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Food additives contaminants [journal]
- Furanic compounds and furfural in different coffee products by headspace liquid-phase microextraction followed by gas chromatography-mass spectrometry: survey and effect of brewing procedures. [JOURNAL ARTICLE]
- Food Addit Contam Part B Surveill 2014 Oct 30.
Abstract In this study the levels of furan, 2-methylfuran, 2,5-dimethylfuran, vinyl furan, 2-methoxymethyl-furan and furfural in different coffee products were evaluated. Simultaneous determination of these 6 furanic compounds was performed by a head space liquid-phase micro extraction (HS-LPME) method. A total of 67 coffee powder samples were analyzed. The effects of boiling and espresso making procedures on the levels of furanic compounds were investigated. The results showed that different types of coffee samples contained different concentrations of furanic compounds, due to the various processing conditions such as temperature, degree of roasting and fineness of grind. Among the different coffee samples, the highest level of furan (6320 µg kg(-1)) was detected in ground coffee, while coffee-mix samples showed the lowest furan concentration (10 µg kg(-1)). Levels in brewed coffees indicated that, except for furfural, brewing by an espresso machine caused significant loss of furanic compounds.
- Instability of an aromatic amine in fatty food and fatty food simulant: characterization of reaction products and prediction of their toxicity. [JOURNAL ARTICLE]
- Food Addit Contam Part A Chem Anal Control Expo Risk Assess 2014 Oct 29.
It is a well known fact that amines are not stable in food of fatty nature. In this study the synthesis and characterization of the products obtained as a result of the reaction of amines in a fatty medium is reported. Based on the well known reactions among amines and acid and esters groups, two novel compounds have been synthesized using m-xylylenediamine (mXDA), a primary diamine widely used as monomer in the manufacture of food contact materials and two fatty acids, oleic acid and palmitic acid, which occur in most of fats. The resulting compounds were two molecules belonging to the family of fatty acid amides, dioleamide and dipalmitamide. A complete characterization of both products were carried out employing several techniques such as infrared spectroscopy, (1)H and (13)C NMR spectroscopy, electron ionisation (EI) mass spectrometry, LC-MS/MS and UV spectrometry. The results obtained by the different techniques were well correlated. In the second part of the work, the formation of these compounds in real samples was evaluated. For this purpose a certain volume of olive oil was spiked with a known amount of mXDA. Olive oil was selected as a fatty medium since it is a widely-consumed food and additionally it is used as a fatty food simulant in migration studies of food contact materials. A method was developed to extract the fatty acid amides from the fatty matrix, which were then identified by LC-MS/MS. The toxicity of the synthesized compounds was predicted using a toxicity estimation software tool.
- Quantitation of multiple mycotoxins and cyanogenic glucosides in cassava samples from Tanzania and Rwanda by an LC-MS/MS based multi-toxin method. [JOURNAL ARTICLE]
- Food Addit Contam Part A Chem Anal Control Expo Risk Assess 2014 Oct 28.
A multi-mycotoxin method based on liquid chromatography/tandem mass spectrometry (LC-MS/MS) was used for a mycotoxin survey in 627 samples of processed cassava collected from different districts across Tanzania and Rwanda after the method performance for this matrix had been determined. Matrix effects as well as extraction efficiencies were found to be similar to most other previously investigated matrices with the exception of distinct matrix effects in the negative ionization mode for early eluting compounds. Limits of detection were far below the regulatory limits set in the EU for other types of commodities. Relative standard deviations were generally lower than 10% as determined by replicates spiked on two concentration levels. The sample-to-sample variation of the apparent recoveries was determined for 15 individually spiked samples during three different analytical sequences. The related standard deviation was found to be lower than 15% for most of the investigated compounds, thus confirming the applicability of the method for quantitative analysis. The occurrence of regulated mycotoxins was lower than 10% (with the exception of zearalenone) and the related limits were exceeded only in few samples, which suggests that cassava is a comparatively safe commodity as regards mycotoxins. The most prevalent fungal metabolites were emodin, kojic acid, beauvericin, tryptophol, 3-nitropropionic acid, equisetin, alternariol methylether, monocerin, brevianamide F, tenuazonic acid, zearalenone, chrysophanol, monilifomin, enniatins, apicidin and macrosporin. The related concentrations exceeded 1 mg/kg only in few cases. However, extremely high levels of cyanogenic plant toxins, which had been previously added to the method, were observed in few samples, pointing out the need for improved post-harvest management to decrease the levels of these compounds.
- Foreign matter contaminating ethanolic extract of propolis: a filth-test survey comparing products from small beekeeping farms and industrial producers. [JOURNAL ARTICLE]
- Food Addit Contam Part A Chem Anal Control Expo Risk Assess 2014 Oct 27.
