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 degrees C and were exposed to ozone at 0.1 and 0.3 mu mol mol-1, while cucumbers and zucchini were stored at 12 and 8 degrees C, respectively, and exposed to ozone at 0.1 mu mol mol-1. The content of fructose (2.75 g/100 g FW) and glucose (2.00 g/100 g FW) in red bell peppers exposed to ozone at 0.1 mu mol mol(-1) was increased by 8 and 7%, respectively, when compared to controls. Continuous exposure to ozone at 0.3 mu mol mol(-1), on the other hand, had no effect on fructose (2.52 g/100 g FW) and glucose (1.88 g/100 g FW) content. The content of vitamin C was significantly enhanced in red bell peppers exposed to ozone at 0.1 and 0.3 mu mol mol(-1) after 7 d of storage, however, this effect was not maintained. After 14 d, vitamin C content in peppers exposed to ozone at 0.1 mu mol mol(-1) was not significantly different from the control, whereas it was reduced at 0.3 mu mol mol(-1). Total phenolics content was increased in peppers exposed to ozone at 0.1 mu mol mol(-1), but was unaffected at 0.3 mu mol mol(-1). Continuous exposure of red bell peppers to ozone at 0.1 and 0.3 mu mol mol(-1) had no significant effect on weight loss, texture and colour. In cucumbers and zucchini, continuous exposure to ozone at 0.1 mu mol mol(-1) reduced weight loss by more than40% and improved texture maintenance, while having no significant effect on their biochemistry. The findings from this study suggest that continuous exposure to ozone at 0.1 mu mol mol(-1) is a promising method for shelf-life extension of cucumbers and zucchini. Even though in red bell peppers continuously exposed to ozone at 0.1 mu mol mol(-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. (C) 2014 Elsevier B.V. All rights reserved.