Peanut allergen quantification: a tough nut to crack

As part of the National Measurement Laboratory’s 30th anniversary, we’re sharing stories and case studies from the last three decades.

One of our case studies touches on an issue that affects hundreds of thousands of people across the UK alone: peanut allergies. So read on to learn how LGC scientists developed a unique allergen quality control material, which can be used to help protect the people in the UK with a peanut allergy and also help to prevent contamination in the food production process, potentially saving the food industry millions of pounds.

The problem

The prevalence of peanut allergy has nearly doubled in Europe over the past two decades and it now affects around 500,000 people in the UK [1]. Peanut allergy is the most common cause of fatal food allergy reaction. It occurs when the immune system mistakenly identifies peanut proteins as something harmful. The fear of accidental exposure in food reduces the quality of life of peanut allergy sufferers and severely limits the social habits of allergic individuals, their families and even their friends.

SMALL_iStock_000004018390Small peanutsIt is not only those with peanut allergies who have to worry about the risk of allergic reactions or death by anaphylaxis; it also creates problems for businesses. Testing for allergen proteins in food is difficult, as samples usually contain a lot of protein and it can be difficult to separate the allergen protein of interest. This has an impact on the ability of manufacturers and suppliers to adequately label their goods and also has implications for defining threshold levels and detecting food fraud.

All food companies throughout the EU are compelled by law to declare major allergens including peanut, if included in food products as ingredients. The current labelling rules, brought into force in December 2014 by European Regulation 1169/2011 (the EU Food Information for Consumers Regulation, EU FIC) ensure that all consumers are given highlighted information about the use of allergenic ingredients in pre-packed food [2]. This is to make it easier for people with food allergies to identify the foods they need to avoid. The EU FIC also extends to food sold loose or served when eating out. Prevention of cross contamination with peanut through product testing, validation and verification of cleaning, and checking of ‘peanut-free’ products requires exacting testing.

ELISA (enzyme-linked immunosorbent assay), PCR (polymerase chain reaction) and mass spectrometry (MS) methods can be used to detect food allergens, but there are problems obtaining reliable quantitative results with all three. Prior to this project, there were no suitable reference materials available in the form of a food matrix, making it difficult for laboratories and test-kit manufacturers to validate quantitative methods for allergen measurement.

The solution

A quality control (QC) material that is a real food, containing a known amount of specific allergen protein, and is stable and homogenous could assist laboratories in the validation and monitoring of their analysis. Consequently, a project was undertaken by LGC to develop a food matrix peanut allergen QC material.

The chosen matrix was a chocolate dessert product developed for low-dose threshold studies in food allergic individuals in the European research project ‘EuroPrevall’. Two QC materials were prepared by University of Manchester researchers in the form of chocolate dessert product pastes designed to be reconstituted with water before analysis. One material (LGCQC1011) was prepared as a peanut free negative control and the other material (LGCQC1012) was prepared as a positive control with the addition of light roast, partially defatted peanut flour (a commercial food ingredient) to give a peanut protein content of 10 mg kg-1. The pastes were transferred to LGC, packaged in nitrogen-flushed sealed sachets to aid stability and the units were numbered sequentially in fill order. LGC assessed and proved their homogeneity and stability, underpinned by a validation study of the test method using a commercially available ELISA kit (Romer AgraQuant® Peanut kit). The National Measurement System funded the ELISA kit validation studies, and a Technology Strategy Board and LGC co-funded research and development project established the design and production of the QC material.

Impact

Failure in food allergen management means ‘food-allergen’ related incidents are the most common reason for product withdrawals and recalls in the United Kingdom according to the UK Food Standards Agency. The 34 recalls related to allergens in 2010 were estimated to cost stakeholders £10- 15 million. In 2013, the number of Allergy Alerts issued to withdraw food or drink products had risen to 47.

Phil Goodwin, MD of Bio-Check (UK) a food allergen test kit manufacturer, has worked in this area for 30 years and welcomes LGC’s recent initiatives:

“The science of food allergen detection, let alone quantitation, has failed to move forward anything like quickly enough since it began in the late 1980s. The emergence of such high quality QC materials as are being produced by LGC is a significant step forward to a time when all commercial test kits can be demonstrated to show good agreement on allergen levels. LGC are to be applauded for taking on this difficult challenge and I urge all allergen kit producers and analysts to use the material to improve their products and results.”