Propolis is a resinous material collected by honeybees from exudates and buds of the plants. It has been widely used as a remedy by humans since ancient times, as well as for dietary supplements and cosmetics. European legislation recently focused on quality and hygiene standards of foods, including beehive products, and extensive efforts have been done to avoid the presence of chemical contaminants, whilst in contrast few studies have investigated the magnitude of contamination by physical ones. We conducted a filth-test survey to evaluate the contamination of ethanolic extract of propolis by foreign materials. We also compared the abundance of contaminants in propolis extracts currently marketed by small beekeepers and industrial producers. We found different foreign materials in the ethanol extract of propolis. Contaminants differed in abundance, with a higher number of carbon particles [small beekeepers: 2.70 ± 0.63; industrial producers: 1.25 ± 0.49; mean (n/30 mL) ± SE] and other inorganic fragments (small beekeepers: 3.50 ± 0.31; industrial producers: 3.88 ± 1.11) than arthropod fragments (small beekeepers: 0.30 ± 0.21; industrial producers: 0.38 ± 0.26) and mammal hairs (small beekeepers: 0.10 ± 0.10; industrial producers: 0.38 ± 0.26). No differences in the abundance of foreign matter between propolis from small beekeepers and industrial producers were found, allowing us to point out an increased awareness by small producers of issues inherent in hygiene management. Contamination of propolis extracts by animal body parts, such as insect fragments, mites and rodent hairs indicates poor management of hygiene in the production process and low effectiveness of the filtration phase. Animal-borne contaminants can act as pathogen vectors as well as dangerous allergens when ingested or applied to human skin. The filth-test applied to ethanolic propolis extract quality control can be considered a promising tool, also for small beekeeper activities, since it is cheap and allows quick interpretation of results.
- Growing patterns to produce "nitrate-free" lettuce (Lactuca sativa). [JOURNAL ARTICLE]
- Food Addit Contam Part A Chem Anal Control Expo Risk Assess 2014 Oct 27.
Vegetables may contain significant amounts of nitrate and, therefore, may pose health hazards to consumers by exceeding the accepted daily intake for nitrate. Different hydroponic growing patterns were examined in this work in order to obtain "nitrate free lettuces". Growing lettuces on low nitrate content nutrient solution resulted in a significant decrease in lettuces' nitrate concentrations (1741 versus 39 mg kg(-1)), however, the beneficial effect was cancelled out by an increase in the ambient temperature. Nitrate replacement with ammonium was associated with an important decrease of the lettuces' nitrate concentration (from 1896 to 14 mg kg(-1)) and survival rate. An economically feasible method to reduce nitrate concentrations was the removal of all inorganic nitrogen from the nutrient solution before the exponential growth phase. This method led to lettuces almost devoid of nitrate (10 mg kg(-1)). The dried mass and calcinated mass of lettuces, used as markers of lettuce's quality, were not influenced by this treatment, but a small reduction (18%, p <0.05) in the fresh mass was recorded. The concentrations of nitrite in the lettuces and their modifications are also discussed in the paper. It is possible to obtain "nitrate-free" lettuces in an economically feasible way.
- Ochratoxin A in Chinese dried jujube: method development and survey. [JOURNAL ARTICLE]
- Food Addit Contam Part A Chem Anal Control Expo Risk Assess 2014 Oct 27.
A method was developed for the determination of the mycotoxin ochratoxin A in dried jujube (Zizyphus jujuba Miller) using alkaline methanolic extraction, immunoaffinity column clean-up (IAC) and liquid chromatography-tandem mass spectrometry (LC-MS/MS) determination. The limit of detection (LOD) was 0.01 μg/kg and limit of quantification (LOQ) was 0.03 μg/kg. The average recoveries were 82%, 98% and 115% at 5, 0.5 and 0.1 μg/kg spiked levels with relative standard deviation (RSD) of 2.9%, 5.2% and 9.2% accordingly. The method showed good linearity for both solvent standard calibration and matrix-matched standard calibration with correlation coefficients of 0.9998 and 0.9997 respectively. The intra-day precision RSD was 3.3% and the inter-day precision RSD was 4.0%. In addition, there was almost no matrix interference in LC-MS/MS detection after the IAC clean-up process. The proposed analytical set-up was successfully used to test 20 samples that were collected from local markets and stores. The results showed that all of the samples were positive and the amount of OTA ranged from <0.01 to 0.18 μg/kg, with a mean level of 0.14 μg/kg. In spite of the high positive rate, samples with this level would not cause significant health effects after consumption.
- Validation of a lateral flow test (MRLAFMQ) for detection of aflatoxin M1 at 50 ng l(-1) in raw commingled milk. [JOURNAL ARTICLE]
- Food Addit Contam Part A Chem Anal Control Expo Risk Assess 2014 Oct 24.
