Review of the occurrence and formation of non-volatile N-nitroso compounds in foods.

A review of the literature published prior to July 1991 covers the occurrence and formation of non-volatile N-nitrosamines occurring in foods and beverages. The presence of identified volatile and non-volatile N-nitrosamines accounts for less than 10% of the total apparent N-nitrosamine concentration. N-Nitrosoproline and N-nitrosothiazolidine-4-carboxylic acid are the most commonly identified non-volatile N-nitrosamines in the diet. Non-volatile N-nitrosamines account for 12 of the 21 currently identified N-nitroso compounds in foods and beverages.     

Reactions of nitrate and nitrite in foods with special reference to the determination of N-nitroso compounds.

The stabilities of nitrate and nitrite in food systems and their reactions in such matrices are reviewed. Particular reference is made to reactions with haem proteins, smoke components and amines in foods, and the chemistry of formation of N-nitroso compounds from food components is discussed. Finally, the methodology available for determination of both volatile and non-volatile N-nitroso compounds is addressed.     

Examination of some fermented foods for the presence of apparent total N-nitroso compounds

The fermented foods yoghurt, bread and cheese were analysed for the presence of apparent total N-nitroso compounds (ATNC) by a group-selective procedure involving direct chemical denitrosation and chemiluminescence detection of the released nitric oxide. The levels of ATNC were below the 20 micrograms(N-NO)/kg detection limit in all 20 yoghurts, 23 of the 24 bread samples and 28 out of 31 different varieties of cheese analysed. ATNC were detected in most of those cheese samples manufactured with added nitrate, including Edam, Gouda and Havarti, in concentrations ranging from 30 to 210 micrograms(N-NO)/kg.     

Nitrate, nitrite, and N-nitroso compounds in Finnish foods and the estimation of the dietary intakes

An estimate of the dietary intakes of nitrite, nitrate and N-nitroso compounds is presented, based on the analytical data supplied by the Finnish Food Quality Control. Figures on the food consumption of the Finnish population, taken from a national dietary survey, and food consumption of 1768 children and adolescents over a 48-h recall period were used. The mean daily dietary nitrate intakes were estimated to be about 55 mg for the total population and for children and adolescents. The mean nitrite intakes were 1.88 mg for the total population and 1.07 mg for children and adolescents. The intake of N-nitroso compounds (NDMA) was estimated to be 0.08 micrograms for the total population and 0.02 micrograms for children. Nitrates were found to originate mainly from vegetables (80%), nitrites from meat products (97%) and nitrosamines mostly from fish products and beer. A comparison of the estimate of dietary intake of with ADI values indicated that the nitrite intake of the total population was 23% and by children 39% of ADI. The average weight was approximately 60 kg for adults and 20 kg for children. When measured average weight (39 kg) was used, and the nitrite intake was found to be 28% of ADI. Nitrate intakes from food additives were 2.5% and 1.4% of the ADI value, respectively. When the total nitrate intake from various food sources was compared with the ADI (which is given only for food additives), the estimated nitrate intake of the total population was 25% and that of children 28% of the ADI value.     

Nitrate, nitrite, and N-nitroso compounds in Finnish foods and the estimation of the dietary intakes

Summary An estimate of the dietary intakes of nitrite, nitrate andN-nitroso compounds is presented, based on the analytical data supplied by the Finnish Food Quality Control. Figures on the food consumption of the Finnish population, taken from a national dietary survey, and food consumption of 1768 children and adolescents over a 48-h recall period were used. The mean daily dietary nitrate intakes were estimated to be about 55 mg for the total population and for children and adolescents. The mean nitrite intakes were 1.88 mg for the total population and 1.07 mg for children and adolescents. The intake ofN-nitroso compounds (NDMA) was estimated to be 0.08 g for the total population and 0.02 g for children. Nitrates were found to originate mainly from vegetables (80%), nitrites from meat products (97%) and nitrosamines mostly from fish products and beer. A comparison of the estimate of dietary intake of nitrite with ADI values indicated that the nitrite intake of the total population was 23% and by children 39% of ADI. The average weight was approximately 60 kg for adults and 20 kg for children. When measured average weight (39 kg) was used, and the nitrite intake was found to be 28% of ADI. Nitrate intakes from food additives were 2.5% and 1.4% of the ADI value, respectively. When the total nitrate intake from various food sources was compared with the ADI (which is given only for food additives), the estimated nitrate intake of the total population was 25% and that of children 28% of the ADI value.

