Extraction of polycyclic aromatic hydrocarbons from cookies: A comparative study of ultrasound and microwave-assisted procedures

The chromatographic determination of 15 polycyclic aromatic hydrocarbons (PAHs) in cookies has been improved in order to obtain a fast method with a low limit of detection through the combination of microwave-assisted extraction (MAE), oil saponification and solid-phase extraction clean-up before the injection of purified extracts in a C18 201TP52 (5 µm, 250  × 2.1 mm) column. Using acetonitrile-water as mobile phase, with a 50% to 95% w/w acetonitrile gradient for a fixed flow of 0.250 ml min^-1, 15 PAHs were separated in 45 min. The column temperature was maintained at 15°C; and fluorimetric detection was made at a fixed excitation wavelength of 264 nm and emission measurements at the best wavelength for each analyte, from 352 nm for 11H-benzo[b]fluorene to 500 nm for indeno[1,2,3-c,d]pyrene. Recoveries for all 15 PAHs varied between 96  ± 4 and 105%  ± 4%; and the limits of detection ranged from 0.015 ng g^-1 for chrysene to 0.7 ng g^-1 for phenantrene. Results were compared with those obtained by conventional Soxhlet extraction during 8-h refluxing with toluene, demonstrating that the methodology proposed is appropriate to quantify PAHs in cookies. Furthermore, the microwave-assisted method was faster and used less solvent than the conventional and ultrasound-assisted methods. The extraction time was reduced to 9 min compared with the 8 h required for Soxhlet extraction and 60 min required for ultrasound-assisted treatment, and the solvent consumption has been reduced to 25 ml compared with the 155 and 90 ml required using Soxhlet and ultrasound, respectively.     

Optimization and validation of an extraction method for the analysis of polycyclic aromatic hydrocarbons in chocolate candies

Abstract: Chocolate is a key ingredient in many foods such as milk shakes, candies, bars, cookies, and cereals. Chocolate candies are often consumed by mankind of all age groups. The presence of polycyclic aromatic hydrocarbons (PAHs) in chocolate candies may result in health risk to people. A rapid, precise, and economic extraction method was optimized and validated for the simultaneous determination of polycyclic aromatic hydrocarbons in chocolate candy by high‐performance liquid chromatography (HPLC) and gas chromatography‐mass spectrometry (GS‐MS) as a confirmatory technique. The method was optimized by using different solvents for liquid–liquid extraction, varying volume of de‐emulsifying agent, and quantity of silica gel used for purification. The HPLC separation of 16 PAHs was carried out by C‐18 column with mobile phase composed of acetonitrile : water (70 : 30) in isocratic mode with runtime of 20 min. Limit of detection, limit of quantification (LOQ), and correlation coefficients were found in the range of 0.3 to 4ng g^?1, 0.9 to 12ng g^?1, and 0.9109 to 0.9952, respectively. The exploration of 25 local chocolate candy samples for the presence of PAHs showed the mean content of benzo[a]pyrene as 1.62 ng g^?1, which representing the need to evaluate effective measures to prevent more severe PAHs contamination in chocolate candies in future. Practical Application: Chocolate is one of the most favorite food items among people, especially children. Chocolate candies are often consumed by mankind of all age groups. Chocolate candies are often consumed by children in large quantities. The presence PAHs in chocolate candies may result in health risk to people. In the present study, a precise and cost effective rapid method was employed for the determination of PAHs, which can be employed for daily routine analysis of PAHs in chocolate products.     

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.     

Characterization of Valuable Compounds from Winter Melon (<Emphasis Type="Italic">Benincasa hispida</Emphasis> (Thunb.) Cogn.) Seeds Using Supercritical Carbon Dioxide Extraction Combined with Pressure Swing Technique

