Aqueous ozone is widely used in the food industry as a potent, residue-free disinfectant for washing produce, sanitizing equipment, and treating processing water. Its effectiveness is supported by numerous scientific studies and regulatory approvals from bodies like the U.S. FDA, which has granted it "Generally Recognized As Safe" (GRAS) status for direct food contact.
How Aqueous Ozone Is Used in Food Industries
Aqueous ozone is applied in various ways within food processing facilities.
- Washing Fruits and Vegetables: Products are often washed or rinsed in ozonated water to kill pathogens and spoilage microorganisms on their surface. This application can also help remove pesticide residues.
- Sanitizing Food-Contact Surfaces and Equipment: Ozone water is used for disinfecting processing lines, cutting tables, conveyors, and utensils, as it leaves no residues and is effective against microbiome.
- Processing Water Treatment: It is used to decontaminate and improve the reusability of processing water, which helps conserve water and lowers the chemical demand of wastewater discharge.
- Meat, Poultry, and Seafood Processing: Aqueous ozone is applied to meat and fish to reduce bacterial counts and extend shelf life without affecting sensory qualities when used at appropriate concentrations.
Evidence Supporting its Use
The use of aqueous ozone is supported by a strong body of scientific evidence and regulatory milestones:
- GRAS Status: The most significant evidence of its safety and efficacy is its Generally Recognized As Safe (GRAS) status granted by a panel of experts in 1997, and subsequently approved by the U.S. Food and Drug Administration (FDA) in 2001 for use as an antimicrobial agent on all foods, including meat and poultry products.
- Potent Antimicrobial Action: Studies demonstrate that ozone is a much stronger oxidizing agent than traditional disinfectants like chlorine (2.07 V oxidation potential compared to chlorine's 1.36 V). This allows it to inactivate a broad spectrum of microorganisms, including E. coli O157:H7, Salmonella, Listeria monocytogenes, as well as various fungi, yeasts, and viruses, often more rapidly and effectively than chemical alternatives.
- Residue-Free Decomposition: A major advantage highlighted in research is that ozone naturally and rapidly decomposes into ordinary oxygen, leaving no harmful chemical residues, taste, or odour on the treated food or surfaces.
- Extended Shelf Life: Numerous studies show that aqueous ozone treatments can significantly reduce spoilage microorganisms, thereby extending the freshness and visual quality of perishable items like fresh-cut lettuce, cabbage, and various fruits during storage.
- Independent Study Results: Specific research has shown tangible results, such as a 1 to 2.4 log reduction of L. monocytogenes on ready-to-eat meats, and a greater than 3 log reduction of various pathogens on produce like tomatoes.
While effectiveness can vary based on factors like product surface roughness, ozone concentration, and contact time, a large body of evidence confirms its role as an effective, environmentally friendly, and safe food processing aid.
References
1. Food Safety Authority. Application of ozone for enhancing the microbiological safety and quality of foods: a review. Journal of Food Protection. – Demonstrates ozone’s antimicrobial mechanism and GRAS reaffirmation. https://pubmed.ncbi.nlm.nih.gov/10492485/
2. Efficacy of aqueous ozone for decontamination of E. coli O157:H7 and Salmonella on berries. PubMed – Provides quantified log reductions on produce. https://pubmed.ncbi.nlm.nih.gov/17536665/
3. MLA Aqueous Ozone report – Details regulatory acceptance and application on food processing equipment and meats. https://www.mla.com.au/globalassets/mla-corporate/research-and-development/program-areas/food-safety/documents/food-safety-finished-product-intervention/aqueous-ozone.pdf
4. Effects of aqueous ozone on microbial load and shelf life of fresh-cut apples. International Journal of Food Science & Technology – Shows extended shelf life benefits. https://academic.oup.com/ijfst/article/51/5/1099/7774680
5. A Review into the Effectiveness of Ozone Technology for Improving the Safety and Preserving the Quality of Fresh-Cut Fruits and Vegetables. https://pubmed.ncbi.nlm.nih.gov/33915979/
6. Letters in Applied Microbiology review – Summarizes reductions of pathogens and spoilage organisms on produce and surfaces.