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Nitrat, Nitrit und N-nitroso-Verbindungen in der finnischen Nahrung

Zusammenfassung Die Einnahme von Nitrat, Nitrit undN-Nitroso-Verbindungen stützt sich auf die analytischen Werte der finnischen Lebensmittelkontrolle. Für die Schätzung der Nahrungsaufnahme der finnischen Bevölkerung benutzte man Resultate einer nationalen Nahrungsforschung und eines 48-Stunden-Befundes für 1768 Kinder und Jugendliche. Die durchschnittliche tägliche Einnahme von Nitrat schätzte man auf ungefähr 55 mg für die ganze Bevölkerung. Die durchschnittliche Einnahme von Nitrit betrug 1,88 mg für die ganze Bevölkerung und 1,07 mg für Kinder und Jugendliche. Die Einnahme vonN-Nitroso-Verbindungen (NDMA) schätzte man auf 0,08 g für die ganze Bevölkerung und 0,02 g für Kinder. Die hauptsächliche Nahrungsquelle der Nitrate war Gemüse (80%) und bei den Nitriten die Fleischwaren (97%). Nitrosamine stammten hauptsächlich aus Fischwaren und aus Bier. Als man die geschätzte Einnahme von Nitrit mit den ADI-Werten verglich, ergab sich, daß die Einnahme von Nitrit 23% (ganze Bevölkerung) und 39% (Kinder) des ADI-Wertes war. Als durchschnittliches Körpergewicht nahm man 60 kg für Erwachsene und 20 kg für Kinder an. Wenn man den Wert des gemessenen durchschnittlichen Körpergewichts (39 kg) für Kinder benutzte, war die Einnahme von Nitrit 28% des ADI-Wertes. Die Einnahme von Nitrat in Zusatzstoffen war 2,5% und entsprechend 1,4% des ADI-Wertes. Die Einnahme von Nitrat in der Nahrung schätzte man auf 25% (ganze Bevölkerung) und auf 28% (Kinder) des ADI-Wertes (gegeben nur für Nitrat als Zusatzstoffe).

     

The collaborative evaluation of a procedure for the determination of N-nitroso compounds as a group

Two collaborative studies have been made of the method devized for the determination of N-nitroso compounds as a group, which involves their selective denitrosation with hydrogen bromide in glacial acetic acid, followed by the measurement of the nitric oxide liberated using a chemiluminescence analyzer, such as the TEA. Considerable variation was evident between the results in the first study, most of the values reported being low. This situation undoubtedly arose from the carry-over of traces of hydrogen bromide from one determination to the next, which resulted in premature denitrosation. The precision and consistency of the results were greatly improved in the second study, for which additional precautions had been recommended. All of the six participating laboratories reported reasonably consistent values, the coefficients of variation being 27.9% and 21.1% respectively, at the levels of spiking of N-nitrososarcosine equivalent to 32.9 ng and 146.4 ng of nitric oxide.     