In this study, we describe the extraction of different valuable compounds from winter melon seeds using supercritical carbon dioxide extraction combined with pressure swing technique (SCE-PST). The effects of the extraction variables, namely pressure, holding time (HT), and continuous extraction time (CT), were optimized by response surface methodology (RSM) to maximize the crude extraction yield (CEY). The optimal conditions were at pressure of 181.35 bar, HT of 9.93 min, and CT of 50.14 min. Under these conditions, the experimental CEY was 235.70?±?0.11 mg g^?1 with a relatively strong antioxidant activity (64.42?±?0.21 % inhibition of DPPH^· radicals, 67.36?±?0.34 % inhibition of ABTS^·+ radicals) and considerable amount of phenolic compounds (42.77?±?0.40 mg gallic acid equivalent/g extract). The high-performance liquid chromatography (HPLC) analysis revealed that the bioactive phenolic compounds increased significantly using PST (p?<?0.05), where gallic acid had the highest concentration (0.688?±?0.34 mg g^?1). The extract obtained using optimal SCE-PST conditions contained more than 83.65 % total unsaturated fatty acids (UFAs) and linoleic acid accounted for 67.33?±?0.22 % in the total extract. From the results, the SCE efficiency in terms of extract quantity and quality has been enhanced significantly applying PST. Finally, the results were compared with previous published findings using supercritical carbon dioxide, ultrasound-assisted, and Soxhlet extraction. It was found that higher CEY could be achieved using Soxhlet extraction even through the quality of SCE-PST extracts in terms of antioxidant activity and phenolic compounds was better.     

Quantitative HPLC Analysis of Benzene Derivatives of Melicope Ptelefolia Leaves

A high performance liquid chromatography procedure for the quantitative determination of three marker benzene derivatives, 2,4,6-trihydroxy-3-prenyl acetophenone (tHPA) (1), 2,4,6-trihydroxy-3-geranyl acetophenone (tHGA) (2), and p-O-geranyl coumaric acid (GCA) (3), in the Melicope ptelefolia ethanolic leaf extracts, a medicinal herb obtained from a few locations of the Peninsula Malaysia, was described. The quantitative analysis was performed using high performance liquid chromatography-photodiode array detection on Xterra octadecylsiyl silica (ODS; 3.0?×?150 mm, 3.5 μm) column kept at 32°C, using gradient elution with acetonitrile and water containing 0.1% formic acid at a flow-rate of 1 ml/min with UV detection wavelength at 280 nm. All calibration curves showed good linearity (R² of 0.999 to 1.0000) within the concentrations range of 2.5?×?10^?3 to 0.1 mg/mL. The method was shown to be simple, sensitive, and reliable for qualitative and quantitative analysis of the marker compounds in M. ptelefolia leaf preparations.     

Development of a screening analytical method for the determination of non-dioxin-like polychlorinated biphenyls in chicken eggs by gaschromatography and electron capture detection

ABSTRACT

A sensitive and reproducible screening analytical method is here proposed for the determination of six non dioxin-like polychlorinated biphenyls (NDL-PCBs, congener 28, 52, 101, 138, 153, 180) in chicken eggs based on accelerated solvent extraction (ASE) procedure for the fat extraction and determination, a solid phase extraction (SPE) sample clean-up process, and a gas chromatography – electron capture detection (GC-ECD) analysis. The optimized chromatographic separation, in less than 25 min, returned good responses for the six NDL-PCBs in the range of 2.5–60.0 µg L^?1, with correlation coefficients always higher than 0.9995. Instrumental limits of detection were between 0.08–0.35 µg L^?1, corresponding to 0.05 and 0.23 ng g^?1 fat in the matrix, while method detection limits, calculated on spiked egg samples, ranged from 1.6 to 3.5 ng g^?1 fat. The method has been extensively validated in terms of selectivity, sensitivity, recovery, precision, ruggedness and measurement uncertainty, following the European Directives.     

Simultaneous Determination of Seven Polycyclic Aromatic Hydrocarbons in Coffee Samples Using Effective Microwave-Assisted Extraction and Microextraction Method Followed by Gas Chromatography-Mass Spectrometry and Method Optimization Using Central Composite Design

In this research, for the first attempt, we successfully determined seven polycyclic aromatic hydrocarbons (PAHs) in various coffee samples using microwave-assisted extraction and dispersive liquid-liquid microextraction (MAE-DLLME) coupled with gas chromatography-mass spectrometry (GC-MS). The effects of most important variables in microextraction step were investigated and optimized using response surface methodology (RSM) based on central composite design. The calibration curves were linear in the range of 1–200 ng g^?1, with a correlation coefficient (R ²) higher than 0.989. Limits of detection were obtained between 0.1 and 0.3 ng g^?1. The relative standard deviations (RSD%) for seven repeated analysis were less than 8% for all PAH compounds at a concentration of 10 ng g^?1. Relative recoveries were obtained 88.1–101.3%. The satisfactory results obtained by the proposed method and the comparison of these results with previous methods demonstrated that the MAE-DLLME-GC-MS is an accurate, rapid, and reliable sample-pretreatment method with low consumption of the organic solvent.     

