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Due to their potential adverse effects on human health, the use of carbadox and olaquindox in feedingstuffs was prohibited by the European Union since 1998. In this work, highly luminescent quantum dot beads (QBs) were synthesized by encapsulating CdSe/ZnS and used as novel fluorescent probes in the immunochromatographic assay (ICA) for simultaneous and quantitative determination of metabolites of olaquindox (3-methylquinoxaline-2-carboxylic acid, MQCA) and carbadox (quinoxaline-2-carboxylic, QCA). The fluorescence intensities of the test lines were recorded using a fluorescence strip reader. The 50% of inhibition for MQCA and QCA was shown to be 8.1 and 10.6 μg L−1, respectively. The whole assay process can be accomplished within 10 min. The immunosensor was used to analyze spiked samples, and analyte intra- and inter-assay recovery rates ranged from 78.7 to 92.2% for MQCA and 80.6 to 95.8% for QCA, and coefficients of variation were all below 12%. The incurred tissues samples were assayed using both QB-based ICA and commercial ELISA kit and were further confirmed with LC-MS/MS. The QB-based ICA results exhibited good agreement with both commercial ELISA and LC-MS/MS methods.

A polyvinylidene fluoride membrane-based dot immunoassay using nanobody (Nb) for rapid, qualitative, and visual detection of ochratoxin A (OTA) in cereals was developed. On the basis of optimal assay conditions, the cut-off level of this method assessed visually was 5 μg/kg for OTA, and the final results were obtained within 20 min. This method was simple with no time-consuming cleanup procedure. Good accuracy and reproducibility were obtained in recovery experiments. Results of the Nb-based dot ELISA are in agreement with the ELISA kit, except for samples that were negative for OTA presence assessed through Nb-based dot ELISA but found positive through the ELISA kit. These results indicated that the developed method could be a useful on-site screening tool for rapid detection of OTA in cereals without special instrument.

The clarification or fining of wine removes undesired substances (mainly proteins, phenols, and tannins), which would roil the wine and cause bitterness and astringency. A common fining agent, egg white, can be directly added to wine through the inlet of a circulating pump, but more typically egg white comes as commercial preparation in powdered form (commercially named egg albumin). Skimmed milk or more frequently purified caseinates are used to remove bitterness and hardness of white wine and sherry. Both egg white and caseinates are fining agents with optimal enological properties, but their residues could represent a risk for subjects suffering from food allergy. The rules for allergen labeling were detailed in Directives 2003/89/EC, and Directive 2005/26/EC established a list of food ingredients provisionally excluded from labeling, that included wine fining agents. Extended till June 2012, wine labeling exemption can be now maintained only if (1) egg and milk derivatives are not used and cross-contamination is under control; and (2) wine clarified with such products is negative for the presence of residues using techniques with detection and quantification limits of 0.25 and 0.5 ppm, respectively. Analytical requirements were defined in the OIV resolution 427–2010 (OIV 2010) modified by OIV/COMEX 502–2012 (OIV 2012). On the basis of a previous experience, an interlaboratory collaborative trial was organized to validate a commercial ELISA kit designed to measure allergenic residues in red wine fined with egg white proteins. In the meantime, the performance of the commercial caseinate ELISA kit for white wine was rechecked according to the new limit of detection and limit of quantification values, recommended by OIV in 2012. The collaborative interlaboratory studies showed that both ELISA kits had good reproducibility, repeatability, and robustness in detecting residues of allergenic fining agents in wine, in good agreement with the requirements of the OIV resolution 427–2010 modified by OIV/COMEX 502–2012.