Identifying allergens in springtime treats

Author: Joanne Ballantyne

The decoration of eggs for springtime celebrations is an activity that can bring joy and life into a household. For many, it can conjure up memories of baskets full of sweet goodies and egg hunts through the woods in springtime. However, spring can bring with it a number of allergy symptoms – typically from pollen. But for a growing percentage of people, allergies to eggs themselves can present a significant issue – one that is estimated to affect up to 2.5% [1] of children worldwide. It is widely acknowledged that incidences of food allergy are on the rise, and with the number of allergy sufferers growing, identifying allergens in foodstuffs is more important than ever.

As food matrices are notoriously complex mixtures, there is a continuing need for a discovery-based omics approach that can confidently identify allergens in minute traces. By doing so, food manufacturers can clearly label their products, preventing unpleasant surprises down the line. Ion mobility – mass spectrometry (IMS-MS) has shown remarkable ability for this purpose.

The technology keeping us safe

Combining ion mobility spectrometry (IMS) with mass spectrometry (MS), IMS-MS ionizes and separates sample molecules on the basis of size, shape, charge, mass and mass-to-charge (m/z) ratio. By lending the ability to measure collisional cross section (CCS) values, IMS provides an additional molecular identifier that is crucial for distinguishing between isomeric and isobaric compounds. Furthermore, IMS increases peak capacity and helps distinguish between background signal and noise, simplifying analysis and increasing confidence in identification. As a result of the amazing benefits IMS offers when interfaced with MS, there is increasing interest into its use for detecting trace allergens in food.

IMS-MS for egg allergen detection

Food allergies arise from an abnormal immunological reaction to certain ingredients – when they are in correctly identified as a threat and treated accordingly by the body. Proteins are common culprits, and egg-based proteins in particular can often trigger allergic reactions. In springtime, egg consumption spikes, [5] but all through the year a significant number of processed foods contain egg as a raw ingredient. As a result, the ability to detect proteins and assess changes to their structure throughout the manufacturing cycle is crucial.

A recent study leveraged IMS-MS technology to identify and quantify known allergenic proteins in raw and cooked egg samples. Proteins extracted from raw and cooked eggs were digested using trypsin, and label-free protein expression data could then be acquired using IMS-MS technology. A total of 95 proteins were identified in raw samples, and 84 in cooked. The results from the study showed that ion mobility increased specificity, giving rise to cleaner spectra and enhanced separation of similar species. This is significant, as food samples are often highly complex mixtures that can be difficult to comprehensively analyze. IMS-MS was able to detect egg allergen ovomucoid (OVM), the dominant allergen in hen’s egg, [6] at a trace concentration of 1ppm.

The technology also proved effective when used to investigate a processed cake mix. Although egg proteins were the focus of the study, allergens relating to other proteins were also detected, highlighting the potential for a multi-allergen screening method using IMS-MS technology. [7]

Future outlook

For allergy sufferers, a simple label can mean the difference between life and death. As a result, robust analytical technologies capable of detecting minute concentrations of allergens in complex food samples are critical. IMS-MS has demonstrated the unique advantages it offers for this purpose in a recent study, increasing confidence in allergen identification using a label-free approach. The results from the research further indicate the value of IMS-MS technology for studies of non-egg-based allergens, widening the technology’s potential applications to encompass studies of other allergenic proteins

With up to 2.5% of children suffering from egg allergies and a predicted rise in allergy sufferers, appropriate screening processes for allergens in processed foodstuffs are more important than ever. It is the crucial first step towards manufacturers clearly labelling the allergen content in their products, minimizing unpleasant surprises. As we head into springtime celebrations, and egg cartons fly off the shelves – along with processed cake batters that will be transformed into delicious bakes – let’s all consider the technology keeping allergy sufferers safe from accidental harm.

Further reading