Acrylamide monitoring in Switzerland, 2007–2009: results and conclusions

Parallel to the European Union acrylamide monitoring for the years 2007–2009, Switzerland performed its own monitoring, covering the whole range of products that significantly contain acrylamide (almost 300 samples per year), but focusing on those products that may result in high exposure. As reducing sugars are critical for potato products, these were included. No significant change, particularly improvement, was noticed, especially regarding those products for which substantial potential for improvement is known. ‘Western-style’ French fries continued to contain some four times more reducing sugars than ‘traditional’ fries, with correspondingly higher acrylamide in the finished product. The supply of raw potatoes low in reducing sugars by retail shops needs improvement, but there seemed to be insufficient willingness on a voluntary basis. A foreign producer was successful in penetrating the Swiss market with special potato chips containing up to 7000 µg kg^?1 acrylamide and only harsh measures could stop this. Three of about 61 products in the group of bakery ware showed a marked improvement. But there was also a store brand cracker that competed with a leading brand which contained 15 times more acrylamide (845 µg kg^?1). Cereals contained 1080 µg kg^?1 acrylamide and even a warning did not prompt the producer to sell substantially better products one year later. It seems that only measures by the authorities will achieve improvements. The following seem promising: a limit for reducing sugars in prefabricates for French fries; the improved supply of raw potatoes low in sugars for roasting and frying; a legal limit for acrylamide content in potato chips; a general provision that products must not contain substantially more acrylamide than achievable by good manufacturing practice; and fryers with a temperature profile from an initial high to a lower final value.     

Modeling oil migration in two-layer chocolate–almond confectionery products

Migration of oil from high oil content fillings into the surrounding chocolate coatings results in product quality changes of filled confections. The objective of this study was to evaluate the mass transfer of liquid oil in two-layer model confectionery samples prepared from four almond products and dark chocolate. Experimental data were acquired using magnetic resonance imaging (MRI). The spatial and temporal experimental data of the liquid oil signal of the almond product and chocolate were modeled using a Fickian diffusion model. Solutions to the diffusion model were derived using both Laplace transform analytical solution and a finite difference numerical solution. For both methods, the boundary condition between the two layers incorporated a partition coefficient. MatLab’s nlinfit routine coupled with the diffusion equation solution provided estimates of the diffusion coefficients, D_a (almond products) and D_c (chocolate), and the partition coefficient. The diffusion coefficient values for the chocolate region ranged between 3 × 10⁻¹¹ m²/s and 6 × 10⁻¹¹ m²/s; the diffusion coefficient values for the almond products were an order of magnitude greater than that of chocolate.     

Pesticide residues determination in China vegetables in 2010–2013 applying gas chromatography with mass spectrometry

The levels of multi-pesticide residues in highly consumed types of vegetables in western regions of China were investigated in this study. Vegetable samples (506) were collected from local markets from 2010 to 2013, and the concentrations of 21 types of organophosphorus (OP) and pyrethroid (PYR) pesticides from the samples were determined by gas chromatography–mass spectrometry (GC–MS). Ten OP pesticides were found in concentrations ranging from 0.0008 to 4.0544 mg/kg. Five types of PYR pesticides were determined to have concentrations in the range of 0.0009 to 6.0827 mg/kg. There were no residues in 69.76% of the samples. A portion (25.49%) of the samples contained pesticide residues less than or equal to the maximum residue limits (MRLs), and 4.94% of samples contained pesticide residues greater than their MRLs. This study provides useful information on the current contamination status of a key agricultural area in China from 2010 to 2013 and highlights the need for regular monitoring of pesticide residues in a greater number of vegetable samples and for longer periods, especially in leafy vegetables, to protect consumers.     

Simultaneous determination of aspartame,acesulfame-K,saccharin, citric acid and sodium benzoate in various food products using HPLC–CAD–UV/DAD

