Occurrence of polycyclic aromatic hydrocarbons in smoked cheese

The presence of polycyclic aromatic hydrocarbons (PAH) in smoked cheeses of different origin was studied. The samples were subjected to an initial extraction of fat and an alkaline treatment, extracted with cyclohexane, cleaned up by means of solid-phase extraction tubes, and analyzed by gas chromatography/mass spectrometry (GC/MS) operating in selective ion-monitoring mode (SIM). The results revealed the presence of numerous polycyclic aromatic hydrocarbons in the exterior zone of the samples, some of them with methyl groups. In all cases, the concentrations of compounds of low molecular weight were much higher than those of high molecular weight. Polycyclic aromatic hydrocarbons with varying degrees of carcinogenicity were identified, including benzo(a)pyrene in concentrations, which, although they did not exceed the limit established for this compound in the rind of ripened cheeses, do exceed the limit of 0.03 microg/kg fixed for other foods smoked with smoke flavorings. Significant differences in the number and concentration of PAH in smoked cheese also were observed from rind to interior, the rind being the most contaminated zone.     

Selected polycyclic aromatic hydrocarbons in smoked tuna, swordfish and Atlantic salmon fillets

The presence of polycyclic aromatic hydrocarbons (PAHs) in commercial smoked fillets of tuna, swordfish and Atlantic salmon was studied. In Europe, the smoking technique is widely used in fish processing and these species are the most representative of the taste of consumers for smoked products. Samples were purchased on the Italian market and analysed by HPLC. Mean concentrations (ng g⁻¹) of acenaphthene (4.4, 6.2, 11.2), phenanthrene (11.5, 18.5, 8.9), anthracene (2.4, 5.2, 1.8), fluoranthene (17.0, 9.4, 4.7), benzo( k )fluoranthene (0.3, 0.1, 0.2) and benzo( a )pyrene (1.3, 0.1, 0.4) were found in Atlantic salmon, tuna and swordfish respectively. Benzo( b )fluoranthene (1.2 ng g⁻¹) was detected only in Atlantic salmon whereas dibenz( a,h )anthracene was never detected in this species, but only in tuna (0.5 ng g⁻¹) and swordfish (1.1 ng g⁻¹). Atlantic salmon contained the highest level of benzo( a )pyrene (2.8 ng g⁻¹) which is below the European regulatory level of 5 ng g⁻¹.     

Effect of fuel and kiln type on the polycyclic aromatic hydrocarbon (PAH) levels in smoked shrimp,a Beninese food condiment

Smoked shrimp is a food condiment widely used in Beninese local cooking practices. A previous study revealed that this product is highly contaminated with polycyclic aromatic hydrocarbons (PAH). The present study explored possibilities to reduce PAH levels in shrimp smoked using cottage industry smoking techniques with barrel and chorkor kilns, by replacing wood by charcoal from Acacia auriculiformis and Mangifera indica, as fuels. Results showed that only shrimp smoked using acacia charcoal in a chorkor kiln had PAH levels (benzo[a]pyrene = 5 µg kg^?1 and sum of benzo[a]pyrene, chrysene, benzo[a]anthracene and benzo[b]fluoranthene = 28 µg kg^?1) in accordance with a European standard of 5 and 30 µg kg^?1, respectively, and suitable physicochemical characteristics for good storage (moisture content = 11.9% ± 1.5%; water activity = 0.46 ± 0.03). However, further investigations still needs to be done to reduce the duration of product contact with combustion gasses in order to reduce the PAH content of smoked shrimp to safer levels, largely below standards.     

Headspace solid-phase microextraction as a tool to estimate the contamination of smoked cheeses by polycyclic aromatic hydrocarbons

Headspace solid-phase microextraction (HS-SPME) was used to study polycyclic aromatic hydrocarbons (PAH) in smoked cheeses. Two types of fiber coatings and different extraction conditions were tested. The results reveal that the use of an 85-microm polyacrylate fiber immersed in the headspace of the samples at 70 degrees C for 60 min is suitable for the detection of PAH with no more than 4 aromatic rings. To determine if a relationship can be established between the results obtained using a solvent extraction technique and HS-SPME, 6 samples of smoked cheese previously studied by a solvent extraction method were analyzed by HS-SPME, and the results obtained by both methodologies were compared. Polycyclic aromatic hydrocarbons were identified and quantified by gas chromatography-mass spectrometry operating in selective ion monitoring mode. Among the PAH determined by the solvent extraction method, only those with 4 aromatic rings or less were detected by HS-SPME and, consequently, this technique does not allow one to determine the PAH content of smoked cheese samples under the conditions of the study. Nevertheless, the relationship between the results obtained by both techniques for some PAH revealed that HS-SPME could be useful as a screening method to distinguish among samples with different degrees of PAH contamination.     

