Assessment of dietary exposure of nitrate and nitrite in France

The aim of this study was to assess the dietary exposure of nitrate and nitrite in France. A total of 13, 657 concentration levels of nitrate and nitrite measured in food, representing 138 and 109 food items, respectively, and coming from French monitoring programmes between 2000 and 2006, were used. Depending on the non-detected and non-quantified analysis treatment, lower and upper concentration mean estimates were calculated for each food item. These were combined with consumption data derived from 1474 adults and 1018 children from the French national individual consumption survey (INCA1), conducted in 1999 and based on a 7-day food record diary. A total of 18% of spinaches, 6% of salads, 10% of cheeses, 8% of meat products and 6% of industrial meat products exceeded the European nitrate maximum level or maximum residual level. A total of 0.4% of industrial meat products and 0.2% of meat products exceeded their European nitrite maximum level or maximum residual level. Nitrate dietary exposure averaged 40% of the acceptable daily intake (ADI; 3.7 mg kg(-1) body weight day(-1)) for adults and 51 - 54% of the ADI for children with the major contributors being, for adults and children, respectively, vegetables (24 and 27% of ADI), potatoes (5 and 11% of ADI), and water (5 and 5% of ADI). The individual nitrate dietary intake of 1.4% (confidence interval (CI(95th)) [0.8; 2.0]) to 1.5% (CI(95th) [0.9; 2.1]) of adults and 7.9% (CI(95th) [6.2; 9.6]) to 8.4% (CI(95th) [6.7; 10.1]) of children were higher than the ADI. Nitrite dietary exposure averaged 33-67% of the ADI (0.06 mg kg(-1) body weight day(-1)) for adults and 67-133% of the ADI for children, with contributions of additive food vectors at 33% of ADI for adults and 50-67% of ADI for children. The individual nitrite dietary intake of 0.7% (CI(95th) [0.3; 1.1]) to 16.4% (CI(95th) [14.5; 18.3]) of adults and 10.5% (CI(95th) [8.6; 12.4]) to 66.2% (CI(95th) [63.3; 69.1]) of children were higher than the ADI.     

Estimated dietary intake of nitrite and nitrate in Swedish children

This study examines the intake of nitrate and nitrite in Swedish children. Daily intake estimates were based on a nationwide food consumption survey (4-day food diary) and nitrite/nitrate content in various foodstuffs. The mean intake of nitrite from cured meat among 2259 children studied was 0.013, 0.010 and 0.007 mg kg(-1) body weight day(-1) in age groups 4, 8-9 and 11-12 years, respectively. Among these age groups, three individuals (0.1% of the studied children) exceeded the acceptable daily intake (ADI) of 0.07 mg nitrite kg(-1) body weight day(-1). The mean intake of nitrate from vegetables, fruit, cured meat and water was 0.84, 0.68 and 0.45 mg kg(-1) body weight day(-1) for children aged 4, 8-9 and 11-12 years, respectively. No individual exceeded the ADI of 3.7 mg nitrate kg(-1) body weight day(-1). However, when the total nitrite intake was estimated, including an estimated 5% endogenous conversion of nitrate to nitrite, approximately 12% of the 4-year-old children exceeded the nitrite ADI. Thus, the intake of nitrite in Swedish children may be a concern for young age groups when endogenous nitrite conversion is included in the intake estimates.     

Estimated dietary intake of nitrite and nitrate in Swedish children

This study examines the intake of nitrate and nitrite in Swedish children. Daily intake estimates were based on a nationwide food consumption survey (4-day food diary) and nitrite/nitrate content in various foodstuffs. The mean intake of nitrite from cured meat among 2259 children studied was 0.013, 0.010 and 0.007?mg?kg^?1?body?weight?day^?1 in age groups 4, 8–9 and 11–12 years, respectively. Among these age groups, three individuals (0.1% of the studied children) exceeded the acceptable daily intake (ADI) of 0.07?mg?nitrite?kg^?1 body weight?day^?1. The mean intake of nitrate from vegetables, fruit, cured meat and water was 0.84, 0.68 and 0.45?mg?kg^?1 body weight?day^?1 for children aged 4, 8–9 and 11–12 years, respectively. No individual exceeded the ADI of 3.7?mg?nitrate?kg^?1 body weight?day^?1. However, when the total nitrite intake was estimated, including an estimated 5% endogenous conversion of nitrate to nitrite, approximately 12% of the 4-year-old children exceeded the nitrite ADI. Thus, the intake of nitrite in Swedish children may be a concern for young age groups when endogenous nitrite conversion is included in the intake estimates.     

