Tag Archives: peanuts

Emily Kaufman, Emport, Allergens
Allergen Alley

Matrix Matters: Why Allergen Test Kits Are Only Half the Story

By Emily Kaufman
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Emily Kaufman, Emport, Allergens

On-site rapid tests for allergens are an important part of any manufacturing facility’s allergen control plan. Several companies offer allergen test kits for day-to-day use, and it can be hard to tell the differences between them or determine which is the best fit for a given facility. What’s a busy QA professional to do?

One of the most overlooked factors when choosing an allergen test kit actually has almost nothing to do with the test kit itself. Instead, it’s much closer to home: The matrices being tested are just as—if not more—important to consider than the test kit itself.

Before you commit to any allergen test kit, you should talk to someone extensively about the types of products you plan to test. There are a variety of surprising and counterintuitive ways that your matrices can impact the functionality of a test, and you’ll save time and money by understanding information BEFORE you start testing. Below, we’ll review some of the most common matrix challenges.

High Fat Matrices

fruit pops, allergensLet’s imagine a facility that makes ice cream and sorbet. Let’s assume they make a gourmet strawberry ice cream and a fat-free strawberry sorbet, both of which ought to be peanut-free—but since some of the ingredients come from a supplier who also works with peanuts, the QA team decides to run a rapid peanut test on the strawberry products.

Much to the team’s surprise, the sorbet tests positive for peanut but the ice cream does not. What could be happening? Of course, the simplest explanation is possible: The sorbet has peanut residue in it and the ice cream does not. However, there’s another, trickier possibility: They could have the same amount of peanut residue, but the full-fat ice cream could inhibit the test kit’s ability to detect the allergen.

In general, the higher the fat content of your matrices, the higher the detection limit on your test kit. It’s an imprecise spectrum: Using rapid tests to find traces of allergenic protein on an oil is nearly impossible, on fat-rich items like ice cream or cream-based soups it’s a challenge, on items with little or no fat it shouldn’t be an issue. That isn’t to say there couldn’t be other issues with low-fat items, as we’ll review below.

Matrices Processed with High Heat

peanuts, allergensLet’s say our ice cream facility starts making a peanut-butter-swirl flavor. Perhaps they will begin testing their rinsewater for peanut residue after running that flavor, to ensure satisfactory cleaning. The kit they use says it can detect peanut allergen to 5 ppm, and rinsewater is not a high-fat matrix, so they should be good, right?

In this exact example, it’s probably just fine. However, it’s important for the QA team to consider the temperature at which peanuts were roasted. While raw peanut might be detectable at 5 ppm, roasted peanuts could have a detection limit that is much higher. In fact, very strongly roasted peanuts could only be detectable at levels of 500 ppm or more. This doesn’t mean there is no reason to test—but it’s important to know that many antibody-based tests will respond differently to an allergen processed with high heat than one that is raw. The same detection challenge can sometimes be seen with canned or tinned items that are subjected to high heat in processing.

Fermented or Hydrolyzed Matrices

Two of the trickiest items when it comes to allergen detection are soy sauce and fish sauce. In both of these condiments—and many other common ingredients subjected to these types of processing—the allergenic material is subjected to heavy modification. As proteins get folded and broken in unpredictable ways, they become more challenging for antibody-based test kits to detect. In fact, soy sauce and fish sauce are nearly undetectable by most kits.

When validating a cleaning process after using one of these ingredients, often the safest thing to do is to test for a different allergen—formulated in a simpler way—that is also present. Sufficient cleaning after a product made with fish sauce and breadcrumbs, for example, could be proven with a gluten kit; that second allergen will be unaffected by the fermented allergens in the recipe.

Matrices without Multiple Proteins

Some kits look for a variety of proteins commonly found within one allergen. Other times, though, each test kit will be looking for one specific protein. It’s important to confirm that the allergenic protein your facility works with is in fact an allergenic protein that your test kit is trained to recognize.

Perhaps the most common FALCPA allergen where this plays a role is milk. While there are a number of proteins in milk, casein is the most common and accounts for approximately 80% of the protein in milk, making it a common target for allergen test kits (both rapid and ELISA). The remaining 20% of protein is comprised of various whey proteins, most commonly beta-lactoglobulin.

In the case of our ice cream and sorbet facility mentioned above, a kit that detects casein OR beta-lactoglobulin OR both proteins together could be suitable for confirming that the sorbet is truly milk-free. However, there are other types of product that contain only whey proteins, which are a popular way to increase protein content in a variety of foods and beverages. If a facility that works exclusively with whey proteins uses a kit that only detects casein, they will never have a true understanding of their allergen contamination risk.

Another challenging FALCPA allergen is fish, as there are many different species of fish with quite divergent protein structures. If you are testing for fish contamination, it’s important to understand which species of fish the test you are considering can detect, and which species may pose a problem. If there is a mismatch between kit and matrix, then you’ll need to find a different way to ensure safety.

How to Troubleshoot Your Matrices

If you are beginning an allergen testing program, find time to talk with the manufacturers of any allergen kits you are considering. You may also want to talk with the representatives of any labs that are doing third party testing for you. Some questions to ask include:

  • What matrices have you validated your tests for?
  • Do you anticipate any issues with my matrices?
  • How should I validate your tests for my products?
  • What factors impact the sensitivity of this kit?
  • Does the detection limit change based on the matrix?