Influence of smoking parameters on the concentration of polycyclic aromatic hydrocarbons (PAHs) in Danish smoked fish

A new method for the analysis of 25 polycyclic aromatic hydrocarbon (PAH) compounds in fish was developed, validated, and used for the quantification of PAHs in 180 industrially smoked fish products. The method included pressurized liquid extraction, gel-permeation chromatography (Bio-beads S-X3), solid-phase extraction (silica gel), and gas chromatography-mass spectrometry analysis. The sum concentration of 25 PAHs (∑PAH₂₅) was highest in smoked herring (n = 3) and mackerel fillets (n = 13), with an average concentration of 320 and 235 µg kg^?1, respectively. Lowest average ∑PAH₂₅ concentrations were obtained for indirectly smoked trout (26 µg kg^?1). Principal component analysis was used to correlate processing parameters to PAH concentrations and to identify the effects of these parameters. The analysis showed that for salmon hot-smoking conditions lead to higher ΣPAH₂₅ than cold smoking, and for other fish species direct smoking leads to higher ΣPAH₂₅ than indirect smoking. Also, the usage of common alder increases the PAH contamination compared with beech. The effects of smoking time, combustion temperatures, and two types of smoke-generating material on the ∑PAH₂₅ were also tested in a pilot plant study with smoked trout as a model fish. In addition to confirming that increased combustion temperatures and usage of common alder in comparison with beech increased ∑PAH₂₅, it was also revealed that the PAH concentration decreased in the order fish skin ? outer layer of the fish muscle > inner part of the fish muscle.     

Reduction strategies for polycyclic aromatic hydrocarbons in processed foods

Polycyclic aromatic hydrocarbons (PAHs) are a large group of carcinogenic compounds. PAHs are ubiquitous in the environment and food, thus human beings may be exposed to PAHs through ingestion (water and food), inhalation (air and smoking), and skin contact in daily life. Dietary intake is the major source of exposure to PAHs in humans. Significant and harmful levels of PAHs can be generated during food processing and cooking. Although the formation of PAHs during processing is almost unavoidable, the levels can be diminished with reduction strategies. This review aims to provide comprehensive insights into the mechanisms underlying the formation of PAHs and factors influencing their formation in processed foods. The strategy for the reduction of PAHs including change in ingredients (i.e., reducing fat content), pretreatment conditions (i.e., reducing the pH), processing methods and parameters (i.e., reducing processing temperature and time), and packaging and storage conditions, are discussed. Potential novel strategies for PAH reduction are also identified and the feasibility is evaluated.     

高分子印迹固相萃取法测定熏烤肉制品中16 种欧盟优控多环芳烃

目的 建立高分子印记固相萃取-气相色谱质谱联用(MIPSPE-GC/MS)测定熏烤肉中 16 种欧盟优控多 环芳烃的检测方法。方法 样品经均质、超声波提取、高分子印记固相萃取柱净化后, 采用气相色谱质谱联用 仪在选择离子(SIM)扫描模式下进行测定, 内标法定量。 结果 本方法检出限为 0.07~0.24 μg/kg, 在 1~500 μg/L 范围内目标化合物具有很好的相关性, 相关系数均大于 0.999。日内及日间精密度小于 10%, 在 1、5 μg/kg 两 个加标水平下, 16 种 PAHs 回收率为 66.27 % ~ 111.61%, 相对标准偏差均小于 10%。 结论 本方法灵敏、 快速、 简便, 能满足熏烤肉制品中欧盟多环芳烃的检测要求。     

Contamination of cheese by polycyclic aromatic hydrocarbons in traditional smoking. Influence of the position in the smokehouse on the contamination level of smoked cheese

