POPs and PAHs in fish oil-based food supplements at the Czech market.

The objectives of this study were to assess concentrations of three groups of persistent organic pollutants (POPs) and polycyclic aromatic hydrocarbons (PAHs) in 44 fish oil-based food supplements, to estimate their daily intake by consumers and, to evaluate the compliance of the oil samples with the oil origin declarations (cod liver oil or fish oil). The concentrations of ∑PCBs (7 congeners), OCPs (19 compounds, represented mainly by ∑DDTs), ∑PBDEs (10 congeners), and ∑PAHs (16 compounds) found in samples ranged between 0.15-55.7 µg kg-1, 0.93-72.8 µg kg-1, 0.28-27.5 µg kg-1, and 0.32-51.9 µg kg-1, respectively. Besides, the authenticity of the oils was assessed based on the fingerprints obtained by DART-HRMS, an ambient mass spectrometry technique. Four samples declared as fish oil were probably prepared from cod liver oil, which is much cheaper. Furthermore, these samples contained elevated concentrations of halogenated POPs when compared to supplements produced from fish oil.

Influence of dough composition on the formation of processing contaminants in yeast-leavened wheat toasted bread.

The influence of dough composition on acrylamide, 3-monochloropropane-1,2-diol (3-MCPD) esters, and glycidyl esters (GE) formation during bread toasting was investigated. The doughs differed in added amounts of soy lecithin, salt, and reducing agents (l-cysteine and glutathione). The toasting of bread for 2.5 min considerably enhanced the formation of acrylamide and 3-MCPD esters. The addition of lecithin (1%, w/w) resulted in four times higher content of 3-MCPD esters in toasted bread slices. No distinct relationship between dough composition and GE formation in untoasted and toasted bread was found. The addition of reducing agents (0.05%, w/w) mitigated during toasting not only the formation of 3-MCPD esters (more than six times) but also the extent of Maillard reaction that resulted in three times lower amounts of acrylamide and predominant formation of alcohol-like compounds. Toasted bread without reducing agents contained typical Maillard reaction compounds such as aldehydes, alkyl pyrazines, and derivatives of furan.

Cranberries versus lingonberries: A challenging authentication of similar Vaccinium fruit.

Due to unique phytochemicals contained, Vaccinum berries are known to have a number of positive health effects. In this context, lingonberries (Vaccinium vitis-idaea) are considered to be the most effective, thus finding many uses. Recently, fraud suspicion on lingonberries-based products has been reported, partial or even total replacement by less valued cranberries (Vaccinium macrocarpon) was found. In this study, metabolomic fingerprinting employing instrumental platform consisting of U-HPLC-HRMS/MS was investigated for discrimination between the two Vaccinum berries species. Methanolic extracts of 33 authentic samples from two harvest years were analyzed and chemometric evaluation was performed to identify significant marker compounds, their stability during drying process was assessed, too. The characteristic markers most contributing to berries classification were representatives of polyphenols and phospholipids. Peonidin 3-O-arabinoside and myricetin 3-O-glucoside, not occurring in lingonberries, enabled to discover the presence of cranberries in prepared admixtures down to 1% (w/w).

Assessment of pesticide residues in strawberries grown under various treatment regimes.

The dynamics of pesticide residues in strawberries that involved quantification of pesticide residues in ripe fruits after model treatment was evaluated in repeated field trials conducted over 3 years. Sixteen commercial pesticide formulations in various combinations were employed in applications from 7 to 44 days before harvest. Altogether 21 active ingredients and some of their metabolites were determined in treated strawberries using LC-MS and GC-MS methods. Except for propargite, the concentrations of all active ingredients declined below the respective MRLs (Regulation (EC) No. 396/2005); nevertheless, most of the tested fungicides often persisted above the 0.01 mg kg⁻¹ limit required by baby food producers to avoid the risk of exceeding the 'baby food limit' established in Commission Directive 2006/141/EC. On the other hand, residues of the majority of tested insecticides, namely spinosad, pymetrozine, deltamethrin, lambda-cyhalothrin and azadirachtin, declined below this limit.

Evaluation of direct analysis in real time ionization-mass spectrometry (DART-MS) in fish metabolomics aimed to assess the response to dietary supplementation.

