Influence of continuous exposure to gaseous ozone on the quality of red bell peppers, cucumbers and zucchini

The effect of continuous exposure to ozone on quality changes during the storage of red bell peppers, cucumbers and zucchini was investigated. Peppers were stored at 14°C and were exposed to ozone at 0.1 and 0.3μmolmol−1, while cucumbers and zucchini were stored at 12 and 8°C, respectively, and exposed to ozone at 0.1μmolmol−1. The content of fructose (2.75g/100g FW) and glucose (2.00g/100g FW) in red bell peppers exposed to ozone at 0.1μmolmol−1 was increased by 8 and 7%, respectively, when compared to controls. Continuous exposure to ozone at 0.3μmolmol−1, on the other hand, had no effect on fructose (2.52g/100g FW) and glucose (1.88g/100g FW) content. The content of vitamin C was significantly enhanced in red bell peppers exposed to ozone at 0.1 and 0.3μmolmol−1 after 7d of storage, however, this effect was not maintained. After 14d, vitamin C content in peppers exposed to ozone at 0.1μmolmol−1 was not significantly different from the control, whereas it was reduced at 0.3μmolmol−1. Total phenolics content was increased in peppers exposed to ozone at 0.1μmolmol−1, but was unaffected at 0.3μmolmol−1. Continuous exposure of red bell peppers to ozone at 0.1 and 0.3μmolmol−1 had no significant effect on weight loss, texture and colour. In cucumbers and zucchini, continuous exposure to ozone at 0.1μmolmol−1 reduced weight loss by more than 40% and improved texture maintenance, while having no significant effect on their biochemistry. The findings from this study suggest that continuous exposure to ozone at 0.1μmolmol−1 is a promising method for shelf-life extension of cucumbers and zucchini. Even though in red bell peppers continuously exposed to ozone at 0.1μmolmol−1 sugars and phenolics content was increased, further work is still needed to better understand the exact mechanism of ozone action and its potential for the industrial use.