Effects of agriculture production systems on nitrate and nitrite accumulation on baby-leaf salads.

Alfredo Aires,Rosa Carvalho,Maria J Saavedra,Eduardo A S Rosa

doi:10.1002/fsn3.1

Alfredo Aires, Rosa Carvalho + Show 2 more

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https://doi.org/10.1002/fsn3.1

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Abstract

Nitrate and nitrite are widespread contaminants of vegetables, fruits, and waters. The levels of these compounds are increased as a result of using organic wastes from chemical industries, domestic wastes, effluents, nitrogenous fertilizers, and herbicides in agriculture. Therefore, determining the nitrate and nitrite levels in biological, food, and environmental samples is important to protect human health and the environment. In this context, we set this study, in which we report the effect of production system (conventional and organic) on the accumulation of nitrates and nitrites in fresh baby-leaf samples. The average levels of the nitrate () and nitrite () contents in six different baby-leaf salads of a single species (green lettuce, red lettuce, watercress, rucola, chard, and corn salad) produced in organic and conventional agriculture system were evaluated. Spectrophotometric analytical method recently published was validated and used. Nitrates and nitrites were detected in all samples. The nitrates levels from organic production varied between 1.45 and 6.40 mg/kg fresh weight (FW), whereas those from conventional production ranged from 10.5 to 45.19 mg/kg FW. The nitrites content was lower than nitrates and ranged from 0.32 to 1.89 mg/kg FW in organic production system and between 0.14 and 1.41 mg/kg FW in conventional production system. Our results showed that the nitrate content was dependent on the agricultural production system, while for nitrites, this dependency was less pronounced.

Highlights

Western countries are consuming “organically” grown foods with increasing quantity and frequency (Jensen et al 2011)
The term organic production is applied to unprocessed agricultural crop products or minimally processed foods, which have not received excessive amounts of chemicals such as synthetic pesticides and fertilizers, without genetically modified organisms (GMOs) (EU 1995; Luttikholt 2007)
The presence of nitrates is one of the consequences of the mechanism in which plants absorb the nitrogen element, in the form of NO3À, from fertilizers or organic materials (Gangolli et al 1994), which are essential for the process a 2012 The Authors

Summary

Introduction

Western countries are consuming “organically” grown foods with increasing quantity and frequency (Jensen et al 2011). The term organic production is applied to unprocessed agricultural crop products or minimally processed foods, which have not received excessive amounts of chemicals such as synthetic pesticides and fertilizers, without genetically modified organisms (GMOs) (EU 1995; Luttikholt 2007). In Portugal, a recent study from Agriculture Ministry (GPP 2011) reported an increase in organic production. As an alternative to conventional agricultural, relies on the incorporation of organic material in soil, normally by the use of animal manure as fertilizer (EU 1995). The presence of nitrates is one of the consequences of the mechanism in which plants absorb the nitrogen element, in the form of NO3À, from fertilizers or organic materials (Gangolli et al 1994), which are essential for the process a 2012 The Authors.

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