 

[1] http://www.mrc.ac.uk/news-events/publications/outputs-outcomesand-impact-of-mrc-research-2013-14/

[2] http://allergytraining.food.gov.uk/english/rules-and-legislation/

This blog first appeared as a NML case study on the LGC Group website. To learn more about the NML, visit their site here.

Revolutionising cancer treatment one Array at a time

While the science of pharmacogenomics has been around for years, its popularity is starting to pick up steam as precision medicine and how we treat individual patients becomes more and more common place in the medical world. Geneticists and doctors are fully embracing the fact that our individual genes make us all unique and that these genes hold clues to how each patient’s body will metabolise medications.

Pharmacogenetics, or the study of how people respond differently to medicines due to their genetics, is making a splash lately thanks to companies like Minneapolis, MN-based OneOme, which co-developed its RightMed test with Mayo Clinic. The company collects a patient’s DNA sample using a simple cheek swab that is then analysed at OneOme’s lab with PCR – in this case on LGC’s IntelliQube® – to determine the patient’s genetics.  This information is then used to determine whether the patient has any genetic variations that may cause them to have a certain reaction to a medication. These results give doctors “graphic genetic pinpoint accuracy” on the medications that should work and those likely to be less effective. In simplest terms, these tests, combined with PCR instruments are empowering patients and doctors with information that may not only make their lives better, but also safer. Or as we like to say, science for a safer world.

Take a look at just how much pharmacogenomics is impacting and “revolutionizing” patient care by watching the video here.

 

This story was originally published on the Biosearch Technologies blog.

Food chain resilience in a changing world

A few weeks ago, we were joined by experts and industry leaders at our biennial Government Chemist Conference, and this year’s theme was ‘Food chain resilience in a changing world’.

Attendees were treated to a variety of presentations about food chain resilience from Food Standards Agency, Public Health England, the European Commission’s Joint Research Council, Cambridge University, and many others.

Topics ranged from food crime to genome sequencing and genetics, as well as preparing the food industry for Brexit and systems for fighting fraud.

Among some of the popular topics discussed were meat speciation techniques and food authenticity, which underline current issues surrounding consumer trust in food manufacturing.

Methods for detecting trace amounts of undeclared ingredients in food have evolved enormously in recent years, but incidents still occur. Recent reports suggest that some ‘meat-free’ ready meals have even contained trace amounts of meat, although the exact amount and method of transfer have yet to be determined.

Any food used as an ingredient in a pre-packed processed product, (i.e. in the ‘recipe’) must be declared in the list of ingredients. Adventitious meat cross contamination isn’t generally regarded as deliberate fraud under 1 %. But even below this ‘cut-off’ point there are implications for consumer choice, especially if avoiding meat (vegetarian or vegan preferences), or specific meat species for religious reasons.

When ‘trace’ amounts of a material have been found in food, it suggests adventitious cross contamination (which could be obtained from inadequate cleaning of equipment, for example), rather than intentional adulteration. Particularly with foods that contain many ingredients, like ready meals, this could come from any of the ingredients at any point along the supply chain.

This makes the methodology of detection that much more important, as each technique has its own level of accuracy. For instance, Polymerase Chain Reaction (PCR) screens for the absence or presence of specific DNA within a defined limit of detection, which would require the scientist to know what to look for. Care is required in carrying out these tests and interpretation of the results.  Meanwhile, Next Generation Sequencing (NGS) detects and sequences all DNA material in a sample, which allows for a greater understanding of the makeup of foods. Once the NGS finishes its analysis, millions of sequences can be analysed to identify species, but this method is more expensive and can be resource intensive.

These are just two examples of methods used recently to determine authenticity, but there isn’t uniformity in methods and standards around the world. Now that we are becoming more globally focussed than ever before, in both trade and knowledge sharing, there should be more harmonisation among techniques used in different places. Food supplies might cross several different borders before becoming food; processed, tested and analysed with different standards. It’s important that we have robust systems in place to ensure that food standards and methods for measurement are equal and that all food is both safe and exactly what it claims to be.

And many of the speakers and attendees of the GC Conference are working toward that goal, sharing their expertise on sound science, building systems for detection of fraud, and enforcing stronger regulations for food safety.

Watch the video from the conference, or you can learn more about the speakers and see their presentations here.