Study of the components of a solid smoke flavouring preparation

The study of the components of a solid smoke flavouring preparation was carried out using several techniques. The sample was extracted by means of an ultrasonic bath and by successively using dichloromethane and water as solvents. Observation by microscope, of the initial sample and the residues of extractions, indicate that the carrier of this preparation consists of two components insoluble in dichloromethane. One of these consist of small transparent globular particles, and the other of irregular particles of a gold colour, the latter is soluble in water. Fourier Transform infra-red spectra of the solid smoke flavouring preparation, its extracts and residues, were obtained and studied. From these it can be concluded that the two components of the carrier are saccharides, one of them similar to starch and the other with reducing ability owing to the presence of carbonyl groups. Also, from the infra-red spectrum of the flavouring mixture extracted with dichloromethane, ratios between the absorbances of carbonyl and phenol functional groups are obtained, and compared with those of an aqueous smoke flavouring. Finally, the composition of the volatile fraction of the extract in dichloromethane was studied by gas chromatography-mass spectrometry and gas chromatography techniques. Carbonyl compounds, namely ketones, aldehydes, and furan and pyran derivatives, are the major components and constitute approximately 60% of the volatile fraction of the extract. Also, phenol derivatives are present in the sample. Guaiacol and syringol derivatives constitute approximately 25% of the volatile fraction. Some compounds, not previously detected in wood smoke, were identified in this flavouring. However, polycyclic aromatic hydrocarbons were not detected in the sample. Quantitative data from gas chromatography and infrared spectroscopy agree, and show the close relationship between the composition of the soluble fraction in dichloromethane and the odour of the sample.     

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.     

Polycyclic aromatic hydrocarbons in meat smoked with different types of wood

The influence of the wood used for the smoking of meat on the formation of polycyclic aromatic hydrocarbons (PAH) has been studied. Ten types of wood and charcoal were used for preparation of smoked meat samples. The analytical sample preparation method implied extraction of PAH with cyclohexane, liquid–liquid extraction with N,N-dimethylformamide/water, back extraction with cyclohexane, followed by clean-up on silica solid phase extraction (SPE) column and quantification by gas chromatography–mass spectrometry. It was found that the type of wood has a significant influence on the amount of PAH in smoked meat. The samples smoked with apple-tree and alder contained the smallest PAH concentrations. The samples smoked with spruce had the highest concentrations of PAH. The difference in content of benzo[a]pyrene (from 6.04 till 35.07 μg/kg) and total PAH (from 47.94 till 470.91 μg/kg) indicates that choice of wood for smoking is one of the critical parameter to be controlled in order to diminish the contamination of food products.     

Determination of polycyclic aromatic hydrocarbons (PAH) in edible vegetable oils by liquid chromatography and programmed fluorescence detection. Comparison of caffeine complexation and XAD-2 chromatography sample clean-up

Two clean-up procedures were compared for the analysis for polycyclic aromatic hydrocarbons (PAHs) in edible vegetable oils. One method comprises a liquid-liquid extraction followed by XAD-2 chromatography and the other a caffeine-formic acid complexation. The clean-up step is followed by gradient reversed-phase HPLC in combination with wavelength-programmed fluorescence detection. Due to better repeatability and simplicity, the XAD-2 method was selected for the determination of PAHs in 14 different vegetable oils. Between the different oil samples large differences were observed in PAH concentrations. PAH concentrations in vegetable oils sampled from the Dutch market appear to be comparable with those found in other countries.     

GC/MS analysis of lignin monomers,dimers and trimers in liquid smoke flavourings

The common components found in smoke flavourings are carbonyl derivatives, acids, esters and lignin monomers such as alkyl-aryl ethers and phenol derivatives. Recently the presence of lignin dimers has been noted. In addition to these compounds, lignin trimers and new lignin dimers have been detected in the brown layer left by a smoke flavouring on the wall of the receptacle in which it was contained; these compounds tend to migrate towards the wall of the container and have not been previously described as smoke or smoke flavouring components. Lignin trimers and dimers are important in the preservation of smoked foods for their known high antioxidant activity, even higher than that of the lignin monomers. The mass spectral data of a large number of lignin trimers and dimers are given and can be useful for future studies of smoke flavourings and smoked food as well as in beverage studies and for the characterisation of woods to be used in the beverage industry. © 1999 Society of Chemical Industry     