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.     

Multivariate optimisation of an ultrasound assisted-matrix solid-phase dispersion method combined with LC-fluorescence detection for simultaneous extraction and determination of aflatoxins in pistachio nut samples

This paper describes the application of ultrasound-assisted matrix solid-phase dispersion as an extraction and clean-up procedure for aflatoxins (B₁, B₂, G₁ and G₂) and subsequent determination by LC-fluorescence detection. A Box–Behnken design was used to determine the parameters influencing the extraction procedure through response surface methodology and experimental design. The influence of different variables including type of dispersing phase, sample-to-dispersing phase ratio, type and quantity of clean-up phase, ultrasonication time, ultrasonication temperature, nature and volume of the elution solvent were investigated in the optimisation study. C18, graphitic carbon black and acetonitrile were selected as dispersing phase, clean-up phase and elution solvent, respectively. The optimised values were sample-to-dispersing phase ratio of 1:1, 50 mg of graphitic carbon black, 11 min ultrasonication time, 30°C ultrasonication temperature and 3 ml acetonitrile. Under the optimal conditions the limits of detection (LODs) were ranged from 0.04–0.11 µg kg^?1 and the relative standard deviations (RSDs) of the extraction method were less than 8.6%. The recoveries of the matrix solid-phase dispersion process ranged from 74% to 78% with relative standard deviation lower than 9% in all cases. Finally, the matrix solid-phase dispersion was successfully applied to extraction of trace amounts of aflatoxins in pistachio samples.     

Ultrasound and microwave assisted extraction of diosgenin from fenugreek seed and fenugreek-supplemented cookies

Fenugreek has been recognized as the most important medicinal plant. The presence of diosgenin in fenugreek seed is known to have promising health benefits. In the present work the extraction of diosgenin from the fenugreek seed was performed and its supplementation in cookies was done. The ultrasound-assisted extraction (UAE) and microwave-assisted extraction (MAE) methods have been applied for extraction of diosgenin. In case of UAE, the maximum diosgenin was obtained from fenugreek seed powder with 80 % ethanol solution for 50 min, whereas the maximum diosgenin in MAE was obtained at 80 % ethanol solution for 4 min. Overall, the extract yield of UAE was higher than MAE. The UAE method with an ethanolic concentration of 80 % was considered as optimum for the determination of diosgenin in cookies. The diosgenin content of the cookies supplemented with fenugreek seed powder increased with its increase and the diosgenin content ranged from 0.099 to 0.191 g diosgenin equivalent/100 g of cookies. Further research on the incorporation of fenugreek seed powder and diosgenin in ready-to-eat foods are of great value because of health benefits of diosgenin and market demand of ready-to-eat foods.     

Single-laboratory validation of a saponification method for the determination of four polycyclic aromatic hydrocarbons in edible oils by HPLC-fluorescence detection

An analytical method is reported for the determination of four polycyclic aromatic hydrocarbons (benzo[a]pyrene (BaP), benz[a]anthracene (BaA), benzo[b]fluoranthene (BbF) and chrysene (CHR)) in edible oils (sesame, maize, sunflower and olive oil) by high-performance liquid chromatography. Sample preparation is based on three steps including saponification, liquid–liquid partitioning and, finally, clean-up by solid phase extraction on 2 g of silica. Guidance on single-laboratory validation of the proposed analysis method was taken from the second edition of the Eurachem guide on method validation. The lower level of the working range of the method was determined by the limits of quantification of the individual analytes, and the upper level was equal to 5.0 µg kg^?1. The limits of detection and quantification of the four PAHs ranged from 0.06 to 0.12 µg kg^?1 and from 0.13 to 0.24 µg kg^?1. Recoveries of more than 84.8% were achieved for all four PAHs at two concentration levels (2.5 and 5.0 µg kg^?1), and expanded relative measurement uncertainties were below 20%. The performance of the validated method was in all aspects compliant with provisions set in European Union legislation for the performance of analytical methods employed in the official control of food. The applicability of the method to routine samples was evaluated based on a limited number of commercial edible oil samples.     

Sequential Microwave-Ultrasound-Assisted Extraction for Isolation of Piperine from Black Pepper (<Emphasis Type="Italic">Piper nigrum</Emphasis> L.)

