Fresh fruit and vegetable wash steps do more than remove soil. They are a critical control point for reducing microbial loads and managing cross-contamination in flumes, dunk tanks, and spray systems—especially in high-throughput fresh-cut operations.
Our technology gaining traction in industrial produce packing and processing is aqueous ozone: ozone (O₃) generated on-site, dissolved into wash water, and applied in controlled conditions. When engineered correctly, it can help processors lower microbial counts and support shelf-life by reducing spoilage pressure—while avoiding the storage and handling burdens of many conventional sanitizers.
Why wash water is a solution?
- Act quickly in dynamic, high-load environments
- Help control recirculated wash loops
- Fit within GMP/HACCP programs without introducing problematic residues or byproducts
What ozone does well in produce washing?
Ozone is a high-strength oxidant. In water, it reacts with microbial cell envelopes and key cellular components, disrupting microorganisms and reducing viable counts. In practice, aqueous ozone is used to:
- Reduce microbial loads on produce surfaces (pathogen and spoilage organisms, depending on conditions)
- Control wash water bioburden, helping limit cross-contamination risk in recirculating systems
- Support shelf-life by lowering initial spoilage pressure—often most noticeable on fresh-cut products where microbial growth drives quality loss.
Peer-reviewed reviews consistently describe ozone as a promising decontamination tool for fresh produce, while emphasizing that outcomes vary by commodity, surface roughness, organic load, temperature, and treatment conditions.
Where aqueous ozone fits on a typical line
Common industrial integration points include:
- Pre-wash / primary wash (gross soil reduction + initial microbial knockdown)
- Final rinse (quality-focused step where residue concerns matter most)
- Flume or dunk systems with recirculation (bioburden control in the loop)
- Spray bars / spray tunnels (less dilution, more targeted application)
In many plants, ozone is used as a standalone sanitizer or as part of a multi-hurdle program alongside filtration, water refresh strategy, and hygiene design.
Engineering: performance depends on mass transfer and control
For produce washing, “more ozone” is rarely the right answer. Consistent results come from getting ozone into the water efficiently and holding stable process conditions.
Key design elements:
1) Stable ozone generation (industrial duty cycle)
Industrial systems typically generate ozone from oxygen (often via oxygen concentrators or liquid oxygen feed), then modulate output to match demand.
2) Efficient dissolution and contacting
Ozone must be transferred into water (e.g., venturi injection + static mixing + contact tank, or fine-bubble diffusion systems). The goal is consistent dissolved ozone in the wash zone—not peaks and troughs.
3) Real-time monitoring
Processors commonly control to dissolved ozone and/or ORP (oxidation-reduction potential), with alarms and interlocks. Monitoring is essential because organic load can consume ozone rapidly.
4) Off-gas management
Any degassed ozone should be captured and routed to an ozone destructor (catalytic or thermal), protecting operators and preventing nuisance odors.
Shelf-life benefits: what to expect?
When ozone washing reduces initial spoilage organisms and limits microbial carryover in water, the downstream effect can be slower microbial growth during storage, which supports shelf-life and reduces waste. Reviews on ozone in fresh vegetables and food decontamination describe these shelf-life and quality linkages while noting that results are commodity-specific and must be validated.
Important nuance for produce:
- Surface matters: smooth skins respond differently than rough, porous, or cut surfaces.
- Over-oxidation is possible: excessive dose/time can affect sensitive products (e.g., bruising risk, oxidative stress, aroma changes).
- Ozone is not a replacement for sanitation design: it complements hygienic equipment, good water management, and GMPs.
Regulatory and safety notes
Food contact status (U.S.)
In the United States, FDA regulations allow ozone in gaseous and aqueous phases as an antimicrobial agent for treatment, storage, and processing of foods (21 CFR 173.368; final rule published June 26, 2001).
EU context (biocidal framework)
In the EU, “ozone generated from oxygen” is approved as an active substance for certain biocidal product types under Regulation (EU) No 528/2012 via Commission Implementing Regulation (EU) 2023/1078 (with an approval start date of 1 July 2024 and expiry 30 June 2034).
Worker exposure
Ozone is toxic to inhale. For example, OSHA lists a permissible exposure limit of 0.1 ppm as an 8-hour TWA. Industrial installations should include gas monitors, ventilation, interlocks, and off-gas destruction.
Practical implementation checklist for produce processors
If you’re evaluating ozone for produce washing, we need to:
- Pilot first on your actual commodity mix and worst-case organic load
- Design for consistent dissolved ozone at the point of use (not just generator capacity)
- Include filtration + water refresh strategy to control ozone demand
- Build in CIP and hygienic design so the wash system doesn’t become the contamination source
- Specify materials compatibility (ozone attacks many elastomers and plastics)
- Validate with micro testing + shelf-life studies under your storage conditions
- Implement safety engineering: monitors, destruct, ventilation, and procedures
How we support industrial ozone produce-wash projects
As an industrial ozone generator supplier, we typically deliver more than the generator: complete dissolved ozone skids, injection/contact hardware, sensors and controls, off-gas destruction, and commissioning support—because produce washing performance is a system outcome, not a single component.