Polycyclic aromatic hydrocarbons in smoked fish – a critical review

Among hundreds of components, wood smoke also contains at least 100 polycyclic aromatic hydrocarbons (PAH) and their alkylated derivatives. Many of them are carcinogenic. Benzo[α]pyrene (BaP) is regarded as a marker of the carcinogenic PAH in smoke and smoked fish, although in olive residual oil the maximum level of 2 μg/kg for each of the eight most carcinogenic PAHs, including BaP, has been set. Contemporary analytical procedures based on extraction of the hydrocarbons from the matrix, clean-up procedure, separation by gas chromatography (GC) or high performance liquid chromatography (HPLC), followed by detection and quantification by mass spectrometry (MS) or fluorescence detectors (FLD), respectively, make it possible to determine individual PAH in smoked foods at concentrations of the order of 0.1 μg/kg or even 0.01 μg/kg. Heavily smoked fish from traditional kilns, especially their outer parts, may contain up to about 50 μg BaP/kg wet weight, while the meat of mild hot-smoked fish, from smokehouses supplied with conditioned wood smoke from external generators, contains only about 0.1 μg/kg, or even less. Some older data on the contents of BaP in smoked fish should be treated with caution, if the analytical procedures used did not guarantee unequivocal separation and identification of the individual PAH.     

正交试验优化蔬菜中多环芳烃检测前处理工艺

本实验以叶用莴苣(Lactuca sativa L.)叶片鲜样匀浆为试材,优化蔬菜体内多环芳烃检测前处理工艺。通过单因素实验确定样品质量、提取液体积、超声提取时间、硫酸体积、硫酸浓度、洗脱液配比六个因素的实验条件范围,再利用正交试验,优化前处理工艺。结果表明:最佳前处理方案为提取液体积52 mL、样品质量14 g、超声波提取时间38 min、硫酸体积13 mL、硫酸浓度35%、洗脱液类型6 mL正己烷和6 mL二氯甲烷/正己烷(V₁:V₂=3:7),在此条件下测得莴苣体内PAHs含量最高为961.541 μg/kg;此条件加标回收率为80.54%~142.04%,RSDs为1.35%~8.96%,具有较好的准确度和精密度。该前处理工艺具有样品制备简单、适合大量样品检测、实验结果重复性好等优点,可应用于蔬菜中PAHs提取。     

复合添加剂降低卷烟烟气中多种致癌物研究

为研究降低卷烟烟气中多种致癌物的方法 ,从羊齿类天然植物中提取出多种酮、酚类及其衍生物组合得到复合添加剂 ,以 0 0 0 8%的比例添加于卷烟滤嘴或烟丝中。检测结果表明 ,在卷烟中添加该复合添加剂后 ,其主流烟气中的多种稠环芳烃、自由基和芳香胺等致癌物的含量显著降低 ,对烟气中烟草特有亚硝胺也有一定的清除作用。     

供体受体复合色谱法测定植物油中16种欧盟优控多环芳烃

欧盟推荐检测16种具有基因毒性和致癌性的多环芳烃.为了检测植物油中这16种物质,建立了供体受体复合色谱(DACC)净化、高效液相色谱紫外/荧光检测器(HPLC - UV/FLD)定量测定方法.试验证明此法可有效分离植物油中的这16种物质,减少了溶剂用量,节约了分析时间.     

醋纤和改性丙纤滤嘴过滤卷烟烟气有害成分效果比较

选用由醋酸纤维丝束和改性聚丙烯纤维丝束两种不同材料滤嘴卷制成的同一牌号卷烟,研究了两种不同材料滤嘴对卷烟烟气中特有亚硝胺、芳香胺、酚类、多环芳烃、氨以及挥发性羰基化合物等有害成分的过滤效果。结果表明:对多环芳烃,改性丙纤滤嘴的过滤效率高于醋纤滤嘴;对芳香胺、烟草特有亚硝胺、挥发性羰基化合物和酚类化合物,两种滤嘴的过滤效率接近,醋纤滤嘴的过滤效率略高于改性丙纤滤嘴;对烟气中的氨,醋纤滤嘴的过滤效率高于改性丙纤滤嘴。     

烟熏液及其在肉制品中的应用研究进展

烟熏作为一种食品保藏技术应用于肉制品中已经有很长的历史。传统烟熏方法熏制过程复杂,污染环境,熏制的肉制品含有苯并芘等致癌多环芳烃且不美观。烟熏液作为传统烟熏的替代品,使用起来更加方便,对环境无污染,且产品中无3,4-苯并芘等致癌物。本文主要综述国内外对烟熏液及其在肉制品生产中的应用现状,以期为烟熏液的研究及其在未来食品工业中的推广应用提供参考。     