This paper sets out to determine the polycyclic aromatic hydrocarbon (PAH) contamination degree of a traditionally smoked cheese: Herreño cheese, which comes from one of the Canary Islands. Its PAH profile is thoroughly studied by means of gas chromatography-mass spectrometry in SIM mode, and compared with that of an unsmoked cheese. Furthermore, a parameter not previously studied is evaluated, namely the influence of the position of the individual cheeses in the smokehouse on their PAH contamination level. Heavy PAH, among which are included most of the carcinogens, are very scarce and their concentrations low. In fact, benz[a]anthracene, together with chrysene+triphenylene, are the only heavy PAH detected in all of the smoked samples studied. The concentration of benzo[a]pyrene, detected only in 1 of the samples, is below the limit established in Spain for the rind of smoked cheese. In contrast, high concentrations of light PAH have been found, especially of naphthalene and its alkyl derivatives, whose effect on human health is not yet well established. The results derived from the analysis of the PAH profile suggest the potential usefulness of certain ratios between some pairs of PAH (phenanthrene/anthracene, naphthalene/acenaphthylene) to provide information on the PAH contamination source. Furthermore, differences have been found, depending on the position of the cheeses in the smokehouse, those placed in the path followed by the smoke being more contaminated. Therefore, the findings of this study could help in improving the design of smokehouses, to decrease the PAH contamination degree of smoked cheese.     

Occurrence of polycyclic aromatic hydrocarbons in artisanal Palmero cheese smoked with two types of vegetable matter

Palmero cheese is a fresh smoked cheese from the Isle of Palma (Canary Islands), manufactured with goat's milk. To guarantee its safety, the occurrence of polycyclic aromatic hydrocarbons (PAH) in artisanal Palmero cheese smoked with 2 types of vegetable matter (almond shells and dry prickly pear) was studied. The determination of PAH includes extraction and clean-up steps, followed by separation, identification, and quantification of PAH by gas chromatography-mass spectrometry in selected ion-monitoring mode. The most abundant PAH are those with 2 and 3 aromatic rings. Although the highest total PAH concentrations corresponded to the cheeses smoked with almond shells, the degree of PAH contamination of the cheeses studied was lower than that found in other cheeses smoked in the traditional way. The nature of the vegetable material used for smoking seemed to have an influence on the type of PAH formed, especially on alkylderivatives and some light PAH. However, despite the artisanal, and consequently variable, production process of these cheeses, many similarities have been found among their PAH profiles. In fact, relatively constant relationships are observed between the concentrations of certain pairs of PAH. Benzo(a)pyrene was only present in 2 samples, and in much lower concentrations than the maximum allowed legal limits. Therefore, according to the results obtained, it appears that it is possible to obtain a safe product without renouncing the artisanal character or the sensory properties of this type of cheese.     

Determination of polycyclic aromatic hydrocarbons (PAHs) in commonly consumed Nigerian smoked/grilled fish and meat

Smoking and/or grilling, when carried out with traditional methods involving direct contact with wood combustion fumes, is responsible for high contamination levels with carcinogenic polycyclic aromatic hydrocarbons (PAHs). The aim of this work was to investigate the PAH content of different smoked or grilled meat and fish products commonly consumed in Nigeria. A rapid method involving microwave-assisted saponification and simultaneous extraction followed by solid-phase extraction (SPE), high-performance liquid chromatography (HPLC) separation and spectrofluorometric detection was employed. Samples that were smoked or grilled using traditional systems, which use a wood fire, were heavily contaminated with benzo[a]pyrene (BaP) at levels ranging from 2.4 to 31.2 µg kg^?1 wet weight. Considerably lower contamination levels were found in samples smoked or grilled in the laboratory using a charcoal fire (BaP from 0.7 to 2.8 µg kg^?1 wet weight). The health risk associated with a daily consumption of 100 g of these products was also evaluated using the margin of exposure (MOE) approach. MOE values lower than 10,000 were obtained for all smoked/grilled commercial samples, indicating a potential concern for consumer health.     

高风险食品中多环芳烃含量调查与分析

目的 通过对河北省11地市136份煎炸与熏烤食品中多环芳烃的（PAHs）含量的检测,考察不同食物种类、食物的来源渠道等因素对食品中PAHs含量的影响,。提示相关暴露风险。方法 样品经环己烷：乙酸乙酯(1:1, V:V)溶液超声提取后,通过凝胶色谱进行净化处理,采用高效液相色谱-荧光检测法进行检测。结果 市售的136份样品中, 均检出不同种类不同含量的PAHs, 检出率为100.0%,其中菲、蒽、荧蒽、芘及苯并(a)芘检出率较高;苯并(a)蒽、屈、苯并(b)荧蒽及苯并(k)荧蒽检出率相对较低。结论 高温、长时间反复使用的非正规散装食用油、直接使用明火煎炸与熏烤的食品中PAHs含量更高;正规厂家生产的此类食品中PAHs含量相对较低。     

