The Effect of Controlled-release Chlorine Dioxide on the Preservation of Grapefruit

Abstract

<jats:p>The effect of controlled-release chlorine dioxide (ClO<jats:sub>2</jats:sub>) gas on the safety and quality of grapefruit was studied. The experiments were run under controlled chamber systems with inoculated fruit, and in boxed fruit under commercial conditions. For the inoculation test, fruit artificially inoculated with either <jats:italic>Escherichia coli</jats:italic> or <jats:italic>Penicillium digitatum</jats:italic>, or naturally inoculated <jats:bold><jats:italic>Xanthomonas citri</jats:italic></jats:bold> ssp. <jats:bold><jats:italic>citri</jats:italic> (<jats:italic>Xcc</jats:italic>) (fruits with citrus canker lesions), were incubated in a chamber containing a dose equivalent to 0–60 mg·L<jats:sup>−1</jats:sup> of pure ClO<jats:sub>2</jats:sub> as an antimicrobial agent. After 24 hours, the microbial population on treated grapefruit was significantly reduced compared with that of control fruit: a dosage of 5 mg·L<jats:sup>−1</jats:sup> completely inhibit the growth of <jats:italic>E. coli</jats:italic> and <jats:italic>P. digitatum</jats:italic>, but a dosage of 60 mg·L<jats:sup>−1</jats:sup> was needed to completely kill <jats:italic>Xcc</jats:italic>. For the simulated commercial experiment, fruit were harvested in late Oct. 2015 passed through a commercial packing line, and packed in 29 L citrus boxes. ClO<jats:sub>2</jats:sub> packets were attached to the top lids with the following five treatments: fast-release, slow-release, slow/fast-release combination (each containing 14.5 mg·L<jats:sup>−1</jats:sup> of pure ClO<jats:sub>2</jats:sub>), double dose fast-release (containing 29 mg·L<jats:sup>−1</jats:sup> of ClO<jats:sub>2</jats:sub>), and control. After 6 weeks of storage at 10 °C (to simulate storage and transportation) + 1 week of storage at 20 °C (to simulate retail marketing), the fruit quality was evaluated. The slow-release treatment at standard dose exhibited the best antimicrobial activity, reducing total aerobic bacterial count and yeast/mold count by 0.95 and 0.94 log colony-forming units (cfu)/g of fruit, respectively, and maintained the best visual, sensory, and overall quality. However, the higher dosage treatments resulted in phytotoxicity as evidenced by peel browning.</jats:bold></jats:p>

Fresh Produce Safety and Quality: Chlorine Dioxide’s Role

“…Moreover, strawberries packed with ClO 2 -generating pads exhibited reduced growth of yeast and molds until 8 days of their 12 days-storage period at 2°C ( Chiabrando et al, 2018 ). Similarly, ClO 2 treatment reduced total aerobic bacterial and yeast and mold counts by 0.95 and 0.94 log, respectively, in grape fruit after 6 weeks of storage at 10°C ( Sun et al, 2017a ).…”

“…Reports suggest that ClO 2 treatment is more effective against E. coli inoculated on smooth non-stem-scar surfaces than on rough stem-scar areas ( Pao and Davis, 1999 ). Additionally, X. citri on grapefruit surface requires a higher ClO 2 concentration for complete inactivation than E. coli ( Sun et al, 2017a ).…”

“…By contrast, ClO 2 treatment may also cause browning of fresh produce. For example, ClO 2 treatment resulted in rapid color change in spinach leaves, browning of grapefruit, cabbage, lettuce, peaches, and apples ( Sy et al, 2005b ; Lee et al, 2006 ; Mahmoud and Linton, 2008 ; Park and Kang, 2015a ; Sun et al, 2017a ).…”

Chlorine Dioxide Generation Method and Its Action Mechanism for Removing Harmful Substances and Maintaining Quality Attributes of Agricultural Products

“…For example, Remorini et al (2015) reported that treatment with 100 mg L −1 ClO 2 combined with 3% ascorbic acid (AA) significantly slowed the browning of fresh-cut apples of two cultivars ('Red Delicious' and 'Granny Smith') at 4°C for 96 h, and this treatment had better effects on 'Red Delicious' than 'Granny Smith'. Sun et al (2017b) studied the effects of ClO 2 gas on the grapefruit quality during storage and found that 5 mg L −1 pure ClO 2 completely inhibited the growth of E. coli and P. digitatum inoculated on grapefruit, and treatment with up to 60 mg L −1 of ClO 2 absolutely inactivated Xanthomonas citri ssp. citri (Xcc) that causes the canker lesion of citrus fruit.…”

The Potential Application of Nanoparticles on Grains during Storage: Part 1 – An Overview of Inhibition against Fungi and Mycotoxin Biosynthesis

“…Chlorine dioxide (ClO 2 ) has biocidal activities due to its oxidizing capacity (strong oxidant), and is widely used for decontamination. It is used both in its gaseous and aqueous forms to sanitize food and, exert potent biocidal activity against bacteria, yeasts, and molds [129][130][131][132][133]. All bacteria and their spores in a hospital room were reported killed/inactivate by ClO 2 gas [134].…”