Dietary exposure of Hong Kong adults to nitrate and nitrite from vegetable intake

The aim of this study was to assess the dietary exposure of adults in Hong Kong to nitrate and nitrite from vegetables. If all vegetables consumed were raw, the dietary exposure to nitrate for average consumers was estimated to be 4.4?mg?kg^?1 body weight (bw)?day^?1 and, for high consumers, was estimated to be 13?mg?kg^?1?bw?day^?1, which is about 120 and 350% of acceptable daily intake (ADI), respectively. If all vegetables consumed were cooked, the dietary exposure to nitrate from vegetables for the average adult consumer was estimated to be 3.5?mg?kg^?1?bw?day^?1 and, for high consumer, was estimated to be 10?mg?kg^?1?bw?day^?1, which is about 95 and 270% of ADI, respectively. On the other hand, the dietary exposure to nitrite from vegetables for average and high consumers were well below the ADI.     

Inactivation of Yersinia enterocolitica by nitrite and nitrate in food.

The antimicrobial effects of sodium nitrite and sodium and potassium nitrate against Yersinia enterocolitica were investigated in solution and in treated pork meat. Potassium nitrate and sodium nitrate showed only feeble antimicrobial activity in cultures; no antimicrobial activity was detected with sodium nitrite. Conversely, all three salts displayed apparent antimicrobial activity in pork meat, possibly due to selective effects on competitive flora.     

蔬菜中硝酸盐与亚硝酸盐检测方法的研究进展

综述了亚硝酸盐和硝酸盐的检测方法,指出了各检测方法的优劣及其应用前景,对于监控蔬菜生产加工中硝酸盐和亚硝酸盐的含量,检测蔬菜产品的品质等具有参考意义。     

蔬菜中硝酸盐和亚硝酸盐的污染

综述了硝酸盐和亚硝酸盐的危害、污染来源、蔬菜中的污染现状、蔬菜中硝酸盐积累机理及控制措施。     

Survey of nitrate and nitrite contents of vegetables grown in Korea.

A scientific basis for the evaluation of the risk to public health arising from excessive dietary intake of nitrate in Korea is provided. The nitrate () and nitrite () contents of various vegetables (Chinese cabbage, radish, lettuce, spinach, soybean sprouts, onion, pumpkin, green onion, cucumber, potato, carrot, garlic, green pepper, cabbage and Allium tuberosum Roth known as Crown daisy) are reported. Six hundred samples of 15 vegetables cultivated during different seasons were analysed for nitrate and nitrite by ion chromatography and ultraviolet spectrophotometry, respectively. No significant variance in nitrate levels was found for most vegetables cultivated during the summer and winter harvests. The mean nitrates level was higher in A. tuberosum Roth (5150 mg kg(-1)) and spinach (4259 mg kg(-1)), intermediate in radish (1878 mg kg(-1)) and Chinese cabbage (1740 mg kg(-1)), and lower in onion (23 mg kg(-1)), soybean sprouts (56 mg kg(-1)) and green pepper (76 mg kg(-1)) compared with those in other vegetables. The average nitrite contents in various vegetables were about 0.6 mg kg(-1), and the values were not significantly different among most vegetables. It was observed that nitrate contents in vegetables varied depending on the type of vegetables and were similar to those in vegetables grown in other countries. From the results of our studies and other information from foreign sources, it can be concluded that it is not necessary to establish limits of nitrates contents of vegetables cultivated in Korea due to the co-presence of beneficial elements such as ascorbic acid and alpha-tocopherol which are known to inhibit the formation of nitrosamine.     

Analysis of nitrate and nitrite in feed. 2. Potentiometric nitrate determination with ion sensitive electrodes]

Nitrate-sensitive PVC matrix membrane electrodes produced in the German Democratic Republic are suited for determining nitrates in feeds and plants if the different causative parameters are taken into account. A rational determining method is presented. Comparisons with the o-cresol method showed statistically confirmed agreement.     

