Strawberry Shelf Life after Exposure to Various CO2 Levels

March 18, 2008

Numerous scientific studies have been conducted conclusively demonstrating that strawberries exposed to CO2 (carbon dioxide) levels above 10% develop less decay (botrytis) and generally have longer shelf life.

The Tectrol process is a sealed system that is designed to maintain a CO2 atmosphere between 10-20%. This lab demonstration attempts to illustrate why high levels of CO2 are most beneficial in maintaining the retail quality of fresh strawberries.

Methods

Forty-nine clamshells were randomized and then divided among 6 treatment lots. Three strawberries in each clamshell were then inoculated with a live botrytis slurry/mixture. Matched samples were then placed in seven different atmosphere mixes, all at 35°F. Atmosphere treatments were: 1% CO2 and 21%O2, 3%CO2 and 21%O2, 5%CO2 and 15%O2, 10%CO2 and 10%O2, 15% CO2 and 5% O2 and 20%CO2 and 3%O2. Atmosphere selection was based on actual observed atmospheres for Tectrol as well as other competitive processes.

After 5 days, all samples were removed from atmosphere and placed in air at 45°F for 2 days. After one additional day at 70°F, strawberries were evaluated for decay, wet and leaky and good fruit.

Table 1 summarizes the results:


Table 1.

Conclusion:

The higher the CO2 levels, the greater the shelf life or number of good fruit. The target atmosphere for Tectrol is between 10-20% CO2 during the time the product is sealed in the bag. Data clearly demonstrates the value of maintaining high CO2 levels.