Significance of sample preparation in developing analytical methodologies for accurate estimation of bioactive compounds in functional foods

Functional foods are defined as foods or food components that provide health benefits beyond basic nutrition (for the intended population). Increased interest in bioactive food components and phytochemicals has arisen from numerous epidemiological studies that suggest that certain phytochemicals can reduce risk of chronic diseases. Sales of functional foods containing high concentrations of bioactive components have increased dramatically during the past two decades. This paper illustrates with examples the significance of sample preparation in developing analytical methodologies for accurate estimation of potentially bioactive compounds present in functional foods using phenolic phytochemicals as model substrates. The primary three steps in any analysis are sampling, sample preservation, and sample preparation. These three initial steps are often overlooked and considered ‘as a means to an end’ and are often not well documented in the published literature. This paper outlines a systematic protocol for optimizing extraction of phytochemicals from different plant matrices. Accurate analysis of bioactive compounds is critical for their precise and reproducible quantification in different foods, establishing appropriate dietary intake and safety guidelines, and understanding their role in human health and nutrition. Copyright © 2006 Society of Chemical Industry     

食品中性激素多组分残留分析方法的概述

综述了最近报道的关于应用色谱法检测食品中性激素多组分残留的分析方法。首先对性激素作简短的介绍,然后着重概述了性激素多组分残留的分析方法,包括样品的提取、纯化和各种不同的检测方法,并对各种不同的分析方法进行详细阐述。最后总结了性激素多组分残留检测方法的发展趋势。     

The application of a chemical denitrosation and chemiluminescence detection procedure for estimation of the apparent concentration of total N-nitroso compounds in foods and beverages

The apparent total N-nitroso content of foods can be measured by a procedure based on chemical denitrosation and chemiluminescent detection of the eliminated nitric oxide. Procedures have been established which substantially reduce the 'apparatus blank' response to the denitrosating agent and allow total nitroso contents down to 10 micrograms (N-NO)/kg to be measured reproducibly on a 1-g sample. Typically, duplicate analyses of samples containing 10-1000 micrograms (N-NO)/kg differ by less than 15% of their mean. Potentially the method can be subject to some interference from compounds other than N-nitroso compounds, but at least in some commodities these interfering compounds do not exist in measurable amounts.     

N-亚硝基化合物对食品安全的污染及其对策

从N-亚硝基化合物来源出发,对食品中N-亚硝基化合物的危害,机理进行综合分析,并提出预防和控制食品中N-亚硝基化合物的具体措施,为进一步提高人们对食品安全的正确认识,提供科学的参考.     

食品中甜味剂的检测方法

文章引用文献一百多篇,比较详细地对近年来食品中甜味剂检测中应用的各种技术方法进行了总结。     

Mutagenicity of N-nitroso compounds in Chilean ham and sausages

Chilean hams and sausages were analysed for the presence of nitrosodimethylamine and nitrosodiethylamine by GLC/NPD. The presence of 3.5–210ppb levels were found in 51.6% of the samples. All of the positive samples contained nitrosodimethylamine while only 11% of them contained nitrosodiethylamine. Mutagenicity assays were performed in Salmonella typhimurium . Strains TA 98 and TA 100 were used in absence and presence of S9 mix. A dose-response curve of the mutagenic activity was observed in TA 100 with S9 mix. Unscheduled DNA synthesis assay also confirmed that the purified extracts of hams and sausages at doses as low as 1 ppb are inducers of damage to DNA of human foetal lung cells.     

Incidence of some non-volatile N-nitroso compounds in cured meats

Procedures are described for the use of high-performance liquid chromatography and gas chromatography with a chemiluminescence detector in the analysis of N-nitrosoamino acids, N-nitrosothiazolidine-4-carboxylic acid, N-nitroso-oxazolidine-4-carboxylic acids and N-nitroso dipeptides N-terminal in N-nitrosoproline in cured meat products. The detection limit is around 5-10 micrograms/kg. Evidence is presented for the presence of all these species except the N-nitrosated dipeptides.     

Amadori化合物检测方法的研究进展

Amadori化合物是羰基化合物和氨基化合物发生美拉德反应生成的一类关键中间产物,除其本身的化学意义外,其后续反应产物对食品的颜色、风味、营养性、安全性、抗氧化性等品质都具有重要的影响。目前已经报道的Amadori化合物定性定量检测方法主要适用于红参、烟草和极小部分食品品种。本文综述了Amadori化合物的形成机理及其定性定量的检测方法,为建立用于广泛或复杂的食品样品中Amadori化合物的检测方法奠定基础。      

Precautions to be taken in the analysis of total N-nitroso compounds

Methodologies used to assess N-nitroso compounds as a group by chemical denitrosation with hydrogen bromide in glacial acetic acid have been described. Carrying out these analyses without precautions can cause considerable variations in results. Some pitfalls must be avoided in order to obtain valuable results and accurate interpretations.     

