Development of a DNA Barcoding-Like Approach to Detect Mustard Allergens in Wheat Flours.

The spread of food allergens is a topic of global importance due to its impact on public health. National and International regulations ask food producers and manufacturers to declare product compositions on the label, especially in case of processed raw materials. Wheat flour (Triticum aestivum) can be contaminated by a wide range of species belonging to the Brassicaceae in the field or during grain harvests, storage, and processing. Among them, mustards (Brassica nigra, Brassica juncea and Sinapis alba) are well known allergenic species. Often, food quality laboratories adopt an ELISA approach to detect the presence of mustard species. However, this approach shows cross-reactivity with other non-allergenic species such as Brassica napus (rapeseed). In the last few years, DNA barcoding was proposed as a valid identification method, and it is now commonly used in the authentication of food products. This study aims to set up an easy and rapid DNA-based tool to detect mustard allergenic species. DNA barcoding (matK and ITS2) and chromosome markers (A6, B, C1 genome regions) were selected, and specific primers were validated on incurred reference food matrices. The developed test was proven to be able to distinguish mustard from rapeseed and wheat, overcoming cross-reactivity with Brassica napus.

Ion mobility spectrometry coupled to gas chromatography: A rapid tool to assess eggs freshness.

Egg products freshness is a crucial problem for the production of safe and high quality food. Ion Mobility Spectrometry (IMS) coupled to Gas Chromatography (GC), provides a rapid, sensitive, cost-effective tool for the detection of freshness issues. A chemometric model was created recording the volatile fingerprints of the different egg products batches, analyzed as fresh, then left at room temperature and daily controlled: 97% was correctly predicted by the model. Beside this, a selection of chemical marker compounds, coherently related with eggs thermal degradation processes, was also identified through the exploitation of Solid-Phase Micro Extraction Gas Chromatography (SPME-GC-MS) technique and associated to the parallel IMS volatile fingerprinting. The GC-IMS system was successfully challenged with the analysis of mixtures in which the predominant component was fresh egg product and different aged eggs were progressively added as adulterants, certifying the reliability of the method also for the detection of sharper fraudulent activities.

Determination of Ochratoxin A in Rye and Rye-Based Products by Fluorescence Polarization Immunoassay.

A rapid fluorescence polarization immunoassay (FPIA) was optimized and validated for the determination of ochratoxin A (OTA) in rye and rye crispbread. Samples were extracted with a mixture of acetonitrile/water (60:40, v/v) and purified by SPE-aminopropyl column clean-up before performing the FPIA. Overall mean recoveries were 86 and 95% for spiked rye and rye crispbread with relative standard deviations lower than 6%. Limits of detection (LOD) of the optimized FPIA was 0.6 µg/kg for rye and rye crispbread, respectively. Good correlations (r > 0.977) were observed between OTA contents in contaminated samples obtained by FPIA and high-performance liquid chromatography (HPLC) with immunoaffinity cleanup used as reference method. Furthermore, single laboratory validation and small-scale collaborative trials were carried out for the determination of OTA in rye according to Regulation 519/2014/EU laying down procedures for the validation of screening methods. The precision profile of the method, cut-off level and rate of false suspect results confirm the satisfactory analytical performances of assay as a screening method. These findings show that the optimized FPIA is suitable for high-throughput screening, and permits reliable quantitative determination of OTA in rye and rye crispbread at levels that fall below the EU regulatory limits.