Piperine is the natural bioactive component of black pepper (Piper nigrum L.) with several astounding therapeutic properties. In this study, sequential microwave-ultrasound-assisted extraction approach was used for isolation of piperine from black pepper. The effect of various factors such as extraction solvent, particle size of pepper, solvent to solid ratio, microwave power and time and ultrasound temperature and time on the extraction yield of piperine was considered. The maximum extraction yield was 46.6 mg piperine/g pepper which was obtained using ethanol as solvent at the particle size of 0.15 mm, solvent to solid ratio of 20:1, microwave power of 100 W for 1 min, and ultrasound temperature of 50 ^° C for 30 min. This extraction yield was higher than those obtained by Soxhlet (39.1 mg/g), microwave-assisted (38.8 mg/g) and ultrasound-assisted (37.0 mg/g) extractions. The purity of the extracted piperine was 81.4% as determined by HPLC analysis. The FTIR and UV-vis analyses confirmed that the structure of piperine remained intact after extraction and purification which is very important for medicinal applications.     

Polycyclic aromatic hydrocarbons in smoked cheese

BACKGROUND: Polycyclic aromatic hydrocarbons (PAHs) represent a group of organic compounds containing two or more aromatic rings. Their control in the human food chain is required due to the mutagenic and carcinogenic potential, exhibited in vertebrates. In the present study, the occurrence of PAHs in 36 cheeses smoked by various processes was investigated. RESULTS: PAH concentrations (sum of 15 US EPA PAHs) found in samples smoked under controlled industrial conditions were at level 0.11 µg kg^?1, whereas in ‘home‐made’ cheeses, the PAH content was up to 10 times higher. A similar trend was observed for B[a]P, a marker compound representing carcinogenic PAHs. While its levels in commercial products prepared by controlled smoking technologies were close to the limit of quantification (0.03 µg kg^?1); in household samples, the B[a]P content ranged from 0.6 to 0.9 µg kg^?1. Significantly higher amounts of PAHs (up to three to six times) were found in surface layers as compared to internal parts of cheese. CONCLUSION: Although smoked cheese is a popular food, only several papers have focused on PAH levels in these products. This paper evaluates the contribution of different smoking technologies to PAH contamination of several cheeses and thus can help in a risk assessment associated with their consumption. Moreover, the study shows the concentration ratios of selected PAHs, from which the type of smoking technology can be indicated. The results obtained in this study also supported the suggestion of the EU Scientific Committee on Food to use benzo[a]pyrene as an indicator of the occurrence of higher‐molecular mass PAHs. Copyright © 2008 Society of Chemical Industry     

Stability of the mycotoxin deoxynivalenol (DON) during the production of flour-based foods and wheat flake cereal

Deoxynivalenol (DON) is a mycotoxin found in cereal grains and cereal-based foods. DON concentrations in finished products are reduced under some processing conditions, but not others. DON concentrations in flour, wheat and selected foods made from them under commercially relevant conditions were compared by GC with electron capture detection. Average concentrations (n?=?9/item) in cookies, crackers and pretzels ranged from 61% (cookies) to 111% (pretzels) compared with flour (100%?=?0.46?µg?g^?1). Lesser amounts were found in donuts and bread: their respective DON concentrations were 44% and 30% that of flour. Mass balance estimates for DON (µg?g^?1 flour equivalents) ranged from 50% (bread?=?0.23?µg?g^?1 flour equivalents) to 120% (donuts), indicating that dilution by recipe ingredients contributed to DON reductions in bread and accounted for all of the apparent reduction in donuts. Mass balance estimates averaged 76% (crackers) to 107% (pretzels) for the other flour products. DON concentrations were higher in cereal flakes (0.55?µg?g^?1 in the finished product and 0.58?µg?g^?1 on a mass balance basis) than in wheat (0.40?µg?g^?1), suggesting that DON concentrations might increase during processing of wheat cereals under some conditions. In summary, DON concentrations of finished food products were reduced?≥50% only in bread and donuts. Reduction in bread resulted from a combination of DON ‘loss’ and dilution by recipe ingredients whereas the reduction in donuts was due entirely to dilution. These results are further evidence of DON stability during the preparation of popular flour or wheat-based products.     

