Hamide Z. Senyuva

Detection of porcine DNA in gelatine and gelatine-containing processed food products-Halal/Kosher authentication.

A commercially available real-time PCR, based on a multi-copy target cytochrome b (cyt b) using porcine specific primers, has been validated for the Halal/Kosher authentication of gelatine. Extraction and purification of DNA from gelatine were successfully achieved using the SureFood® PREP Animal system, and real-time PCR was carried out using SureFood® Animal ID Pork Sens kit. The minimum level of adulteration that could be detected was 1.0% w/w for marshmallows and gum drops. A small survey was undertaken of processed food products such as gum drops, marshmallows and Turkish delight, believed to contain gelatine. Of fourteen food products from Germany, two samples were found to contain porcine gelatine, whereas of twenty-nine samples from Turkey twenty-eight were negative. However, one product from Turkey contained porcine DNA and thus was not Halal, and neither was the use of porcine gelatine indicated on the product label.

Future perspectives in Orbitrap™-high-resolution mass spectrometry in food analysis: a review

A literature search from 2007 to 2014 was conducted to identify publications where principally LC-Orbitrap™-high-resolution mass spectrometry (HRMS) has been employed in food analysis. Of a total of 212 relevant references, only 22 papers were from 2007–10, but in subsequent years there has been a steady growth in publications with 38–55 relevant papers being published each year from 2011 to 2014. In the food safety area, over 50% of the published papers were equally divided between pesticides, veterinary drug residues and natural toxins (including mycotoxins) focused primarily on multi-analyte target analysis. LC-Orbitrap-HRMS was also found to be increasingly important for the analysis of bioactive substances, principally phenolic compounds in foods. A number of studies reported for the first time the identification of new fungal metabolites, predominantly various conjugated forms of known mycotoxins. Novel process contaminants were also identified by LC-Orbitrap-HRMS, as were various substances used for food adulteration and bioactive substances in herbal products and dietary supplements. Untargeted analysis is seen as a major future trend where HRMS plays a significant role. Retrospective analysis of scanned high-resolution mass spectra in conjunction with relevant databases can provide new insights. Metabolomics is also being increasingly used where foods are being profiled through fingerprinting using HRMS. All evidence points towards future growth in the number of applications of HRMS in food safety and quality, as the power of this technique gains wider recognition. Graphical Abstract

Meat species identification and Halal authentication using PCR analysis of raw and cooked traditional Turkish foods

The method performance characteristics of commercially available PCR kits for animal species identification were established. Comminuted meat products containing different levels of pork were prepared from authentic beef, chicken, and turkey. These meat products were analysed in the raw state and after cooking for 20 min at 200 °C. For both raw and cooked meats, the PCR kit could correctly identify the animal species and could reliably detect the addition of pork at a level below 0.1%. A survey of 42 Turkish processed meat products such as soudjouk, salami, sausage, meatball, cured spiced beef and doner kebap was conducted. Thirty-six samples were negative for the presence of pork (<0.1%) and four were found to be correctly labelled as containing pork. However, one sausage sample was labelled as containing 5% beef, but beef DNA was not detected and a meatball sample labelled as 100% beef was found to contain chicken. Another turkey meatball sample was predominantly chicken.

Screening of plant and fungal metabolites in wheat, maize and animal feed using automated on-line clean-up coupled to high resolution mass spectrometry.

A wide range of plant and fungal metabolites can occur in cereals and feed but only a limited number of target compounds are sought. This screening method is using a database of over 600 metabolites to establish contamination profiles in food and feed. Extracts were injected directly into an automated turbulent flow sample clean-up system, coupled to a liquid-chromatography-high-resolution-mass-spectrometer (Orbitrap). Compound identification criteria for database searching were defined and the approach was validated by spiking plant and fungal metabolites into cereals and feed. A small survey of market samples (15) and quality control materials (9) of maize, wheat and feed was conducted using this method. Besides regulated and known secondary metabolites, fumiquinazoline F, fusarochromanone and dihydrofusarubin were identified for the first time in samples of maize and oats. This method enables clean-up of crude extracts within 18min and screening and confirmation of a wide range of different compound classes.

Determination of fusarium mycotoxins in wheat, maize and animal feed using on-line clean-up with high resolution mass spectrometry.

An automated method involving on-line clean-up and analytical separation in a single run using TurboFlow™ reversed phase liquid chromatography coupled to a high resolution mass spectrometer has been developed for the simultaneous determination of deoxynivalenol, T2 toxin, HT2 toxin, zearalenone and fumonisins B1 and B2 in maize, wheat and animal feed. Detection was performed in full scan mode at a resolution of Ru2009=u2009100,000 full width at half maximum with high energy collision cell dissociation for the determination of fragment ions with a mass accuracy below 5u2009ppm. The extract from homogenised samples, after blending with a 0.1% aqueous mixture of 0.1% formic acid/acetonitrile (43:57) for 45u2009min, was injected directly onto the TurboFlow™ (TLX) column for automated on-line clean-up followed by analytical separation and accurate mass detection. The TurboFlow™ column enabled specific binding of target mycotoxins, whereas higher molecular weight compounds, like fats, proteins and other interferences with different chemical properties, were removed to waste. Single laboratory method validation was performed by spiking blank materials with mycotoxin standards. The recovery and repeatability was determined by spiking at three concentration levels (50, 100 and 200% of legislative limits) with six replicates. Average recovery, relative standard deviation and intermediate precision values were 71 to 120%, 1 to 19% and 4 to 19%, respectively. The method accuracy was confirmed with certified reference materials and participation in proficiency testing.