焙炒条件对芝麻油中多环芳烃含量的影响

对芝麻进行不同条件焙炒实验,榨取芝麻油,之后对不同焙炒条件下芝麻油中多环芳烃含量进行检测分析。结果表明:随着焙炒时间的延长、焙炒温度的升高,芝麻油中B[a]P、PAH4、PAH16的含量都呈现明显上升趋势;对照国标GB 2716—2005及欧盟No835/2011号法规关于B[a]P和PAH4的限量,芝麻籽的合理焙炒时间不宜超过30 min,焙炒温度不宜超过200℃;焙炒时间为30 min的条件下,焙炒温度在200~240℃之间时,有利于3环物的积累,而焙炒温度达到260℃时,则有利于4环物及重质多环芳烃的积累。     

食品接触材料中多环芳烃在食品模拟物中的迁移规律研究

采用气相色谱-质谱联用法,对食品接触材料中多环芳烃在水、乙酸(体积分数为3%)、乙醇(体积分数为10%)和异辛烷等4种食品模拟物中的迁移规律进行了研究,研究迁移量与实验的温度、时间和模拟物属性等参数的关系。结果表明:模拟物的属性对迁移行为有显著影响,迁移量随温度的升高和时间的增加而变大。     

Determination of polycyclic aromatic hydrocarbons in smoked fishery products from different smoking kilns

The levels of 13 polycyclic aromatic hydrocarbons (PAH) were determined by an HPLC method with fluorescence and UV detection and by a GC/MS technique in smoked fishery products from modern smoking kilns with external smoke generation and from traditional smoking kilns. The average benzo(a)pyrene (BaP) concentration of all 35 samples from commercial smoking kilns with external smoke generation was 0.1 g/kg (wet weight) and the sum of the carcinogenic compounds determined in the study, i.e. benz(a)anthracene, chrysene, benzo(b)fluoranthene, benzo(k)fluoranthene, benzo(a)pyrene, dibenz(a,h)anthracene and indeno(1,2,3-c,d)pyrene did not exceed 4.5 g/kg (wet weight). The BaP levels of the 27 smoked fish samples from traditional kilns ranged from 0.2 g/kg to 4.1 g/kg, with a mean value of 1.2 g BaP/kg. The average concentration of the sum of the carcinogenic compounds was 9.0 g/kg. Large variations were found in the content of the non-carcinogenic PAHs phenanthrene, anthracene, fluoranthene and pyrene in all samples from both types of smoking kilns.     

气相色谱-质谱法测定醇食品模拟物中 16种多环芳烃

目的 建立固相微萃取-气相色谱-质谱联用仪测定醇食品模拟液中16种多环芳烃的分析方法。方法 优化了萃取方式、萃取温度、萃取时间、解吸时间和振荡速率等萃取条件, 样品采用气相色谱-质谱联用仪(gas chromatography-mass spectrometry, GC-MS)总离子流和选择离子模式进行定性定量测定。结果 16种多环芳烃在0.01~10 ?g/L范围内线性良好, R2大于0.99。在0.1、0.5、1.0 μg/L 3个添加水平下, 16种多环芳烃的平均回收率为76.52%?119.8%, 相对标准偏差为0.99%?15.93%。结论 该方法操作简便、灵敏度高、准确度好, 能够满足醇食品模拟物中多环芳烃化合物的检测要求。     

2015~2017年江苏省食品中多环芳烃污染状况的调查分析

目的 调查江苏省辖区内的食物中多环芳烃的污染水平现况。方法 收集2015~2017年江苏省13市区流通和餐饮环节的油炸食品、速食面、食用油类等样品, 采用高效液相色谱荧光检测器测定15种多环芳烃的含量。结果 采集5类食物共277份, 15种多环芳烃的检出率为18.8%, 各类食品中目标化合物检出含量范围: 油炸面类食品0.3~197.7 μg/kg; 速食面0.3~72.0 μg/kg; 食用油0.3~27.4 μg/kg; 果蔬类 0.1~2.56 μg/kg; 谷物0.1~6.92 μg/kg。苯并(a)芘(BaP)均未超标。结论 江苏省内食品中存在多环芳烃的污染状况, 15种多环芳烃的总含量的均值以油炸面类食品和食用油最高, 速食面次之, 谷物与果蔬类处于较低水平。     

