Evaluation of nitrate and nitrite contents in pickled fruit and vegetable products

Our objective was to investigate nitrate and nitrite contents of acidified and fermented fruits and vegetables. l-ascorbic acid and total phenols were also examined based on the hypothesis that the presence of these antioxidant compounds may influence N-nitrosation reactions upon human consumption. The fermented and acidified vegetable products included 131 samples from multiple lots of 46 different commercially available products. Nitrite was detected in low concentrations (<1.5 mg/100 g) in four acidified (pickled green beans, red cabbage, pickled beets, and pickled mushrooms) and two fermented products (Greek olives and kimchi). Nitrate concentrations ranged from a mean value of 122 mg/100 g for kimchi to undetectable levels in acidified Brussels sprouts. Measures of antioxidant compounds showed that artichoke hearts had the highest total polyphenols (225 mg/100 g), and olive products had between 84 ± 5 mg/100 g (Spanish table olives) and 170 ± 8 mg/100 g (Greek olives). An acidified red pepper product had the highest l-ascorbic acid content of 32 ± 10 mg/100 g, with a low nitrate level of 0.1 ± 0.09 mg/100 g. These results provide new information for evaluating nitrate and nitrite contents in pickled fruit and vegetable products with regard to potential human dietary health consequences.