Development of a sensitive sandwich ELISA with broad species specificity for improved fish allergen detection.

A sensitive Enzyme-linked Immunosorbent Assay (ELISA) with improved broad species specificity was developed for the detection of southern hemisphere fish residues in processed foods. The polyclonal antibodies were raised against parvalbumins from 13 fish species representing 7 fish orders selected for their molecular diversity and immunoreactivity profile. The optimized ELISA-2 (based on the rabbit capture antibody (RB#4) - sheep detection antibody (S2#4) pair) displayed an improved detection limit of 0.6 µg/L (3.7 µg of /kg). Our immunoreactivity-directed species selection approach in the strategized antibody production significantly improved the detection of no or weakly immunoreactive fish species previously not detected immunochemically. Of 37 commercially important fish species tested, the ELISA-2 could detect 28 fish species (76%). The optimized sample extraction with a buffer additive achieved good protein recoveries of 87.2 - 117.3% (within the AOAC recommended range). The ELISA-2 was able to detect fish residues in five highly processed food products.

Peanut Can Be Used as a Reference Allergen for Hazard Characterization in Food Allergen Risk Management: A Rapid Evidence Assessment and Meta-Analysis.

Regional and national legislation mandates the disclosure of "priority" allergens when present as an ingredient in foods, but this does not extend to the unintended presence of allergens due to shared production facilities. This has resulted in a proliferation of precautionary allergen ("may contain") labels (PAL) that are frequently ignored by food-allergic consumers. Attempts have been made to improve allergen risk management to better inform the use of PAL, but a lack of consensus has led to variety of regulatory approaches and nonuniformity in the use of PAL by food businesses. One potential solution would be to establish internationally agreed "reference doses," below which no PAL would be needed. However, if reference doses are to be used to inform the need for PAL, then it is essential to characterize the hazard associated with these low-level exposures. For peanut, there are now published data relating to over 3000 double-blind, placebo-controlled challenges in allergic individuals, but a similar level of evidence is lacking for other priority allergens. We present the results of a rapid evidence assessment and meta-analysis for the risk of anaphylaxis to a low-level allergen exposure for priority allergens. On the basis of this analysis, we propose that peanut can and should be considered an exemplar allergen for the hazard characterization at a low-level allergen exposure.

Development and evolution of risk assessment for food allergens.

The need to assess the risk from food allergens derives directly from the need to manage effectively this food safety hazard. Work spanning the last two decades dispelled the initial thinking that food allergens were so unique that the risk they posed was not amenable to established risk assessment approaches and methodologies. Food allergens possess some unique characteristics, which make a simple safety assessment approach based on the establishment of absolute population thresholds inadequate. Dose distribution modelling of MEDs permitted the quantification of the risk of reaction at the population level and has been readily integrated with consumption and contamination data through probabilistic risk assessment approaches to generate quantitative risk predictions. This paper discusses the strengths and limitations of this approach and identifies important data gaps, which affect the outcomes of these predictions. These include consumption patterns among allergic individuals, analytical techniques and their application, severity-dose relationships, and the impact of extraneous factors which alter an individual's physiology, such as infection or exercise. Nevertheless, application of these models has provided valuable insights, leading to further refinements and generating testable hypotheses. Their application to estimate the risk posed by the concurrent consumption of two potentially contaminated foods illustrates their power.