Influence of different smoking techniques on contamination by polycyclic aromatic hydrocarbons in traditional smoked Mozzarella di Bufala Campana

The levels of six polycyclic aromatic hydrocarbons (PAHs) including benzo[a]pyrene and three other PAH were determined in smoked Mozzarella di Bufala Campana. Different smoking techniques were compared to evaluate the risk associated with consumption of these cheeses. Although no maximum limits are set for PAHs in cheese, the levels found in some samples constitute a health risk. In fact, using corrugated cardboard, high levels were detected in the whole product or in the outer part. Also, the use of traditional materials involves the accumulation of PAHs in the outer part, but in the total product concentrations are significantly lower. No contamination was found using liquid smoke.     

Reduction of the polycyclic aromatic hydrocarbon (PAH) content of charcoal smoke during grilling by charcoal preparation using high carbonisation and a preheating step

Charcoal-grilling may lead to contamination of food with carcinogenic polycyclic aromatic hydrocarbons (PAHs) during the grilling process. The objective of this work was to determine the effect of charcoal preparation on 16 USEPA priority PAHs in the smoke produced during the grilling process. Firstly, mangrove charcoal was prepared at carbonisation temperatures of 500, 750 and 1000°C. The charcoal were then preheated by burning at 650°C. This preheating step is usually used to prepare hot charcoal for the grilling process in the food industry. In this study, charcoal was preheated at different burning times at 5, 20 min and 5 h, at which time partial and whole charcoal glowed, and charcoal was completely burnt, respectively. Finally, PAHs in the smoke were collected and determined by GC/MS. The result showed that charcoal prepared at a carbonisation temperature of 500°C had higher levels of PAHs released into the smoke. In contrast, charcoal produced at 750 and 1000°C had lower PAHs released for all burning times. In addition, PAHs released for 5, 20 min and 5 h of burning time were about 19.9, 1.2 and 0.7 µg g^?1 dry charcoal for charcoal produced at 500°C, and about 0.9–1.4, 0.8–1.2 and 0.15–0.3 µg g^?1 dry charcoal for charcoal produced at 750 and 1000°C, respectively. Therefore, this research suggests that food grilled using charcoal carbonised at a high temperature of about 750°C presents a lower risk of PAH contamination. In addition, in the preheating step, whole charcoal should fully glow in order to reduce the PAH content in charcoal before grilling.     

Optimisation of microwave assisted extraction (MAE) for polycyclic aromatic hydrocarbon (PAH) determination in smoked meat

A rapid extraction method involving microwave assisted extraction (MAE), followed by sample clean-up on a silica cartridge, reversed-phase high performance liquid chromatography (RP-HPLC) and spectrofluorimetric detection, was optimised for polycyclic aromatic hydrocarbon (PAH) determination in smoked meat. Compared to solvent extraction assisted by sonication, MAE, carried out with n-hexane on 2g of lyophilised sample at 115°C for 15min, allowed to obtain better extraction efficiencies. Limits of quantification (LOQ, s/n=10) lower than 0.2μg/kg wet weight were found for all PAHs, except for Fl (0.3μg/kg), P (0.6μg/kg) and IP (0.4μg/kg). The optimised procedure, that presented good analytical performances (with recoveries ranging from 77% to 103%, and precision within 10% for most of the PAHs), was applied to determine PAH content in different smoked meat products from the Italian market.     

多环芳烃对农作物的影响及在食品中的来源、污染状况与检测分析

多环芳烃是一类持久性的有机污染物,对农作物的影响具有“双刃剑”效应,可对作物生长产生负面影响,也可起到提质增产的作用。该类物质具有致癌、致畸、致突变等毒性,广泛存在于食品、特别是烟熏食品中,过量摄入将严重危害人体健康。许多国家通过制定严格的限量标准、加强检验检测等措施对食品中的多环芳烃进行防控,但随着工业化的快速发展,煤、石油等燃料的大量使用,其食品污染问题依然突出,在食品中仍普遍被检出,已成为影响食品安全的主要风险来源之一,关于食品中多环芳烃的污染来源、监测分析和检测技术等方面的研究也日益增多。本文通过查阅近年来国内外发表的文献,概述了多环芳烃对农作物的影响,分析了食品中多环芳烃的来源和污染状况,从样品前处理和测定分析方面,综述了食品中多环芳烃的主要检测技术,评述了其优缺点,并提出了今后研究工作的建议,以期为同类研究提供参考。