Case Studies

Purfresh has proven that ozone application is successful in disinfecting, stopping or removing mold growth, reducing contamination and decay, and improving shelf life.

Cold Storage Case-Tomatoes #1, Cold Storage Case-Tomatoes #2, Cold Storage Case-Lemons #1, Cold Storage Case-Lemons #2, Cold Storage Case-Table Grapes, Cold Storage Case-Kiwifruit, Disinfection Case-Apples, Disinfection Case-Canteloupes, Disinfection-Strawberries

COLD STORAGE CASE – Tomatoes #1

Customer Problem
A major high end tomato grower/packer needing to control Botrytis as well as add an additional step for food safety and reduce use of chemicals such as chlorine.

Solution
Purfresh Cold Storage applying enhanced ozone atmosphere in cold storage as well as Purfresh Wash spray bar disinfection, applying ozonated water to spray bar on packing line.

Results
Improved shelf life and quality of tomatoes going to high end restaurants on East Coast, no slowing of business during 2008 salmonella scare with strength of food safety program including Purfresh ozone systems.

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COLD STORAGE CASE – Tomatoes #2

Customer Problem
One of the nation’s largest grower/packers was looking to control decay and ripening as well as improve sanitization in tomato storage.

Solution
Purfresh Cold Storage enhanced ozone atmospheres in 24 tomato ripening rooms.

Results
Targeted ripening control improved marketability of tomatoes holding precise color, reduced overall decay and enhanced shelf life. Able to turn rooms faster and enhanced sanitization.

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COLD STORAGE CASE – LEMONS #1

Customer Problem
A major citrus producer had excessive contamination in a cold room consisting of 175,000 cubic feet. Lemons contained over 3 million colony forming units of microorganisms per gram.

Solution
Ozone as a gas was applied for one night at specifications provided by Purfresh.

Results
Siliker Labs provided the independent testing. The results were widespread and substantial.

– Reduced contaminants by 2-3 log count
– Reduced ethylene-ripening losses
– Reduced mold spore-related losses
– Extended shelf life and improved product value

The table below depicts actual findings:
 

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COLD STORAGE CASE – LEMONS #2

Customer Problem
One of the largest packing associations in the world had significant losses from cross- contamination of mold spores.

Solution
Ozone was applied continuously in gaseous form over 100 days based on Purfresh specifications within OSHA safety limitations. Purfresh system monitored ozone levels.

Results
Mold in the lemons treated with ozone was minimal, and was limited to the lemons that were infected prior to storage, as shown in the picture to the right.

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COLD STORAGE CASE – TABLE GRAPES

Customer Problem
A premier grower of table grapes with multiple cold storage facilities in California’s San Joaquin Valley used sulfur dioxide in its cold storage rooms.  The sulfur dioxide caused equipment corrosion in the grower's cold storage rooms, and still failed to prevent significant losses of its grapes to botrytis. The grower also planned to enter the organic market, where sulfur dioxide is prohibited by the USDA. Thus, they needed a safer and more effective cold storage treatment solution.

Solution
For conventional product, ozone was applied continuously in gaseous form within OSHA limits in conjunction with lower levels of SO₂. For organic product, ozone alone was applied.

Results
The results were widespread and substantial.

– Organic grapes thrived under ozone treatment (USDA Organic Rule in 2000)
– Reduced SO2 by two-thirds
– Reduced contaminants
– Reduced mold spore-related losses
– Extended shelf life and improved product value

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COLD STORAGE CASE – KIWIFRUIT

Customer Problem
A multi-national packer with 60 years of operating history could no longer sustain 35 percent spoilage rates with kiwifruit. The targeted storage room in California contained 1,300 bins of kiwis.

Solution
Ozone was applied continuously in gaseous form based on Purfresh specifications within OSHA worker safety limitations. Purfresh system also monitored ozone levels.

Results
The results were widespread and substantial.

– Spoilage reduced from 35% to less than 5%
– Reduced contaminants by 2-3 log count
– Reduced ethylene to non-detectable levels
– Reduced mold growth
– Extended shelf life
– Improved product quality
– Increased product value

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DISINFECTION CASE – APPLES

Customer Problem
One of the largest caramel apple packaging facilities in the country is a Purfresh customer. The apple treatment process used previously at this plant consisted of a recirculating flume of water that was chlorinated to control microorganisms. The flume had to be dumped daily, primarily because it accumulated high levels of organics and soil. Electronic Power Research Institute (EPRI) conducted a study for this company, in which ozone was applied in place of chlorine.

Solution
Apples were exposed to ozonated water for a short period of time.

Results
The results were substantial and confirmed by EPRI.

– Water reusage increased from 1 day to 7 days
– Yeast and mold were reduced by 2-3 log count
– Shelf life was extended and average quality improved

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DISINFECTION CASE – CANTELOUPES

Customer Problem
An international cantaloupe packer with a facility in Dominican Republic was confronted with disinfecting highly contaminated crops. Spoilage was significant due to the inability to effectively disinfect. Crops contained over 6 million colony forming units of microorganisms per gram

Solution
Cantaloupes were ozonated in two aqueous applications for a short period of time.

Results
The results were substantial and confirmed by National Food Labs.

– Reduced contaminants by 3-4 log count
– Stopped mold growth
– Extended shelf life and improved average product quality

The table below depicts actual findings:

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DISINFECTION – STRAWBERRIES

Internal Research
Purfresh applied ozone gas for a short period of time to process harvested strawberries. Thereafter, both ozonated and treated strawberries were stored in separate but identical conditions.

Results
The results after two weeks of storage were widespread and substantial.

– Reduced contaminants by 3-4 log count
– Untreated product was visually unacceptable
– Reduced mold and yeast growth to nominal levels

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