AUTHOR=Shen Xiaoye , Su Yuan , Hua Zi , Sheng Lina , Mendoza Manoella , He Yang , Green Tonia , Hanrahan Ines , Blakey Rob , Zhu Mei-Jun 

TITLE=Effectiveness of Low-Dose Continuous Gaseous Ozone in Controlling Listeria innocua on Red Delicious Apples During 9-Month Commercial Cold Storage

JOURNAL=Frontiers in Microbiology

VOLUME=12

YEAR=2021

URL=https://www.frontiersin.org/journals/microbiology/articles/10.3389/fmicb.2021.712757

DOI=10.3389/fmicb.2021.712757

ISSN=1664-302X

ABSTRACT=<p>This study aimed to investigate the effects of low-dose continuous ozone gas in controlling <italic>Listeria innocua</italic> and quality attributes and disorders of Red Delicious apples during long-term commercial cold storage. Red Delicious apples were inoculated with a three-strain <italic>L. innocua</italic> cocktail at ∼6.2 log<sub>10</sub> CFU/apple, treated with or without 1-methylcyclopropene, and then subjected to controlled atmosphere (CA) storage with or without continuous gaseous ozone in a commercial facility for 36 weeks. Uninoculated Red Delicious apples subjected to the above storage conditions were used for yeast/mold counts and quality attributes evaluation. The 36 weeks of refrigerated air (RA) or CA storage caused ∼2.2 log<sub>10</sub> CFU/apple reduction of <italic>L. innocua</italic>. Ozone gas application caused an additional &gt; 3 log<sub>10</sub> CFU/apple reduction of <italic>L. innocua</italic> compared to RA and CA storage alone. During the 36-week CA storage, low-dose continuous gaseous ozone application significantly retarded the growth of yeast/mold, delayed apple firmness loss, and had no negative influence on ozone burn, lenticel decay, russet, CO<sub>2</sub> damage, superficial scald, and soft scald of Red Delicious apples compared to CA-alone storage. In summary, the application of continuous low-dose gaseous ozone has the potential to control <italic>Listeria</italic> on Red Delicious apples without negatively influencing apple quality attributes.</p>