Analytical methods for nitrate and nitrite in feeds. 1. Spectrophotometric determination of nitrate with o-cresol]

The o-cresol procedure which is used for determining nitrate in feeds is tested for precision. The treatment of the samples and the course of analysis are rationalized. The method is recommended as a standard procedure for biological materials; it is suited as a reference technique in elaborating new analytical procedures.     

The microbiological role of nitrite and nitrate

In unheated products nitrite, together with sodium chloride and the pH value, contributes to the selection of the bacteria which grow during storage. Nitrate per se is generally believed to serve only as a reservoir for nitrite, but the commercial use of nitrate-free cover brines in the Wiltshire bacon industry shows that such a reservoir is not always essential. Nitrate sometimes reduced the growth rate of bacteria in experimental Wiltshire collar bacon, but was of no benefit in back bacon. The clostridia occurring naturally in the bacon grew to higher numbers in collar cured without nitrate than that cured with nitrate. Clostridium botlinum (types A and B) was detected in these bacons, but did not grow in the bacon. In heated products the growth of surviving bacteria is controlled by the interaction of several factors including pH, sodium chloride, storage temperature and sodium nitrite or a substance derived from it upon heating. Further experiments are warranted to investigate the effects of dextrose, nitrate, ascorbate and polyphosphate.     

食品中的硝酸盐和亚硝酸盐探析

硝酸盐和亚硝酸盐是一类允许使用的食品添加剂,在国家标准限量范围内使用,你可以尽享人间美味.然而不正常的食用或误食,轻则造成食物中毒,重则引发癌症肿瘤.我国每年均有多起硝酸盐或亚硝酸盐的中毒事件.为了降低和阻止食品中的天然的或添加的硝酸盐和亚硝酸盐对人体的毒副作用,我们必须了解哪些食品中含有较多的硝酸盐和亚硝酸盐,哪些食品在加工过程中使用或不恰当使用硝酸盐和亚硝酸盐,哪些食品或食品中的有效成分能阻断亚硝胺的形成等等的问题.     

Naturally occuring nitrate/nitrite in foods

A review of the occurrence of nitrate in unprocessed foods showed that high concentrations are frequently found in vegetables. Spinach and lettuce commonly exceed 1000 parts/10⁶ nitrate while, of the root vegetables, beets, turnips and radishes are similarly rich in nitrate. In general, the pulses contain less nitrate than leaf and root vegetables, and most fruits contain little nitrate. Fresh dairy produce is usually low in nitrate. Well waters in some agricultural areas may contain nitrate concentrations so high as to represent a hazard if used as the sole water source for infants, but municipal supplies in the UK rarely exceed 45 parts/10⁶ although they frequently approach this. It is concluded that vegetables and water supplies make a greater contribution to the mean weekly nitrate intake than do cured meats. Nitrite concentrations are usually very low in fresh, undamaged fruits, vegetables and drinking water but adverse storage conditions can lead to (mainly microbial) reduction of nitrate. In these circumstances vegetables naturally rich in nitrate may accumulate nitrite at concentrations which can be toxic to infants.     

Analytical methods for nitrate and nitrite determination in foods. 3. Spectrophotometric determination of nitrate and nitrite using sulphanilic acid/1-naphylamine, and of nitrite using resorcinol/zirconium (IV) oxychloride

The Nitrate content of foods may be determined by means of azo-dye coupling after reduction of the nitrate with the aid of active cadmium produced in the sample solution. An easy method for determining nitrite consists in the colorimetric estimation of a coloured chelate formed from nitrite, resorcinol and zirconium(IV) oxychloride.     

