Food additives contaminants [journal]
- Optimisation and validation of a new analytical method for the determination of four natural and synthetic hormones using LC-ESI-MS/MS. [JOURNAL ARTICLE]
- Food Addit Contam Part A Chem Anal Control Expo Risk Assess 2016 Aug 30.
A rapid liquid chromatographic-tandem mass spectrometric method was developed for the simultaneous determination of four natural and synthetic hormone residues (progesterone, testosterone, trenbolone acetate and zeranol) in animal tissue samples. Sample preparation was optimised to minimise time and solvent consumption. Meat samples were mechanically homogenised and digested in a procedure that gave similar recoveries to those enzymatically hydrolysed by Helix pomatia. Efficient extraction was achieved using acidified acetonitrile (1% acetic acid). Chromatographic conditions were optimised to minimise matrix effects. Analytes were separated using a C18 column with gradient elution using ammonium formate solution in methanol/water (1:9) and methanol mobile phases. Finally, residues were qualitatively and quantitatively determined by electrospray ionisation tandem mass spectrometry in multiple reaction monitoring mode. LC-MS/MS different parameters (e.g., declustering potential and collision energy) were optimised using API 6500QT; all analytes were measured using positive mode electrospray ionisation (ESI(+ve)) except zeranol which was measured in negative mode (ESI(-ve)). Due to LC-MS/MS signal enhancement/suppression, determination of hormones was based on matrix-matched standard calculations. The method has been validated for the four hormones on meat samples at different fortification levels and showed accepted performance criteria according to the European Commission 2002/657/EC. Decision limits and detection capabilities were estimated for all analytes.
- Level of Natural Hepatotoxin (Indospicine) Contamination in Australian Camel Meat. [JOURNAL ARTICLE]
- Food Addit Contam Part A Chem Anal Control Expo Risk Assess 2016 Aug 30.
Camel meat production for human consumption and pet food manufacture accounts for a relatively small part of overall red meat production in Australia. Reliable statistical data for the Australian production and consumption of camel meat is not available; however, it is estimated that 300,000 feral camels roam within the desert of central Australia, with an annual usage of more than 3000 camels for human consumption, 2000 for pet food manufacture and a smaller number for live export. Despite a small Australian camel meat production, the usage of camel meat for pet food has been restricted in recent years due to reports of serious liver disease and death in dogs consuming camel meat. This camel meat was found to contain residues of indospicine, a non-proteinogenic amino acid found in certain Indigofera spp., and associated with mild to severe liver disease in diverse animals after dietary exposure to this hepatotoxin. The extent of indospicine-contaminated Australian camel meat was previously unknown, and this study sought to ascertain the prevalence of such residue in Australian camel meat. In this study, indospicine levels in ex situ (95 samples collected from an abattoir in Queensland) and in situ (197 samples collected from camels after field culling in central Australia) camel meat samples were quantitated using a validated ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). The quantitation results showed 46.7% of the in situ and 20.0% of the ex situ collected camel meat samples were contaminated by indospicine (> limit of detection (LOD) of 0.05 mg/kg FW). The overall indospicine concentration was higher (p < 0.05) in the in situ collected samples. Indospicine levels detected in the present study are considered to be low; however, a degree of caution must still be exercised, since the tolerable daily intake (TDI) for indospicine is currently not available for risk estimation.
- Fusarium and mycotoxin spectra in Swiss barley are affected by various cropping techniques. [JOURNAL ARTICLE]
- Food Addit Contam Part A Chem Anal Control Expo Risk Assess 2016 Aug 5.
Fusarium head blight is one of the most important cereal diseases worldwide. Cereals differ in terms of the main occurring Fusarium species and the infection is influenced by various factors, such as weather and cropping measures. Little is known about Fusarium species in barley in Switzerland, hence, harvest samples from growers have been collected in 2013 and 2014, along with information on respective cropping factors. The incidence of different Fusarium species was obtained by using a seed health test and mycotoxins were quantified by LC-MS/MS. With these techniques, the most dominant species, F. graminearum, and the most prominent mycotoxin, deoxynivalenol, were identified. Between the three main Swiss cropping systems, "Organic", "Extenso" and "Proof of ecological performance", we observed differences with the lowest incidence and toxin accumulation in organically cultivated barley. Hence, we hypothesise that this finding was based on an array of growing techniques within a given cropping system. We observed that barley samples from fields with maize as previous crop had a substantially higher F. graminearum incidence and elevated deoxynivalenol accumulation compared with other previous crops. Furthermore, the use of reduced tillage led to a higher disease incidence and toxin content compared with samples from ploughed fields. Further factors increasing Fusarium infection were high nitrogen fertilisation as well as the application of fungicides and growth regulators. Results from the current study can be used to develop optimised cropping systems that reduce the risks of mycotoxin contamination.
- Contents of Ag and other metals in food contact plastics with nanosilver or Ag ion and their migration into food-simulants. [JOURNAL ARTICLE]
- Food Addit Contam Part A Chem Anal Control Expo Risk Assess 2016 Aug 3.