A newly developed method for simultaneous determination of aspartame, acesulfame-K, saccharin, citric acid and sodium benzoate in various diet supplements and non-alcoholic beverages in a single run is presented. The analytes were analysed by high-performance liquid chromatography coupled to a charged aerosol (Corona CAD) and ultraviolet–diode array detectors simultaneously connected in series. Mass spectrometer MicrOTOF-QII from Bruker Daltonik (Bremen, Germany) was used to obtain the mass spectra for peak identifications. The method was validated using a Thermo Hypersil Gold-C18 column packed with 5 μm shell particles (150 × 4.6 mm) and methanol–water with 0.05 % TFA gradient mobile phase at a flow rate of 0.80 mL/min. The elaborated method was validated for linearity, precision and accuracy. The analytical results obtained in the validation study were highly satisfying; the recoveries for the analytes studied ranged between 98.1 and 101 % and the precision values from 0.11 to 1.73 %. By these procedures, the three sweeteners (aspartame, acesulfame-K and saccharin), citric acid and sodium benzoate could be well separated and quantitatively determined in varied food products. Hundred millilitres of soft drinks contained on average 5.50 mg of aspartame, 6.38 mg of saccharin, 8.94 mg of acesulfame-K, 9.05 mg of sodium benzoate and 111 mg of citric acid. Citric acid was the most abundant additive in all the samples analysed except for table sweeteners, and its highest concentration was determined in diet supplements, i.e. 347 mg/g. The percentage of adequate daily intake realisation in case of all additives is lower than 10 %, except for sodium benzoate in isotonic drinks (10.1 %).     

Evaluation of a GC–MS method for benzyl chloride content in processed food,meats, and marine products distributed in Korea

Food Science and Biotechnology - Benzyl chloride is a harmful chemical that contaminates air, water, and food. A static headspace GC–MS method for determining benzyl chloride in food was...     

Ethanol in food: liquid–vapour partition in model systems containing Maillard reaction products

The effect of Maillard reaction products (MRPs) with different browning degree on the liquid–vapour partition of ethanol was studied in model systems. In particular, glucose–glycine aqueous solutions subjected to different heat treatments, which consequentely had different water activity values, were added to increasing amounts of ethanol and analysed for ethanol vapour pressure. In order to study the effects of the water activity change and of melanoidins' formation on the ethanol partition, experiments were also carried out on samples equilibrated at the same water activity. Ethanol vapour pressure decreased as the Maillard reaction proceeded. This result was attributed to the increase in water activity rather than to binding effects of melanoidins towards ethanol. Changes in water activity were mainly due to reagent consumption, water molecule formation and melanoidin production.     

Occurrence and intake of deoxynivalenol in cereal-based products marketed in Korea during 2007–2008

The occurrence of deoxynivalenol (DON) was investigated in 514 cereal-based products (corn-based, n = 125; barley-based, n = 96; wheat-based, n = 94; rice-based, n = 199) marketed in Korea during 2007?2008, and estimates of DON intake were determined. Samples were analysed by high-performance liquid chromatography (HPLC) with ultraviolet light (UV) detection after immunoaffinity clean-up. The limits of detection (LOD) and limits of quantification (LOQ) were 2.2 and 5.6 µg kg^–1, respectively. Recoveries and repeatability expressed as coefficients of variation (CV) were 82.3–100% and 2.4–15.3% in beer, bread and dried corn. The incidences and mean levels of DON were 56% and 68.9 µg kg^?1 for corn-based products, 49% and 24.1 µg kg^?1 for wheat-based products, 43% and 7.5 µg kg^?1 for barley-based products, and 16% and 3.4 µg kg^?1 for rice-based products, respectively. The estimated daily intake of DON from the consumption of rice-based, wheat-based, barley-based and corn-based products were 0.0038 µg kg^?1 bw day^?1, 0.0032 µg kg^?1 bw day^?1, 0.0015 µg kg^?1 bw day^?1 and 0.0002 µg kg^?1 bw day^?1, respectively. These values represent 0.38%, 0.32%, 0.25% and 0.01% of the provisional maximum tolerable daily intake (PMTDI) of 1 µg kg^?1 bw day^?1. These results indicate that rice-based products are major contributors to DON exposure in Korea, even though the current exposure level is unlikely to cause adverse health effects.     

Comparison of headspace-SPME-GC–MS and LC–MS for the detection and quantification of coumarin,vanillin, and ethyl vanillin in vanilla extract products

A headspace-solid phase micro-extraction (HS-SPME) GC–MS method has been developed for the determination of coumarin, vanillin and ethyl vanillin in vanilla products. Limits of detection ranged from 1.33 to 13.2 ng mL⁻¹. Accuracy and precision data for the method were measured and compared to those obtained using LC-ESI-MS. A survey of 24 commercially available vanilla products was completed using both techniques. No coumarin was detected in any of the samples. Examination of the GC–MS chromatograms revealed the presence of 18 other flavor related compounds in the samples. The method validation and sample analysis data using HS-SPME-GC–MS were comparable to those obtained using the LC–MS method. Because the two methods are conceptually different from one another, both methods would not be subject to the same interferences. This would allow them to be used as confirmatory methods for each other.     

