A survey of nitrite concentrations in retail fresh vegetables.

A survey of nitrite (NO2-) in fresh retail vegetables was conducted in the UK over twelve months. Samples of lettuce, cabbage, spinach, potatoes and carrots were bought at two-monthly intervals and analysed within 30 h of purchase using a method developed for fresh vegetables. Of 606 edible samples, 566 (93.4%) had no detectable NO2-, and 40 (mainly potatoes) contained trace amounts (< 0.4 mg kg-1). Four samples (spinach) which had deteriorated during their shelf-life and were considered inedible had amounts ranging from 12 to 222 mg kg-1 NO2-. The results confirm that poor storage is a rare occurrence in retail vegetables in the UK.