, sterilization of medical surfaces, equipment, and waste, and bleaching in pulp and paper industries (Gómez-López et al, 2009;Praeger et al, 2018).…”

Preparation of Coated Corrugated Box for Controlled-Release of Chlorine Dioxide and Its Application in Strawberry Preservation

“…However, control presented the lowest firmness among all the groups since day 2, which demonstrated that the firmness of strawberries packed in 6 g/L NaClO 2 , and 9 g/L NaClO 2 was better maintained by ClO 2 treatment. The delayed softening of fruit by ClO 2 treatment has been widely reported [3], which was mainly related to the reduced metabolism and inhibited activities of enzymes.…”