Aflatoxin M1 contamination in dairy products is a risk when feedstuff contaminated with aflatoxin B1 produced by molds is consumed by milk-producing animals. Milk can be screened for aflatoxin M1 at the EU maximum limit (ML) of 50 ng l(-1) by a lateral flow test, the MRLAFMQ (Aflatoxin M1) Test. The method takes 15 min with no milk dilution or a sample preparation step. The lateral flow assay was validated at ILVO-T&V according to EU guidelines using fortified raw milk samples. A detection capability of 50 ng l(-1) was demonstrated with a false negative rate lower than 2% at 50 ng l(-1) and a false positive rate of less than 0.3%. Quantitative readings had a mean bias of +2 to 6 ng l(-1) at 50 ng l(-1) with a standard deviation of 5 to 8 ng l(-1). Based on the validation results the test could be considered appropriate for milk screening prior to milk unload at dairies.
- Moisture content and its impact on aflatoxin levels in ready-to-use red chillies. [JOURNAL ARTICLE]
- Food Addit Contam Part B Surveill 2014 Oct 23.
Abstract Moisture content and aflatoxin contamination were analyzed with respect to determine Red Chilli quality. A wide range (9.1-19.8%) of moisture content (MC) with a mean value of 11.4±2.4% was found. Of 116 chilli samples, about 37% had low MC (<10%), 29.4% had medium-low MC (10-12%), 18.9% had medium-high MC (12<MC<14%) and 14.7% were above 14%. These 4 chilli groups had average aflatoxin levels of 2.1±1.1, 5.3±4.2, 8.9±5.9 and 37±20 µg/Kg, respectively. A direct relationship between moisture and aflatoxin content was found. The data best fitted a polynomial trend (R(2)=0.89). The obtained equation could be utilized to assess aflatoxin levels based on moisture content. This study highlights the importance of using properly dried chillies with low MC, i.e. ≤10%, to minimize health hazards associated with aflatoxin contamination.
- The role of choline and glycine betaine in the formation of N,N-dimethylpiperidinium (mepiquat) under Maillard reaction conditions. [JOURNAL ARTICLE]
- Food Addit Contam Part A Chem Anal Control Expo Risk Assess 2014 Oct 21.
This study is the first to examine the role of choline and glycine betaine, naturally present in some foods in particular in cereal grains, to generate N,N-dimethylpiperidinium (mepiquat) under Maillard conditions via transmethylation reactions involving the nucleophile piperidine. The formation of mepiquat and its intermediates piperidine - formed by cyclization of free lysine in the presence of reducing sugars - and N-methylpiperidine were monitored over time (240°C, up to 180 min) using high resolution mass spectrometry in a model system comprised of a ternary mixture of lysine/fructose/alkylating agent (choline or betaine). The reaction yield was compared to data recently determined for trigonelline, a known methylation agent present naturally in coffee beans. The role of choline and glycine betaine in nucleophilic displacement reactions was further supported by experiments carried out with stable isotope-labeled precursors ((13)C- and deuterium-labeled). The results unequivocally demonstrated that the piperidine ring of mepiquat originates from the carbon chain of lysine, and that either choline or glycine betaine furnishes the N-methyl groups. The kinetics of formation of the corresponding demethylated products of both choline and glycine betaine, N,N-demethyl-2-aminoethanol and N,N-dimethylglycine, respectively, were also determined using high resolution mass spectrometry.
- Household dietary exposure to aflatoxins from maize and maize products in Kenya. [JOURNAL ARTICLE]
- Food Addit Contam Part A Chem Anal Control Expo Risk Assess 2014 Oct 17.
Aflatoxicosis has repeatedly affected Kenyans, particularly in the eastern region, due to consumption of contaminated maize. However, save for the cases of acute toxicity, the levels of sub-lethal exposure have not been adequately assessed. It is believed that this type of exposure does exist even during the seasons when acute toxicity does not occur. This study, therefore, was designed to assess the exposure of households to aflatoxins through consumption of maize and maize products. Twenty samples each of maize kernels, muthokoi and maize meal were randomly sampled from households in Kibwezi District of Makueni County in Eastern Kenya and analyzed for aflatoxin contamination. The samples were quantitatively analyzed for aflatoxin contamination using HPLC. The uncertainty and variability in dietary exposure was quantitatively modeled in Ms Excel using Monte Carlo simulation in @Risk software. Aflatoxins were found in 45% of maize kernels at between 18-480 μg/kg, 20% of muthokoi at between 12-123 μg/kg and 35% of maize meal at between 6-30 μg/kg. The mean dietary exposure to aflatoxin in maize kernels was 292 ± 1567 ng kg(-1) body weight day(-1), while the mean dietary exposure to aflatoxin in maize meal and muthokoi were 59 ± 62 ng kg(-1) body weight day (-1) and 27 ± 154 ng kg(-1) body weight day(-1) respectively. The results showed that the amount and frequency of consumption of the three foods is the more important contributing factor than the mean aflatoxin concentration levels, to the risk of dietary exposure to aflatoxins.