Food additives contaminants [journal]
- 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 Jul 29.:1-9.
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 Jul 25.:1-13.
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.
- Development of PLA films containing oregano essential oil (Origanum vulgare L. virens) intended for use in food packaging. [JOURNAL ARTICLE]
- Food Addit Contam Part A Chem Anal Control Expo Risk Assess 2016 Jul 25.:1-13.
Consumers' concerns about the environment and health have led to the development of new food packaging materials avoiding petroleum-based matrices and synthetic additives. The present study has developed polylactic acid (PLA) films containing different concentrations of essential oil from Origanum vulgare L. virens (OEO). The effectiveness of this new active packaging was checked for use in ready-to-eat salads. A plasticising effect was observed when OEO was incorporated in PLA films. The rest of the mechanical and physical properties of developed films did not show much change when OEO was included in the film. An antioxidant effect was recorded only for films containing the highest percentages of the active agent (5% and 10%). In addition, films exhibited in vitro antibacterial activity against Staphylococcus aureus, Yersinia enterocolitica, Listeria monocytogenes, Enterococcus faecalis and Staphylococcus carnosus. Moreover, in ready-to-eat salads, antimicrobial activity was only observed against yeast and moulds, where 5% and 10% of OEO was the most effective.
- High-performance liquid chromatography-tandem mass spectrometry method for simultaneous detection of ochratoxin A and relative metabolites in Aspergillus species and dried vine fruits. [JOURNAL ARTICLE]
- Food Addit Contam Part A Chem Anal Control Expo Risk Assess 2016 Jul 21.:1-12.
A simple, sensitive and reliable quantification and identification method was developed for simultaneous analysis of ochratoxin A (OTA) and its related metabolites ochratoxin alpha (OTα), ochratoxin B (OTB) and mellein. The method was assessed by spiking analytes into blank culture media and dried vine fruits. Performance was tested in terms of accuracy, selectivity and repeatability. The method involves an ultrasonic extraction step for culture samples using methanol aqueous solution (7:3, v/v); the mycotoxin is quantified by high-performance liquid chromatography coupled with electrospray ionisation and triple quadrupole mass spectrometry (LC-ESI-MS/MS). The recoveries were 74.5-108.8%, with relative standard deviations (RSDs) of 0.4-8.4% for fungal culture. The limits of detection (LODs) were in the range of 0.03-0.87 μg l(-)(1), and the limits of quantification (LOQs) ranged from 0.07 to 2.90 μg l(-)(1). In addition, the extraction solutions and clean-up columns were optimised specifically for dried vine fruit samples to improve the performance of the method. Methanol-1% sodium bicarbonate extraction solution (6:4, v/v) was determined to be the most efficient. Solid-phase extraction (SPE) was performed as a clean-up step prior to HPLC-MS/MS analysis to reduce matrix effects. Recoveries ranged from 80.1% to 110.8%. RSDs ranged from 0.1% to 3.6%. LODs and LOQs ranged from 0.06 to 0.40 μg kg(-)(1) and from 0.19 to 1.20 μg kg(-)(1), respectively. The analytical method was established and used to identify and quantify OTA and related compounds from Aspergillus carbonarius and Aspergillus ochraceus in cultures and dried vine fruits. The results showed that A. carbonarius produced OTα, OTB and OTA, whereas A. ochraceus produced OTB, OTA and mellein after 7 days of cultivation. Of 30 commercial samples analysed, 10 were contaminated with ochratoxins; OTB, OTα and mellein were also detected in different samples.
- Immunofluorescence detection of pea protein in meat products. [JOURNAL ARTICLE]
- Food Addit Contam Part A Chem Anal Control Expo Risk Assess 2016 Jul 21.:1-7.
In this study we developed an immunofluorescence method to detect pea protein in meat products. Pea protein has a high nutritional value but in sensitive individuals it may be responsible for causing allergic reactions. We produced model meat products with various additions of pea protein and flour; the detection limit (LOD) of the method for pea flour was 0.5% addition, and for pea protein it was 0.001% addition. The repeatabilities and reproducibilities for samples both positive and negative for pea protein were all 100%. In a blind test with model products and commercial samples, there was no statistically significant difference (p > 0.05) between the declared concentrations of pea protein and flour and the immunofluorescence method results. Sensitivity was 1.06 and specificity was 1.00. These results show that the immunofluorescence method is suitable for the detection of pea protein in meat products.
- Improved analysis of Monascus pigments based on their pH-sensitive Uv-Vis absorption and reactivity properties. [JOURNAL ARTICLE]
- Food Addit Contam Part A Chem Anal Control Expo Risk Assess 2016 Jul 19.
Monascus pigments, a mixture of azaphilones mainly composed of red, orange and yellow pigments, are usually prepared in aqueous ethanol and analyzed by ultraviolet-visible spectroscopy. The pH of aqueous ethanol used during sample preparation and analysis has never been considered a key parameter to control; however, this study shows that the ultraviolet-visible spectra and color characteristics of the six major pigments are strongly influenced by the pH of the solvent employed. In addition, the increase of solvent pH resulted in a remarkable increase of the amination reaction of orange pigments with amino compounds, and at higher pH (≥ 6.0) a significant amount of orange pigment derivatives rapidly form. The consequent impact of these pH-sensitive properties on pigments analysis is further discussed. Based on the presented results, we propose that the sample preparation and analysis of Monascus pigments should be uniformly performed at low pH (≤ 2.5) to avoid variations of UV-Visible spectra and the creation of artifacts due to the occurrence of amination reactions, and ensure an accurate analysis that truly reflects pigment characteristics in the samples.