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Lettuce Study

Full-Scale, Mixed Load Container Testing with Air Cleaned by Bluezone® Model 2400


In three week test, Bluezone reduced russet spotting in lettuce by 78%.


To quantify the effectiveness of the Bluezone Model 2400 in maintaining quality and extending the shelf life of FF&V stored or shipped in mixed loads.

Methods and Materials

We conducted a side-by-side test of a mixed produce load over a 3-week storage period, to measure produce quality and the shelf life extension achieved with Bluezone Fresh Preservation Technology.


  • Two, 8’X8’X20’ Refrigerated Containers, each set to 34°F with ventilation sufficient to maintain CO2 below 1%.
  • Mixed produce load of ethylene sensitive and ethylene producing FF&V.
  • Temperature, humidity, carbon dioxide and ethylene measurements taken at regular intervals.
  • One container with Bluezone, second container without Bluezone.


  • 21 Days of Refrigerated Storage
  • 5-10 Additional days of ambient temp storage for specified FF&V


The Bluezone Model 2400 maintained ethylene concentration in the mixed load container at 0.6ppm throughout the 21-day test. Uncontrolled ethylene concentration was 10ppm.

This dramatic reduction in ethylene concentration had a significant impact on the quality of ethylene sensitive produce, such as lettuce.


Test Results for Lettuce

Storing lettuce in a mixed load environment with Bluezone operating to clean the air of ethylene decreased the incidence of russet spotting in iceberg lettuce by 78%.


Use of the Bluezone Fresh Preservation Technology significantly reduced russet spotting in wrapped iceberg Lettuce over the 21-day storage period.