Trends in Contact Lens Prescribing in Japan (2003–2016)

Purpose

To review contact lens prescribing trends in Japan between 2003 and 2016.

Determination of Gibberellin A3 residue in fruit samples by liquid chromatography–tandem mass spectrometry

A fast, simple, low cost, and high throughput method has been developed for the determination of Gibberellin A3 residue in fruit samples (apple, orange, peach, pear and grape). Analysis is performed by LC–MS/MS operated in the multiple reaction monitoring (MRM) mode, acquiring two specific precursor-product ion transitions per target compound. The method has been validated showing good linearity and selectivity. Limits of quantification (LOQs) were 10 μg kg⁻¹ for apple, orange, peach, pear and grape samples. The average recoveries, measured at three concentration levels (10, 20 and 200 μg kg⁻¹) were in the range 77.8–96.2% for the compound tested with relative standard deviations below 13.7%. The proposed method is rapid, simple and could be utilised for the routine analysis of Gibberellin A3 in fruit samples.     

Multi-residual Pesticide Monitoring in Commercial Chinese Herbal Medicines by Gas Chromatography–Triple Quadrupole Tandem Mass Spectrometry

To investigate multi-residual pesticide monitoring data in commercial Chinese herbal medicines on major markets, an easy, rapid, and selective gas chromatography with mass spectrometry (GC/MS/MS) method was established for simultaneously determining multi-residual pesticides including organochlorine, pyrethroid, carbamate, and organophosphorus pesticides in Chinese herbal medicines. The analytical method was based on an efficient extraction procedure and further cleanup steps by solid-phase extraction columns, yielding recovery rates in the range of 70.0–120.0 % for the majority of pesticides, except for hexachlorobenze, diazinon, β-HCH, δ-HCH, and omethoate, with precision values expressed as relative standard deviation of 0.1–14.7 %. The limits of detection of the established GC/MS/MS method for all investigated pesticides ranged from 0.01 to 3.6 μg kg^?1 and limits of quantification from 0.03 to 11.88 μg kg^?1. With this validated method, multi-residual pesticides of 132 Chinese herbal medicine samples were analyzed. The monitoring results indicated that pesticide residue was found in 74 samples. In total, 51 pesticides were found with detection rate ranging from 0.76 to 18.94 %. An 82.3 % of positive pesticides were found in less than 6 % of samples. Hexachlorobenzene was found in 25 samples, quintozene in 15 samples, and acephate and simazine in 13 samples. Concentrations of pesticide residue from monitoring data obtained ranged from 0.5 to 203.5 μg kg^?1. The simple and rapid method can be used as routine analysis method in multi-residual pesticide monitoring of Chinese herbal medicines.     

Determination of Pesticide Residues in Whole Wheat Flour Using Modified QuEChERS and LC–MS/MS

Pesticides in food are a major issue due to their intensive use in agriculture. Thus, an appropriate control of their residues in food samples should be done. In this study, a multiresidue method for the quantification of 37 pesticides in whole wheat flour was developed and validated. The modified QuEChERS (without cleanup) procedure followed by ultra-high performance liquid chromatography coupled to tandem mass spectrometry (UHPLC–MS/MS) was used for analysis. The method was validated according to the European Union SANCO/12,571/ 2013 guidelines and Brazilian Manual of Analytical Quality Assurance. The following parameters were evaluated on the method validation: linearity, limit of detention, limit of quantification, matrix effect, precision, accuracy evaluating the percentage of recovery at three different spike levels, and robustness. Acceptable values were obtained. The linear range used was 1–200 μg kg^?1, resulting to r ² of >0.99. The recovery was satisfactory with 70 and 120 % and RSD of <20 % for most compounds. Assessing the samples collected in the south Brazil region, some pesticide residues were detected in whole wheat flour (carbendazim, chlorpyrifos, deltamethrin, imidacloprid, malathion, pendimethalin, pirimiphos-methyl, triamedifom, and triadimenol). The applicability of this analytical approach was confirmed by successful determination of pesticides in whole wheat flour, a complex matrix.