Ambient mass spectrometry employing a direct analysis in real time (DART) ion source coupled to a medium high-resolution/accurate mass time-of-flight mass spectrometer (TOFMS) was used as a rapid tool for metabolomic fingerprinting to study the effects of supplemental feeding with cereals (triticale) on the composition of muscle metabolites of common carp (Cyprinus carpio L.). First, the sample extraction and DART-TOFMS instrumental conditions were optimized to obtain the broadest possible representation of ionizable compounds occurring in the extracts obtained from common carp muscle. To this end, a simultaneous (all-in-one) extraction procedure was developed employing water and cyclohexane mixture as the extraction solvents. Under these conditions both polar as well as non-polar metabolites were isolated within a single extraction step. Next, the metabolomic fingerprints (mass spectra) of a large set of common carp muscle extracts were acquired. Finally, the experimental data were statistically evaluated using principal component analysis (PCA) and orthogonal partial least squares discriminant analysis (OPLS-DA). Using this approach, differentiation of common carp muscle in response to dietary supplementation (feeding with and without cereals) was feasible. Correct classification was obtained based on the assessment of polar and as well as non-polar extracts fingerprints. The current study showed that DART-TOFMS metabolomic fingerprinting represents a rapid and powerful analytical strategy enabling differentiation of common carp muscles according to feeding history by recording metabolomic fingerprints of ionizable components under the conditions of ambient MS.

Rapid determination of polycyclic aromatic hydrocarbons (PAHs) in tea using two-dimensional gas chromatography coupled with time of flight mass spectrometry.

A simple, fast, and cost effective sample preparation procedure has been developed and validated for the determination of 15+1 European Union Polycyclic Aromatic Hydrocarbons (15+1 EU PAHs) in dried tea leave samples. Based on a critical assessment of several sample extraction/clean-up approaches, the method based on the ethyl acetate extraction followed by the use of PAHs dedicated cartridges with molecularly imprinted polymers (MIPs) has been found as an optimal alternative in terms of time demands and obtained good extract purity. For the final identification/quantification of target PAHs, two dimensional gas chromatography coupled to a time-of-flight mass spectrometry (GC×GC-TOFMS) was used. The performance characteristics of the overall analytical method for individual PAHs determined at three spiking levels (0.5, 2.5 and 5 µg kg(-1)) were in following ranges: limits of quantitation (LOQs) 0.05-0.2 µg kg(-1), repeatabilities 2-9%, and recoveries 73-103%. The recoveries achieved by the newly developed sample preparation procedure when employed for naturally contaminated sample ("incurred" PAHs) were comparable to those obtained by other routinely used approaches employing sonication and/or pressurised liquid extraction for sample analytes isolation. The validated method was subsequently used for the determination of selected genotoxic PAHs in 36 samples of black and green tea obtained from the Czech retail market. The levels of ΣPAH4 (sum of benzo[a]anthracene (BaA), chrysene (CHR), benzo[b]fluoranthene (BbFA) and benzo[a]pyrene (BaP)) in black and green tea leaves ranged from 7.4 to 700 µg kg(-1) and from 4.5 to 102 µg kg(-1), respectively. Contamination of tested tea samples by BaP was in the range of 0.2-152 µg kg(-1).

Safe apples for baby-food production: survey of pesticide treatment regimes leaving minimum residues.

A total of 19 pesticide preparations were used according to agricultural practice in six trials in apple orchards. Using gas chromatography-mass spectrometry (GC-MS) and liquid chromatography-tandem mass spectrometry (LC-MS/MS), premature Golden Delicious apples collected 64, 50, 36 days before harvest and mature fruit were examined for residues of active ingredients. No residues of triflumuron, triazamate, chlorpyrifos, etofenprox, fenoxycarb, kresoxim-methyl, cyprodinyl, difenoconazole or thiram were detected in the first sampling. Also, the levels of chlorpyrifos-methyl, penconazole, tebuconazole and tolylfluanid dropped during the pre-harvest interval. Detectable residues of pyridaben, thiacloprid, trifloxystrobin and tetraconazole in harvested fruits were below 0.01 mg kg(-1), which is the maximum concentration of residues acceptable by baby-food producers in any raw material. The only residues exceeding this concentration were captan and teflubenzuron. Based on the data, farmers can choose pesticides for optimal treatment of plants, while enabling growth of a safe crop suitable for baby-food production.