A Review: Gaseous Interventions for Listeria monocytogenes Control in Fresh Apple Cold Storage

Abstract

Listeria monocytogenes (L. monocytogenes) causes an estimated 1600 foodborne illnesses and 260 deaths annually in the U.S. These outbreaks are a major concern for the apple industry since fresh produce cannot be treated with thermal technologies for pathogen control before human consumption. Recent caramel apple outbreaks indicate that the current non-thermal sanitizing protocol may not be sufficient for pathogen decontamination. Federal regulations provide guidance to apple processors on sanitizer residue limits, organic production, and good manufacturing practices (GMPs). However, optimal methods to control L. monocytogenes on fresh apples still need to be determined. This review discusses L. monocytogenes outbreaks associated with caramel apples and the pathogen’s persistence in the environment. In addition, this review identifies and analyzes possible sources of contaminant for apples during cold storage and packing. Gaseous interventions are evaluated for their feasibility for L. monocytogenes decontamination on apples. For example, apple cold storage, which requires waterless interventions, may benefit from gaseous antimicrobials like chlorine dioxide (ClO2) and ozone (O3). In order to reduce the contamination risk during cold storage, significant research is still needed to develop effective methods to reduce microbial loads on fresh apples. This requires commercial-scale validation of gaseous interventions and intervention integration to the current existing apple cold storage. Additionally, the impact of the interventions on final apple quality should be taken into consideration. Therefore, this review intends to provide the apple industry suggestions to minimize the contamination risk of L. monocytogenes during cold storage and hence prevent outbreaks and reduce economic losses.

The stress response of Listeria monocytogenes inoculated on fresh apples exposed to gaseous chlorine dioxide

“…It is important to note that ClO 2 did not induce upregulation of hly and clpC expression on apple waxed surfaces, which may provide protection from fumigation chemicals by absorbing oxidative stress through slight lipid peroxidation. reduction for 1 month (Guan et al, 2021;Guan et al, 2023). In addition, there was no significant impact on the quality or antioxidant values of apples fumigated with ClO 2 (Guan et al, 2021(Guan et al, , 2023.…”

“…Listeria monocytogenes ( L. monocytogenes ) is a gram‐positive, facultatively anaerobic, non‐spore‐forming, and intracellular foodborne pathogen that causes listeriosis (Guan et al, 2021). The Centers for Disease Control and Prevention (CDC, 2021) reports that Listeria outbreaks are associated with an estimated 1600 cases of listeriosis and 260 deaths annually in the United States.…”

“…This outbreak affected 35 individuals across 12 states in the United States (CDC, 2014). The ability of L. monocytogenes to replicate at refrigeration temperatures is a concern for the apple industry, which relies on cold storage to provide fresh apples throughout the year (Guan et al, 2021). In fresh apple processing environments, L. monocytogenes is generally exposed to oxidizing sanitizers and disinfectants like chlorine, chlorine dioxide (ClO 2 ), and peroxyacetic acid (Bansal et al, 2018).…”

“…Gaseous ClO 2 treatment effectively inactivates pathogens on surfaces that liquid disinfection may not reach (Du et al, 2002; Du et al, 2003; Guan et al, 2021; Guan et al, 2023; Lee et al, 2006; Park & Kang, 2017; Sy et al, 2005). Previous studies demonstrated the inactivation of L. monocytogenes and spoilage microorganisms (MOs) by gaseous ClO 2 on fresh apples (Du et al, 2002; Guan et al, 2023; Lee et al, 2006; Park & Kang, 2017; Sy et al, 2005).…”

An Innovative Layer-by-Layer Edible Coating to Regulate Oxidative Stress and Ascorbate–Glutathione Cycle in Fresh-Cut Melon

“…Phenolic compounds are widely recognized as the primary compounds involved in the overall antioxidant capacity of fruits and vegetables. Cutting or damaging fruit triggers a cellular response that activates phenolic biosynthesis, enhancing the nutritional value and health-promoting properties [50][51][52]. Different studies have demonstrated a significant TPC increase and antioxidant activity following wounding in several fresh-cut fruits and vegetables [53][54][55][56][57][58][59].…”