Determination of Polycyclic Aromatic Hydrocarbons (PAHs) in Olive and Refined Pomace Olive Oils with Modified Low Temperature and Ultrasound-Assisted Liquid–Liquid Extraction Method Followed by the HPLC/FLD

The cleanup method of modified low temperature was compared with the standardized method of modified ultrasound-assisted liquid–liquid (UALL) extraction for the analysis of 15 polycyclic aromatic hydrocarbons (PAHs) in olive oil and refined pomace olive oil. The modified UALL extraction consisted in purification on C₁₈ reversed-phase, Florisil-bonded-phase and NH₂ cartridges, and modified low-temperature extraction was followed by alumina-N and NH₂ solid-phase extraction (SPE) cartridges. Both methods are followed by reversed-phase high-performance liquid chromatography with fluorescence detection. The chromatograms of the final extracts showed lower interferences in both of the methods. The solvent consumption and cost for the modified UALL method were higher than those of the modified low temperature, and also, it needed more equipment, but its analysis time was less. The limit of detection and limit of quantitation of the modified UALL method were 0.16–0.97 and 0.57–2.93 μg kg^?1, respectively, and for the modified low temperature, they were 0.09–1.97 and 0.29–5.99 μg kg^?1, respectively. The PAH recoveries for the modified UALL extraction method ranged from 75.0 to 111.0 % (RSD?=?3–8 %), and for the modified low temperature, they ranged from 81.5 to 113.8 % (RSD?=?3–10 %).     

Benzo[a]pyrene and total polycyclic aromatic hydrocarbons (PAHs) levels in vegetable oils and fats do not reflect the occurrence of the eight genotoxic PAHs

Concentrations of polycyclic aromatic hydrocarbons (PAHs) were determined in 115 samples of olive oil (extra virgin olive oil, virgin olive oil, olive oil, pomace olive oil and blended olive oil), cooking oil (corn oil, sunflower oil, sesame oil, palm olein oil, soya oil, canola oil, mustard oil, peanut oil and mixed vegetable oil) and fat (butter and table margarine) collected from retail stores in Kuwait. Carcinogenic benzo[a]pyrene (BaP) was detected in 43% of the samples analyzed. Benz[a]anthracene and chrysene were detected in 37 and 45% of the samples, respectively, that did not contain BaP. Of the individual non-carcinogenic PAHs, naphthalene showed the highest mean concentration (14 µg kg^?1), while for the carcinogenic PAHs, BaP (0.92 µg kg^?1) and chrysene (0.87 µg kg^?1) showed the highest mean values. Approximately 20% of the samples within the olive oil and cooking oil sub-categories exceeded the EU maximum tolerable limit for BaP, with the highest level of 6.77 and 11.1 µg kg^?1, respectively. For the fat sub-category, 9% of the samples exceeded the tolerance limit, with the highest level of 3.67 µg kg^?1. The Kuwaiti general population's dietary exposure to the genotoxic PAHs (PAH8: benz[a]anthracene, chrysene, benzo[b]fluoranthene, benzo[k]fluoranthene, benzo[a]pyrene, indeno[1,2,3-cd]pyrene, dibenz[a,h]anthracene and benzo[ghi]perylene) was estimated to be 196 ng day^?1 (3.3 ng kg^?1 bw day^?1, assuming an average adult body weight of 60 kg). Results indicated that PAH8 and BaP_eq (total sum benzo[a]pyrene equivalents) are more reliable measures of the concentrations of other carcinogenic PAHs in oil and fat samples, while BaP and PAHs alone are not good indicators of the occurrence or degree of contamination by carcinogenic PAHs in these food products.     

Determination of Triazole Fungicides in Liquid Samples Using Ultrasound-Assisted Emulsification Microextraction with Solidification of Floating Organic Droplet Followed by High-Performance Liquid Chromatography

An ultrasound-assisted emulsification microextraction with solidification of organic droplet method followed by high-performance liquid chromatography with diode array detection for six triazole fungicide determination (diniconazole, fluquinconazole, flusilazole, myclobutanil, tebuconazole, and tetraconazole) was developed. After some preliminary experiments, undecanol was chosen as extracting solvent using 50 μL for 10 mL of liquid sample. A central composite design was performed to obtain the best experimental conditions for the following variables NaCl concentration (250 g L^?1), extraction time (18 min), and temperature (30 °C) in ultrasonic bath. After the ultrasound-assisted extraction, two steps considering centrifugation (4,200 rpm, 10 min) and solidification (5 min, 3 °C) were done. Following these conditions, the method showed linearity higher than 0.9930 with the concentration ranged from 20 to 890 μg L^?1. The limits of detection obtained using calibration curves were from 10.9 to 17.2 μg L^?1 and the intra- and inter-day repeatability at two levels showed RSD values between 1.9 and 10.6 %. The enrichment factors for the studied triazoles were between 226 (flusilazole) and 255 (tebuconazole). Recovery studies at two spiked levels in apple and grape juices gave values from 64 to 112 %.     

