Abstract: It has been reported that the overintake of vegetables in which the level of nitrate exceeds the standard is seriously harmful to health. In this study, the effectiveness of immersion in different liquids, blanching and peeling in removing nitrate and nitrite from typical commercial vegetables in Wuhan city was spectrometrically evaluated according to the Chinese national standard. Immersion in vinegar, fruit and vegetable washing detergent or saline was effective differently in reducing the level of nitrate in vegetables, the maximum reduction percentages in Brassica chinensis and spinach were up to 32.5% and 23.4%, respectively. Blanching could effectively reduce the levels of nitrate in leaf vegetables, and the levels of nitrate in Brassica chinensis and spinach after 0.5 min of blanching in boiled water were decreased by 26.9% and 14.5%, respectively. Also, peeling was found to be an effective way to remove nitrate or nitrite from root and stem vegetables and fruit vegetables. The levels of nitrate in peeled white radish and cucumber exhibited a decrease of respectively 6.5% and 15.9% as compared to those before peeling, and the levels of nitrite in eggplant and white radish were reduced by 12.2% and 2.7%, respectively after peeling. Based on the above, we concluded that immersion, blanching and peeling before consumption can effectively reduce the levels of nitrate and nitrite in vegetables.

Key words: treatment before consumption, vegetables, nitrate, nitrite, removal rate