Six nanosilver labeled products and 5 silver ion (Ag(+)) labeled products were investigated to measure the migration of Ag from food contact plastics including nanosilver into various food-simulants. The products were obtained in Japanese markets in 2012. Zinc (Zn), another major antimicrobial agent, and three harmful metals, cadmium (Cd), lead (Pb) and arsenic (As), were also examined. Ag and Zn were detected in all 6 nanosilver products at concentration values of 21-200 mg kg(-1) and 8.4-140 mg kg(-1), respectively. These metals were also detected in all 5 Ag(+) products at the same level as nanosilver products. Cd, Pb and As were not detected in any of the samples. Migrations of Ag and Zn were highest into 4% acetic acid, but also observed into water and 20% ethanol. Big differences were not observed in the migration ratio between nanosilver products and Ag(+) products. The ultra-filtration experiments suggested that Ag which migrated from nanosilver products into 4% acetic acid was in ionic form, while that into water and 20% ethanol was in nanoparticle form.
- Survey of undeclared soy allergen levels in the most frequently recalled food categories with or without precautionary labelling. [Journal Article]
- Food Addit Contam Part A Chem Anal Control Expo Risk Assess 2016 Aug; 33(8):1274-82.
A comprehensive study was designed to determine the frequency and levels of soy allergen in packaged bakery and snack food products. A representative sample of products with no soy allergen disclosed on the label was analysed using two widely used enzyme-linked immunosorbent assay (ELISA) methods. Samples were chosen that either had no soy identified on the product label or which had a soy precautionary statement. Among 558 bakery and snack products, soy protein was detected in 17% of the products using the Neogen (NE) kit and 11% of the products using the Elisa Systems (ES) kit. The disagreement rates between kits were 8.8% for bakery products and 3.3% for snack products. Overall soy protein was detected at higher frequency in bakery products than in snack foods. Among 284 bakery samples, soy protein was detected in 25% of the samples with no precautionary statement and 19% of the samples which had a precautionary statement. Among 274 snack samples, soy protein was detected in 11% of the samples with no precautionary statement and 9% of the samples which had a precautionary statement. The sample repeatability was at an acceptable level (< 9%) for each method and food commodity. The reproducibility between kits was 23% for bakery foods and 36% for snack foods. None of the bakery (21) and snack (6) products without precautionary labelling (measured level > 5 ppm) had a higher level of soy protein per serving compared with the eliciting dose10 (ED10) of 10.6 mg for soy allergic patients. But the level of soy protein per serving may be clinically relevant to a subpopulation of soy allergic patients if a more stringent eliciting dose is applied. These findings emphasise that suitable detection methodologies and references doses are crucial for labelling accuracy and the safety of soy allergic consumers.
- Effect of dietary acids on the formation of aflatoxin B2a as a means to detoxify aflatoxin B1. [JOURNAL ARTICLE]
- Food Addit Contam Part A Chem Anal Control Expo Risk Assess 2016 Jul 28.
Aflatoxin B1 (AFB1) is a class 1 carcinogen and a common food contaminant worldwide with widely uncontrolled human exposure. The ability of organic acids to transform AFB1 into a known detoxified form, aflatoxin B2a, was investigated using high performance liquid chromatography-electrospray ionization-time of flight mass spectrometry (HPLC/ESI/TOFMS). The identity of the transformation product was confirmed by accurate mass measurement, chromatographic separation from other aflatoxins, H(1) nuclear magnetic resonance (NMR), and infrared (IR) spectroscopy. Of the weak acids tested, citric acid was found to be the most effective for AFB2a formation. At room temperature, 1 M citric acid was able to convert >97% of AFB1 to AFB2a over 96 hours of treatment. Up to 98% transformation was achieved by boiling AFB1 in the presence of citric acid for 20 minutes. AFB1 hydration after ingestion was explored by spiking AFB1 into simulated gastric fluid containing citric acid. Under these conditions over 71% of AFB1 was hydrated to AFB2a and did not show any reversion to the parent compound after being transferred to a neutral solution. These results provide a basis for a practical and effective method for detoxification of AFB1 in contaminated foods.
- Deoxynivalenol, zearalenone and T-2 in grain based swine feed in Hungary. [JOURNAL ARTICLE]
- Food Addit Contam Part B Surveill 2016 Jul 27.:1-6.
Fusarium genera can produce trichothecenes like deoxynivalenol (DON), zearalenone (ZEN) and T-2 toxin, which can occur in feed cereal grains. Enzyme-linked immunosorbent assays (ELISA) tests of different Hungarian swine feedstuff proved that these mycotoxins were present. In this survey, 45 feed samples from 3 significant Hungarian swine feedstuff manufacturers were tested. ELISA methodology validation showed mean recovery rates in ranges from 85.3% to 98.1%, with intermediate precision of 86.9-96.9% and variation coefficients of 3.4-5.7% and 5.9-7.1%, respectively. The results showed that among Fusarium toxins, generally DON was present in the highest concentration, followed by T-2 and finally ZEN in all tested swine feeds. Each of the mycotoxins was found above the limit of detection in all swine feedstuffs. Boars feed's DON (average ± standard deviation was 872 ± 139 µg kg(-1)) and ZEN (172 ± 18 µg kg(-1)) results of one of the manufacturers were above the guidance values. It indicates the necessity for efficient monitoring of DON, ZEN and T-2 mycotoxins in swine feeds.