Phenolic antioxidants in alder smoke during industrial meat curing

Alder wood smoke in a large sausage-curing chamber was analysed with regard to its content of methoxyphenol antioxidants. The use of Tenax adsorbent cartridges permitted simultaneous quantitative sampling of phenols condensed on smoke particles as well as gaseous compounds. The analytical determinations were performed by thermal desorption combined with gas chromatography and mass spectrometry. In addition to methoxyphenols, several other key components were assessed, including 1,6-anhydroglucose, 2-furaldehyde, furans and hydrocarbons. Benzene was the most prominent hydrocarbon. The concentrations of polycyclic aromatic compounds were low, due to a low smoke generation temperature. Predominant smoke components were the 2,6-dimethoxyphenols, which are characteristic thermal degradation products from hardwood. The 2,6-dimethoxyphenols are stronger antioxidants than the 2-methoxyphenols present in lower amounts. The particularly active antioxidants with a 4-alkenyl side-chain constituted 20–30% of total methoxyphenols, which is much more than normally reported for liquid smoke. The phenolic antioxidants may be important not only for the preservation of foods, but also for health as dietary components.     

The effect of natural and liquid smokes on the benzo[a] pyrene content and quality parameters of Circassian cheese

The objective of this study was to determine the effects of natural smoke and liquid smoke application methods on quality characteristics of smoked Circassian cheese. The microbial counts of liquid smoked cheeses were found to be higher than naturally smoked cheeses. It can be concluded that although natural smoke inhibited the growth of micro‐organisms more than liquid smoke application, benzo[a]pyrene, an indicator component for polycyclic aromatic hydrocarbons (PAH), was detected on the outer surface of naturally smoked cheeses. Therefore, liquid smoking could be used as an alternative method for smoked Circassian cheese production.     

Simultaneous formation of polycyclic aromatic hydrocarbons (PAHs) and heterocyclic aromatic amines (HCAs) in gas-grilled beef satay at different temperatures

This study investigated the simultaneous formation of polycyclic aromatic hydrocarbons (PAHs) and heterocyclic aromatic amines (HCAs) in gas-grilled beef satay at different temperatures (150, 200, 250, 300, and 350°C). Solid-phase extraction (SPE) was used for sample clean-up. Fifteen PAHs were determined using high performance liquid chromatography with fluorescence detection (HPLC-FLD) and nine HCAs were quantified using liquid chromatography tandem-mass spectrometry (LC-MS/MS) with a gradient programme. The lowest significantly concentrations of PAHs and HCAs were generated at 150°C; the formation of PAHs and HCAs simultaneously increased with temperatures. Benzo[a]pyrene was detected in all samples and increased markedly at 300 and 350°C. The sums of 4 PAHs (PAH4) in marinated beef satay at 300 and 350°C exceeded the maximum level in Commission Regulation (EU) 2015/1125. Significant reductions of polar and non-polar HCAs (except PhIP) were found in marinated beef satay across all temperatures. Overall, PAHs and HCAs showed opposite trends of formation in beef satay with marination.     

Optimisation and validation of an HPLC method for determination of polycyclic aromatic hydrocarbons (PAHs) in mussels

A method for determination of 11 polycyclic aromatic hydrocarbons (PAHs) in mussels (Mytilus galloprovincialis), using HPLC coupled to a fluorescence detector, has been optimised and validated, according to European Community rules. Sample preparation involves alkaline digestion of mussel tissue, liquid–liquid extraction of organic compounds and solid phase clean-up. Accuracy and precision of the method were determined by a validation study, carried out to demonstrate that the method is useful for both screening purposes and confirmation. Commission Regulation (EC) No. 2007/333/EC stated the performance criteria for the analysis of the only benzo[a]pyrene (BaP) in food products of animal origin, since BaP is the most studied PAH. We extended the BaP analysis performance criteria to other 10 toxic PAHs (listed in Commission Recommendation (EC) No. 2005/108/EC) and the validation study was performed also in agreement with Commission Decision (EC) No. 2002/657/EC. The method was applied to investigate 27 mussel samples from actively producing shellfish plants located in Campania (Italy) and variable levels of PAHs were detected ranging from <0.2 to 16 μg/kg wet weight.     