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Pesticide determination in tomatoes by solid–liquid extraction with purification at low temperature and gas chromatography

In this work, a simple and low cost method, based on solid–liquid extraction with low temperature purification (SLE–LTP), was optimized and validated for the determination of chlorpyrifos, λ-cyhalothrin, cypermethrin and deltamethrin in tomato samples. The analyses were performed by the GC–ECD and confirmed by the GC–MS. The method requires 4 g of tomato and an extraction mixture (8.0 mL acetonitrile, 0.5 mL water and 1.5 mL ethyl acetate), which was established by mixture experimental design. After optimization, pesticide recovery rates ranged from 79% to 97%, with a standard deviation of less than 5%. The SLE–LTP analytical characteristics were compared very favorably to the matrix solid phase dispersion technique, which used ethyl acetate and Florisil for extraction.     

Correlation of rainfall and levels of deoxynivalenol in wheat from Uruguay, 1997–2003

A total of 286 wheat samples for human consumption collected during 1997–2003 from four wheat-producing localities of south-western Uruguay were screened for deoxynivalenol (DON). Quantification was carried on by an immunochemical method using immunoaffinity columns and fluorimetric detection. The incidence of DON was high during the whole survey (58.5–100%), except in 1998 and 1999 in which no contamination occurred. During 2001 and 2002, 100% of samples contained detectable levels of DON, being the mean DON contents 6593 and 5880 µg kg^?1, respectively. The annual maximum levels ranged from 8800 to 11,400 µg kg^?1. A positive correlation between DON levels and precipitation was seen. The 70% of wheat samples destined for human consumption were contaminated with DON. To avoid the introduction of contaminated materials into the food chain process, the adoption of regular screening of the DON level in wheat is recommended, particularly in years with heavy rainfall during the flowering-to-early stages of grain maturity months.     

Survey of sulfites in wine and various Turkish food and food products intended for export, 2007–2010

Surveys were carried out between 2007 and 2010 to determine the total levels of sulfites in 1245 samples of wines, dried apricots, dried vegetables, nuts, juices and purees, frozen foods and cereals containing dried fruit supplied by food inspectors and by food producers for testing or for export certification. Sulfite analysis of wine was carried out using the Ripper method with an LOQ of 5?mg?l^?1 and for dried and other foods the Monier-Williams distillation procedure was employed with an LOQ of 10?mg?kg^?1. In the survey all wines contained measurable sulfites, but with the exception of one sample of white wine they were otherwise below Turkish Food Codex limits of 160?mg?kg^?1 for red wine, 210?mg?kg^?1 to white wine and 235?mg?kg^?1 for sparkling wine. None of the cereal products, frozen foods, juices or purees contained sulfites above 10?mg?kg^?1. However, all dried apricot samples contained significant levels of sulfite with around 40% having levels exceeding the Turkish limit of 2000?mg?kg^?1. Significant levels of sulfite were found in other samples of dried fruit with even a fruit and nut bar containing 1395?mg?kg^?1 of sulfite, suggesting the dried fruit ingredients contained levels above regulatory limits.     

NO2 emissions from agricultural burning in São Paulo, Brazil

We report here on the application of a compact ultraviolet spectrometer to measurement of NO2 emissions from sugar cane field burns in S?o Paulo, Brazil. The time-resolved NO2 emission from a 10 ha plot peaked at about 240 g (NO2) s(-1), and amounted to a total yield of approximately 50 kg of N, or about 0.5 g (N) m(-2). Emission of N as NOx (i.e., NO + NO2) was estimated at 2.5 g (N) m(-2), equivalent to 30% of applied fertilizer nitrogen. The corresponding annual emission of NOx nitrogen from S?o Paulo State sugar cane burning was >45 Gg N. In contrast to mechanized harvesting, which does not require prior burning of the crop, manual harvesting with burning acts to recycle nitrogen into surface soils and ecosystems.     

Tropane and ergot alkaloids in grain-based products for infants and young children in the Netherlands in 2011–2014

An LC-MS/MS multi-method was developed to simultaneously quantify ergot alkaloids (EAs) and tropane alkaloids (TAs) in 113 cereal-based food for infants and young children. To assess yearly variation, samples were collected in 2011, 2012 and 2014. EAs were detected in 54% and TAs in 22% of the samples. Mean EA levels in the three sampling years were 10.6, 6.2 and 8.6 µg kg^?1, respectively (maximum: 115.4 µg kg^?1), indicating that exposure to EAs would not have exceeded the health-based guidance values set by EFSA in 2012. Mean TA levels were 3.9, 2.4 and 0.4 µg kg^?1, respectively (maximum: 80.8 µg kg^?1). The acute reference dose for TAs, derived by EFSA in 2013, would have been exceeded by young children when consuming some of the products sampled in 2011–2012. TA levels had decreased drastically in 2014, possibly due to measures taken by producers as response to the EFSA Opinion.