Food allergen detection by mass spectrometry: the role of systems biology.

Stephen R Quake,Derek Croote

doi:10.1038/npjsba.2016.22

Abstract

Food allergy prevalence is rising worldwide, motivating the development of assays that can sensitively and reliably detect trace amounts of allergens in manufactured food. Mass spectrometry (MS) is a promising alternative to commonly employed antibody-based assays owing to its ability to quantify multiple proteins in complex matrices with high sensitivity. In this review, we discuss a targeted MS workflow for the quantitation of allergenic protein in food products that employs selected reaction monitoring (SRM). We highlight the aspects of SRM method development unique to allergen quantitation and identify opportunities for simplifying the process. One promising avenue identified through a comprehensive survey of published MS literature is the use of proteotypic peptides, which are peptides whose presence appears robust to variations in food matrix, sample preparation protocol, and MS instrumentation. We conclude that proteotypic peptides exist for a subset of allergenic milk, egg, and peanut proteins. For less studied allergens such as soy, wheat, fish, shellfish, and tree nuts, we offer guidance and tools for peptide selection and specificity verification as part of an interactive web database, the Allergen Peptide Browser (http://www.AllergenPeptideBrowser.org). With ongoing improvements in MS instrumentation, analysis software, and strategies for targeted quantitation, we expect an increasing role of MS as an analytical tool for ensuring regulatory compliance.

Highlights

Food allergy prevalence is rising[1] and food allergies are estimated to affect up to 8% of children and 5% of adults.[2]
Unhelpful precautionary food labeling practices paired with growing worldwide food allergy prevalence motivates the development of an analytical workflow capable of multiplexed allergen quantitation in processed food
Food allergens such as wheat, soy, tree nuts, fish, and shellfish lie at one end of the spectrum, where insufficient published data necessitates further research before sets of proteotypic peptides are established

Summary

INTRODUCTION

Food allergy prevalence is rising[1] and food allergies are estimated to affect up to 8% of children and 5% of adults.[2]. More worrying was that 11% of cookies and 25% of chocolate without advisory labeling tested positive for peanut.[10] In another example, the US Food and Drug Administration found evidence of milk in 75% of chocolate products with advisory labeling and evidence of milk even in products without advisory labeling or with dairy-free claims.[11] In some cases, precautionary allergen labeling is representative of the true risk; manufacturers are incentivized to apply such labeling liberally in attempt to avoid litigation.[12] Some phrases have reached such ubiquity that parents of allergic children report ignoring them.[13,14,15] More accurate labeling through quantitative allergen testing would improve quality of life for both allergic patients and their caregivers, but first analytical, institutional, and regulatory challenges must be overcome transparently and with accountability to the numerous stakeholders involved.

METHODS

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SRM METHOD DEVELOPMENT

Findings

CONCLUSION