The problem and improvement of colorimetric method for determination of sulfite in foods containing sulfur compounds

The modified Rankine colorimetric method for measuring sulfite added to food as a food additive has a low determination limit and is little influenced by interfering substances from foods. However, it can give erroneous results for foods containing Liliaceae Allium. So, four different methods, alkaline titration, a colorimetric method, ion chromatography and qualitative analysis with potassium iodate-starch paper, were examined. It was found that the sodium azide used in the colorimetric method forms sulfur dioxide during bubbling and heating. The proposed colorimetric method can be applied to food containing sulfur compounds, if sodium azide is omitted and 1% triethanolamine solution is used as an absorbent instead of 0.1 mol/L sodium hydroxide solution.     

Fast extraction methodologies for the determination of toxic arsenic in meat

A nonchromatographic analytical procedure has been developed for the determination of arsenic in meat samples including the major toxic arsenic species arsenite, arsenate, monomethylarsonic acid (MMA) and dimetylarsinic acid (DMA). The method is based on the extraction of arsenic species in mild conditions, selective trivalent hydride formation and final determination by hydride generation atomic fluorescence spectroscopy (HG‐AFS). Different extractant agents and two different procedures, microwave‐assisted extraction (MAE) and ultrasound assisted extraction at room temperature, were evaluated for As species extraction. The method provided a limit of detection of 0.013 ng mL^?1 and a mean relative standard deviation in actual samples of 0.3%. Data found for toxic As in meat samples varied from 0.42 ng g^?1 in chicken muscle to 68 ng g^?1 in pork liver. Percentage of toxic As respect to total As varied in the 9–46% range depending on the meat product.     

HPLC法测定食品中金雀异黄素

为保证保健食品的质量,建立了测定食品中金雀异黄素的HPLC方法.试样以乙醚脱脂,甲醇+水(80+20,体积分数)超声提取30 min,定容后过0.45 μm滤膜,上250.0 mm×4.6 mm、粒径10 μm的C18柱,甲醇+醋酸铵(0.050 mol/L,pH 4.6)作流动相,二极管阵列检测器测定.染料木苷、黄豆苷、黄豆苷元对测定不产生干扰.方法回收率85%～110%,相对标准偏差2%～8%,最低检出限为0.10 μg.本方法适用于保健食品中金雀异黄素的测定.     

动物源性食品中喹噁啉类药物及其代谢物残留检测技术研究进展

喹噁啉类药物是一类具有抗菌活性的物质,同时具有促进蛋白质同化,增加瘦肉率,促进畜禽生长以及提高饲料转化率的作用,曾被用于猪、牛、鸡、羊的促生长。这类药物残留在畜禽产品中,可通过食物链进入人体。毒理学研究表明,喹乙醇(olaquindox,OLA)和卡巴氧(carbadox,CBX)具有明显的致癌、致畸、致突变的三致作用,严重威胁动物和人的健康安全。本文对喹噁啉类药物及其代谢物的危害和动物源性食品中的残留检测技术进行了综述及展望。     

腌肉制品中N-亚硝基化合物的研究进展

亚硝酸盐和硝酸盐在腌肉中能抑制肉毒梭状杆菌的生长繁殖、使腌肉产生典型的腌肉风味、使腌肉具有诱人的粉红色,还能产生抗氧化的作用,但是亚硝酸盐和硝盐能在肉中转化为亚硝化试剂和肉中的胺类物质反应,生成具有致突、致癌性的N-亚硝基化合物;本文综述了国内外肉制品中N-亚硝基化合物的资料,介绍了N-亚硝基化合物在腌肉制品中的发生、形成、影响因素及控制。