Coupled Turbulent Flow Chromatography: LC–MS/MS Method for the Analysis of Pesticide Residues in Grapes, Baby Food and Wheat Flour Matrices

This paper describes an on-line sample preparation method for the simultaneous determination of 48 pesticides in grapes, baby food and wheat flour matrices. Target pesticides were selected to represent a wide variety of chemical structures and three typical matrices were selected. Turbulent flow chromatography was applied for on-line sample cleanup directly coupled to LC–MS/MS. The aim of the method was to reduce total analysis time, eliminate manual laboratory work, provide clean extracts and achieve reproducible results. Single laboratory method validation was conducted establishing limits of detection between 0.8 and 6.0xa0ngxa0g−1 for baby food, and 0.8–10.3xa0ngxa0g−1 for other matrices. Within-day precision values varied between 4 and 18xa0%, while between-day precisions were in the range 5–22xa0%. Method recovery ranged from 67 to 124xa0%, and method accuracy was demonstrated by analysis of external quality control samples. The method was also tested on 24 different survey samples from both bio and organic origin. The method was shown to be convenient, fast and fit for purpose in meeting regulatory requirements for pesticide residue monitoring.

Multiresidue automated turbulent flow online LC-MS/MS method for the determination of antibiotics in milk

A fast and reliable multiresidue method is reported for the identification and quantification of 36 different compounds from seven different classes of antibiotics (aminoglycosides, sulfonamides, macrolides, quinolones, tetracyclines, lincosamides and trimethoprim) in milk. Automated online sample cleanup was applied using turbulent flow chromatography (Transcend TLX system), directly coupled to a mass spectrometer (MS/MS) for sensitive and specific detection. The method involved a simple extraction/protein precipitation using acetonitrile, followed by centrifugation and filtration. After this preliminary step, the extract was injected into the TLX-ESI-MS/MS using optimised turbulent flow and liquid chromatography (LC) conditions. Single-laboratory validation of the method was carried out according to the Directive 2002/657/EC, clearly demonstrating the suitability of this method for quantitative determination of this wide range of antibiotics in milk. A small survey, which covered milk samples of different origin and varied fat content, demonstrated the robustness of this method and its suitability for enforcement purposes.

Analysis and critical comparison of food allergen recalls from the European Union, USA, Canada, Hong Kong, Australia and New Zealand

ABSTRACT As part of a European Union-funded project (FP7) developing ‘Integrated approaches to food allergen and allergy management’, a database was constructed based on publicly available information on food allergen recalls in Europe, North America, Hong Kong, Australia and New Zealand. Over 2000 entries were made into the database. The database covers a 4-year period from 2011 to 2014 and each entry is categorised into food type (two different classifications), identified allergen and cause where indicated by the authorities. Across different authorities, by far the biggest incidence of undeclared allergens occurred in the food categories of prepared dishes and snacks (range = 12–53%), and cereals and bakery products (range = 14–25% of all recalls and/or alerts). The biggest incidence of undeclared allergens, according to the information from most authorities, occurred for milk and milk products (16–31% of all products with recall or alert), followed by cereals containing gluten (9–19%), soy (5–45%), and egg and egg products (5–17%). Although 42–90% of the products with recalls/alerts were explained as being ‘Not indicated on the label’, this is a generic explanation of cause and does not provide much insight into the causes of the recall/alerts. However, 0–17% of products with recalls/alerts could be coded as caused by the unintended presence of an allergen as the probable result of cross-contact in production. Construction of the database of allergen recalls has provided some important lessons and recommendations to the authorities are made in this paper in terms of the harmonisation of the reporting of allergen recalls into a more standardised format.

A survey of the use of soy in processed Turkish meat products and detection of genetic modification

To screen for possible illegal use of soybeans in meat products, the performance characteristics of a commercial polymer chain reaction (PCR) kit for detection of soybean DNA in raw and cooked meat products were established. Minced chicken and beef products containing soybean at levels from 0.1% to 10.0% were analysed by real-time PCR to amplify the soybean lectin gene. The PCR method could reliably detect the addition of soybean at a level of 0.1%. A survey of 38 Turkish processed meat products found only six samples to be negative for the presence of soybean. In 32 (84%) positive samples, 13 (34%) contained levels of soy above 0.1%. Of soybean positive samples, further DNA analysis was conducted by real-time PCR to detect whether genetically modified (GM) soybean had been used. Of 32 meat samples containing soybean, two samples were positive for GM modification.

Surveys of aflatoxin B1 contamination of retail Turkish foods and of products intended for export between 2007 and 2009

Surveys were carried out between 2007 and 2009 to determine the aflatoxin B1 content of 3345 commercial Turkish foodstuffs supplied by producers for testing for their own purposes or for export certification. To simplify the reporting of data, foods were categorized as: 1, high sugar products with nuts; 2, nuts and seeds; 3, spices; 4, grain; 5, cocoa products; 6, dried fruit and vegetables; 7, processed cereal products; 8, tea; and 9, baby food and infant formula. Aflatoxin analysis was carried out by high-performance liquid chromatography with fluorescence detection after immunoaffinity column clean-up, with a recoveries ranging from 91% to 99%, depending on the matrix. Of the 3345 samples analysed, 94% contained aflatoxin B1 below the European Union limit of 2 µg kg−1, which applies to nuts, dried fruit, and cereals products. The 6% of the 206 contaminated samples were mainly nuts and spices. For pistachios, 24%, 38%, and 42% of the totals of 207, 182, and 24 samples tested for 2007, 2008 and 2009, respectively, were above 2 µg kg−1, with 50 samples containing aflatoxin B1 at levels ranging from 10 to 477 µg kg−1.