- Mitigation of the processing contaminant acrylamide in bread by reducing asparagine in the bread dough. [JOURNAL ARTICLE]
- Food Addit Contam Part A Chem Anal Control Expo Risk Assess 2016 Jul 27.
Over the past few years there has been an increasing awareness regarding acrylamide (AAM) content of various foods. Although there are several relevant articles on acrylamide mitigation in industrially prepared products, the literature regarding homemade preparations is rather scarce. The objective of this study was to mitigate the acrylamide formation in baked buns made with 1:1 sifted wheat/wholegrain flour through the depletion of asparagine (ASN) in the bread dough. Using a full factorial design the effect of four factors (yeast amount, fermentation time, fermentation temperature and yeast types) was tested. Liquid chromatography-tandem mass spectrometry (LC-MS/MS) was used for acrylamide and its main precursor, asparagine determination. The resulting asparagine depletion in the dough (68-89%) is significantly affected by fermentation time and yeast type, while acrylamide mitigation levels in the baked buns are significantly influenced by yeast amount, fermentation time, and yeast type. The mean concentrations for each combination range between 5-15 µg kg(-1).
- Effects of different drying treatments on fungal population and ochratoxin A occurrence in sultana type grapes. [JOURNAL ARTICLE]
- Food Addit Contam Part A Chem Anal Control Expo Risk Assess 2016 Jul 27.
This study aimed to determine the changes in mould and ochratoxin A (OTA) occurrence in sultanas under three different conventional drying conditions. Five different vineyards were chosen, and the three different treatments were applied to these grapes while drying. At the end of the drying process, total mould and black aspergilli (BA) populations in the samples varied from 2.45 to 5.61 log colony-forming units (CFU) g(-1) and from 0 to 4.92 log CFU g(-)1, respectively. Significant increases (p<0.05) occurred in mould loads depending on the extending drying period. However, independent of vineyard location, all of the samples treated with cold dipping solution showed the lowest fungal loads. These results indicate that dipping solution treatment was the most effective drying method to minimize fungal infection of grapes. The expected results could not be achieved by drying grapes artificially contaminated with ochratoxigenic Aspergillus carbonarius spores. Seventy-one of 96 isolates (73.95%) obtained during drying were Aspergillus spp., and the remaining (n=25, 26.05%) belonged to other genera, such as Penicillium, Trichoderma and Cladosporium. Grape juice-based agar medium was used to determine the realistic OTA production capacities of the isolated mould strains. The highest OTA production capacities were 809.70±9.19, 87.58±16.89 and 45.44±18.78 ng/g in 50% grape juice agar (GJ50), all 5 of which were from A. niger isolates. OTA was not present in any sample during the drying period; however, OTA was detected in two samples at 0.32±0.15 and 0.52±0.36 µg kg(-)1 after the end of the drying process. The Limit of Detection (LOD) and Limit of Quantitation (LOQ) of the method used for detecting OTA in samples were 0.1 and 0.3 µg kg(-)1, respectively.
- Nitrofurazone quantification in milk at the European Union minimum required performance limit of 1 ng g(-1): circumventing the semicarbazide problem. [Journal Article]
- Food Addit Contam Part A Chem Anal Control Expo Risk Assess 2016 Aug; 33(8):1324-36.
Nitrofurazone is an antibiotic with carcinogenic properties. Efforts by regulatory authorities to control nitrofurazone from agricultural foods are an important public health measure that have, to some extent, been undermined by widespread use amongst laboratories of the unreliable marker metabolite semicarbazide. This work confirms what has long been suspected, namely that powdered dairy products that are initially free of semicarbazide develop semicarbazide under storage conditions such as occur normally across commercial supply chains. The low ng g(-)(1) levels of semicarbazide formed in this way are insufficient to present any food safety hazard. That such development of a marker metabolite is demonstrated to occur by innocent means effectively invalidates the use of semicarbazide as a marker metabolite for powdered dairy products, and exacerbates the regulatory need for a more suitable analytical methodology. In milk, unlike meat, nitrofurazone is known to remain stable and thus available for analysis in the intact form, rather than necessitating any use of a metabolite or fragment. However, no previous methodology that was capable of achieving the stringent European minimum required performance limit of 1 ng g(-)(1) when using intact nitrofurazone had been described for milk. This work describes a specific methodology using LC-MS/MS for milk and milk powder; it achieves detection of intact nitrofurazone (as well as furazolidone, furaltadone and nitrofurantoin) to levels well below 1 ng g(-)(1). Laboratories will no longer need to use semicarbazide as an unreliable marker metabolite for the analysis of nitrofurazone in dairy products, paving the way for regulatory authorities to better control nitrofurazone abuse with greater confidence.