Assessment of dietary exposure of young Chinese children to aluminium residues

The aim of this study was to assess the Al dietary exposure of young Chinese children aged 0–3 years via formulae, complementary foods and wheat-based foods. Al residue data were obtained from the national food contamination monitoring programme from 2013 to 2016, encompassing 13,833 samples of 12 food items with a detection rate of 76.0%. Food consumption data were gathered from the China National Food Consumption Survey conducted in 2015, comprising 20,172 children aged 0–3 years old. The mean dietary exposure to Al for the general population of young Chinese children was estimated at 0.76 mg/kg bw/week, which does not exceed the PTWI. The 97.5th percentile intakes of Al reached 3.42 mg/kg bw/week, more than 1.7 times the PTWI. Wheat-based foods contributed 80.5% of the Al intake for the general population of young Chinese children, while formulae and complementary foods accounted for 19.5% of the total intake. The dietary intake of Al from formulae and complementary foods accounted for 6.0% and 1.6% of PTWI, respectively. These findings suggested that dietary exposure to Al among the general population of young Chinese children was lower than the PTWI and that there are no health concerns related to this level of Al intake. However, more attention should be placed on the health risks associated with Al exposure from wheat-based foods for young consumers with high food consumption in China (97.5th percentile)     

蔬菜中硝酸盐与亚硝酸盐的积累规律与控制方法

目前对蔬菜生产和加工中硝酸盐和亚硝酸盐的形成积累规律还缺乏清楚的认识和理解,对蔬菜中硝酸盐含量也没有系统的控制方法。文章对蔬菜,特别是叶类蔬菜中硝酸盐和亚硝酸盐的积累规律和控制方法进行了综述,以指导无公害蔬菜的生产。     

The toxicology of nitrate,nitrite and n-nitroso compounds

Nitrate is essentially non-toxic to mammals but it can be reduced to nitrite either in improperly stored food, in the rumen of cattle, in the gastrointestinal tract of the human infant, and by the microflora of the human mouth. The nitrite from these and other sources, including that purposely added to food, presents a toxic hazard both because of the direct toxicity of nitrite, and by the formation of carcinogenic N-nitroso compound by reaction with amino compounds. Administration of toxic amounts of nitrite induces methaemoglobinaemia. The nature of this disease, its importance in human medicine and the reason for the particular sensitivity of the infant, are briefly discussed. The carcinogenic properties of N-nitroso compounds are described. These compounds have been found in the environment and may be formed in the stomach from amines and nitrite. Our knowledge of the amount of N-nitroso compounds to which man is exposed, is continually increasing but with the lack of epidemiologic evidence, the assessment of the significance to man of these traces of N-nitroso compounds depends upon the interpretation of animal experiments and their extrapolation to man. This extrapolation would be more certain if there were a more clear understanding of the factors determining tissue selectivity by carcinogens and tissue sensitivity, and of the mechanism of cumulation of carcinogenic doses and of synergism between carcinogens. Recent experiments suggest that there may soon be a significant breakthrough in the understanding of this. These experiments are briefly discussed.     

Assessment of the dietary habits and polycyclic aromatic hydrocarbon exposure in primary school children

Thirty Italian children, 7–9 year aged, living in Naples were investigated on their dietary habits and on polycyclic aromatic hydrocarbon (PAH) exposure by a food diary-questionnaire and one week duplicate diet sample analyses. Daily total food consumption mean value was 632 ± 215 g day^?1, median value 613 g day^?1. The daily energy intake and the diet composition meanly agreed with the official guidelines for the Italian children. Sixteen PAHs were simultaneously detected and, according to the European Food Safety Authority (EFSA) approach, benzo[a]pyrene; benzo[a]pyrene + chrysene (PAH2); PAH2 + benz[a]anthracene + benzo[b]fluoranthene (PAH4); PAH4 + benzo[k]fluoranthene + benzo[ghi]perylene + dibenz[a, h]anthracene + indeno[1,2,3-cd]pyrene (PAH8) were considered in evaluating the children's dietary exposure to PAHs. The benzo[a]pyrene (BaP) median concentrations in foods varied from 0.06 to 0.33 µg kg^?1. Only three samples of cooked foods (one fish and two meat samples) exceeded legal limits fixed by the European Union for BaP. Daily median intakes of benzo[a]pyrene, PAH2, PAH4, and PAH8 were 153; 318; 990; 1776 ng day^?1; their median exposure values were 5; 10; 28; 54 ng kg^?1 bw day^?1. The Margins of Exposure (MOEs) in median consumers agreed with the EFSA safety values except for PAH8.