Smoke and liquid smoke. Study of an aqueous smoke flavouring from the aromatic plant Thymus vulgaris L

An aqueous smoke flavouring from Thymus vulgaris L was obtained. The qualitative and quantitative composition of its dichloromethane extract was studied by gas chromatography and gas chromatography/mass spectrometry. In addition to the common smoke components such as aldehydes, ketones, diketones, esters, acids, furan and pyran derivatives, alkyl aryl ethers, phenol, guaiacol and syringol derivatives, some terpenic compounds were detected. Differences between this aqueous liquid smoke and others from various kinds of wood are due not only to the absence or presence of some compounds but also to the proportions of the different groups of components present in the mixture. Some aldehydes, esters, guaiacol and its derivatives and terpenic compounds contribute to the overall odour of this liquid smoke more significantly than the ketones, furan and pyran derivatives, acids, phenol and its derivatives and syringol. The yield in smoke components obtained from the pyrolysis of Thymus vulgaris L at 488 °C is of a similar order to that obtained from other woods. © 1999 Society of Chemical Industry     

热反应肉香风味调味料

介绍了肉香风味调味料的开发历程，论述了热反应肉香风味调味料的天然性、高科技性及其调味功能，最后介绍了热反应肉香风味调味料在方便面中的应用。     

HPLC-fluorescence analysis of polycyclic aromatic hydrocarbons (PAHs) in pork meat and its gravy fried without additives and in the presence of onion and garlic

The effect of onion and garlic on the formation of polycyclic aromatic hydrocarbons (PAHs) was evaluated by comparing the concentrations of PAHs in meat and gravy samples coming from pork dishes prepared in the presence and absence of these spices. PAHs were analysed by high performance liquid chromatography with fluorescence detection. The clean-up procedure included alkaline hydrolysis, solid-phase extraction (on columns with diatomaceous earth and propyl sulphonic acid) and column chromatography on silica gel. Total concentrations of 6 PAHs (benzo[b]fluoranthne, benzo[k]fluoranthne, benzo[a]anthracene, benzo[a]pyrene, dibenzo[a,h]anthracene, benzo[g,h,i]perylene) were (in ng g⁻¹ of cooked meat) from 2.0 to 7.2 in meat samples and from 0.05 to 0.6 in gravies. Concentration of B[a]P was from 0.38 to 1.61 in meat and from 0.01 to 0.11 in gravy samples. Onion (30/100 g of meat) caused on average decrease of 60% of the total content of PAHs in pan fried meat and of over 90% in gravies. Garlic (15/100 g of meat) lowered the concentration of 54% in meat on average and from 13.5–79% in gravies.     

Determination of polycyclic aromatic hydrocarbons in edible oils and barbecued food by HPLC/UV–Vis detection

Determination of nine polycyclic aromatic hydrocarbons in corn, sunflower, olive oils and barbecued meat and fish by HPLC/UV–Vis method is described. The extraction procedure included a saponification, liquid–liquid extraction and finally purification of PAHs through a house-made silica–alumina column. Chromatographic determination was based on separation of PAHs on ODS column and measurement at 254 nm. All polycyclic aromatic hydrocarbons were separated and analyzed in 12 min on reversed phase ODS column with acetonitrile/water mobile phase at 1.5 mL min⁻¹ flow rate. The detection limits of nine polycyclic aromatic hydrocarbons ranged from 0.26 to 1.15 μg L⁻¹ at a signal/noise ratio of 3. The linearity of the method was between 0.9951 and 0.9996. Oil samples contain different PAHs ranging from 0.44 to 98.92 μg L⁻¹. Barbecuing process increased the concentration (in the range of 2- to 8-fold) and caused the formation of PAHs in food samples.     

Determination of Polycyclic Aromatic Hydrocarbons in Seafood

The aim of this project is to determine polycyclic aromatic hydrocarbons (PAHs) in several seafood matrices, i.e., fish, and mussel, by the use of comprehensive two-dimensional gas chromatography-quadrupole mass spectrometry (GCXGC-MS). The procedure involves a simple extraction of PAHs, a filtration and concentration step followed by GCXGC-MS analysis. PAHs were determined in fish tissue samples by GCXGC-MS and by a standard high-pressure liquid chromatography fluorescence detector method. A Bland–Altman analysis of the two methods was performed. It indicated equivalence between the two methods. Analysis of mussel tissue (National Institute of Standards and Technology (NIST)-SRM 2974a) was performed. The results were in line with the official results of NIST.