Optimization of Ultrasound-Assisted Extraction of Lycopene from Papaya Processing Waste by Response Surface Methodology

Lycopene possesses strong antioxidant ability, which may provide protection against cancer and other degenerative diseases. An ultrasound-assisted extraction method has been developed for the extraction of lycopene from papaya (Carica papaya L.) processing waste. Optimization conditions were firstly determined using single factor experiment, and then response surface methodology was used. Analysis showed that second-order polynomial models produced a satisfactory fitting of the experimental data with regard to lycopene (R ²?=?0.9147, P?<?0.001). The optimal conditions were 42.28 % ethanol in ethyl acetate as a solvent and extraction for 26.09 min at 50.12 °C. Under these conditions, the maximum yield of lycopene was 189.8?±?4.5 μg/g fresh weight (FW), which was higher than that obtained using the traditional extracting method (153.9?±?7.8 μg/g FW) and the Soxhlet extraction method (68.3?±?4.1 μg/g FW). The crude extract obtained could be used as either food additive or for further isolation and purification of lycopene. The results obtained are helpful for full utilization of papaya.     

A Rapid Direct Solvent Extraction Method for the Extraction of 2-Dodecylcyclobutanone from Irradiated Ground Beef Patties Using Acetonitrile

Abstract: The amount of irradiated beef in the U.S. market is growing, and a reliable, rapid method is needed to detect irradiated beef and quantify the irradiation dose. The official analytical method (BS EN 1785 2003) that has been adopted by the European Union is time consuming. The objective of this study was to develop a rapid method for the analysis of 2-dodecylcyclobutanone (2-DCB) in irradiated beef. A 5 g sample of commercially irradiated ground beef patty (90/10) was extracted with n-hexane using a Soxhlet apparatus or with acetonitrile via direct solvent extraction. The Soxhlet hexane extract was evaporated to dryness, and the sample was dissolved in a mixture of ethyl acetate and acetonitrile (1:1). The defatted extract was purified with a 1 g silica cartridge. Another 5 g aliquot of the same patty was mixed with 50 mL acetonitrile and either blended for 1 min with a hand blender or crushed for 10 min with a glass rod. The extraction procedure was repeated 3 times, and the acetonitrile was collected and evaporated to dryness. Eluants from both methods were concentrated under nitrogen and injected into a gas chromatography-mass spectrometry. The 2-DCB concentration in the commercial samples was 0.031 ± 0.0026 ppm (n = 5) for the Soxhlet method and 0.031 ± 0.0025 ppm (n = 10) for direct solvent extraction. Recovery of 2-DCB from spiked beef samples in the direct solvent extraction method was 93.2 ± 9.0% (n = 7). This study showed that the direct solvent extraction method is simple and as efficient and reproducible as the Soxhlet method.     

Rapid and sensitive method for the determination of four EU marker polycyclic aromatic hydrocarbons in cereal-based foods using isotope-dilution GC/MS

A rapid and sensitive method has been developed for the determination of the four European Union marker polycyclic aromatic hydrocarbons (PAHs; benz[a]anthracene, chrysene, benzo[b]fluoranthene and benzo[a]pyrene) in some cereal-based foods. The method is based on pressurised liquid extraction (PLE), solid-phase extraction clean-up (SPE) and isotope-dilution gas chromatography with mass-spectrometric detection (GC/MS). The developed method was calibrated for the content range of 0.05–12.5 µg kg^?1 (expressed on a product basis). Recoveries of PAH were monitored in each sample via the recovery of ¹³C-labelled PAHs. Recovery values were in the range between 86% and 91%, with relative standard deviations (RSDs) between 5% and 9%. The achieved limits of detection for all analytes were below 0.05 µg kg^?1. The applicability of the method for the analysis of routine samples was studied by the analysis of a set of commercial bread and breakfast cereal samples. In all analysed samples, benzo[a]pyrene (BAP) was the most prevalent PAH with the content between 0.09 and 0.30 µg kg^?1. On average, samples showed low levels of the sum of the four EU marker PAHs (ΣPAH4) that ranged between 0.11 and 0.22 µg kg^?1 for bread samples and between 0.23 and 0.87 µg kg^?1 for breakfast cereal samples. The developed method was found suitable for the determination of PAHs in cereal-based foods like cornflakes and breads with total relative fat contents below 3.5%.