Your kit manufacturer (or third-party testing lab) should make you feel confident that they understand the quirks of your specific matrices—and they should have ideas for how to troubleshoot any challenges that they foresee. If a supplier tells you that their kit will work equally well across all matrices and declines to offer proof that corresponds to your needs, beware (or at least be prepared to conduct rigorous validation on your own). Allergen detection is complicated, and as with so much of life: If it sounds too good to be true, it probably is.

Suresh Neethirajan, University of Guelph
In the Food Lab

Identifying Peanut and Other Allergens Outside the Lab

By Suresh Neethirajan, Ph.D
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Suresh Neethirajan, University of Guelph

Judging the nature and suitability of items we put in our mouths is a task we perform daily, whether it’s due to different taste preferences, being on a diet, or from particular foods not agreeing with our metabolisms. Some foods can trigger mild reactions such as an upset stomach, or more serious skin rashes and outbreaks, from shortness of breath to even death.

Many of us have been somewhere where someone with a peanut allergy has been brought to everyone’s attention. The situation may have been publicized before boarding a plane, at a school where parents are asked to refrain from giving their children any food containing peanut products, or restaurants that clearly indicate which dishes are peanut-free on their menu, or that the kitchen is absent of the legume.

The number of people with food allergies continues to rise, and although many theories have been provided for the increase, the exact cause is unknown. Many foods are documented as being able to produce an allergic reaction—milk, eggs, soy and shellfish, to name a few—but peanuts and gluten are highlighted as major offenders. Canadian government regulations require that manufacturers label products that contain certain allergens, even if they are made in a facility where allergens are in another product.

The Threat of Gluten and Peanuts

Gluten contained in wheat has become a widely avoided food substance, although the reason for this might has more to do with health concerns than allergies. The American College of Allergy, Asthma and Immunology (ACAAI) estimates that 400,000 U.S. school children have a peanut allergy, with many of those also having other food allergies. According to the ACAAI, many children will eventually outgrow most food allergies, but only 20% of those who have a peanut tolerance will outgrow it.

The charity organization Food Allergy Canada states that 2.5 million people suffer from a food allergy in Canada, while 2 in 100 children are susceptible to peanuts causing a reaction. There isn’t a cure for food allergies, so governments and food inspectors have the weighty task of ensuring that commercially produced products are packaged or served with proper labeling and information to protect consumers. This requires constant checking and testing of products that may have come in contact with peanuts or gluten.

New Tool for Food Inspectors

To provide regular analysis, the procedure has been lengthy and expensive, but scientific researchers at Canada’s University of Guelph have developed an apparatus that can identify allergens in a much shorter time span while being considerably more cost effective. The new allergen detector could expedite allergen reporting and possibly reduce the number of allergic reactions through more timely results.

Biosensor, University of Guelph
Schematic of the biosensor for the rapid detection of food allergens. Image courtesy of BioNanoLab, University of Guelph.

Based on the ELISA (enzyme-linked immunosorbent assay) platform that is widely used in diagnostic labs to identify allergens, the new apparatus provides comparable accuracy. The technology has been miniaturized so that equipment is portable, about the size of an audiocassette case, and tests can be conducted on location instead of relying on a lab that may be far away.

An Allergen that Glows

In the case of peanuts, the scientists focused on a prominent allergen named Ara h 1, because it can be identified through non-radioactive fluorescence. Although there are other allergens in peanuts, they don’t share the same property by which they can be identified, as does Ara h 1.

The process requires a small amount of the suspected food to be liquefied in a suspension so that it can be injected using a filter syringe into a silicon-based plate, or chip, of microcapillaries. As the sample passes through tiny tubes of the microfluidic chip using capillary action, it travels through a beam of light from a LED source that is monitored by a specialized camera, which is also a product of the scientists’ work.

The image captures Ara h 1 protein particles that fluoresce when they come in contact with the chemical properties of the suspension. Currently, the camera records the data and sends it to a computer to be analyzed and deciphered with a result being provided within 20 minutes, compared to a conventional lab test that takes up to four hours after a sample has been received.

In a modification to provide an extremely portable system, research is underway to develop an app to enable results via a smartphone. Testing foods in the near future will be as convenient and prompt as holding the detector in one hand and a smartphone in the other so that a restaurant owner, for example, will be assured that dishes are allergen-free before being served to customers.

Imitating the Human System for Detection

To enable the allergen to fluoresce, the compound graphene oxide (GO) was utilized in combination with a bio-sensing component, known as an aptamer. The aptamer acts similarly to antibodies that identify and attach themselves to foreign and hostile elements that enter our blood system. Once a GO-aptamer mixture is attached to the allergen, the light source allows the protein particle to be detected and its image captured electronically.

By altering an aptamer’s composition to identify other allergens, such as gluten, the detector is a versatile piece of scientific equipment for identifying potentially hazardous food ingredients. The developers of the technology are confident that their discovery will change the future of identifying potentially hazardous food components. The final step in the allergen detector’s development seems to be fine tuning the detection process for certain processed foods, such as roasted peanuts, that can alter the composition of Ara H 1 making it less obvious to be identified.

Steward Parnell, PCA, salmonella outbreak

PCA Executives Sentenced: Stewart Parnell Gets Virtually Life in Prison

By Maria Fontanazza
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Steward Parnell, PCA, salmonella outbreak

In what is being called a groundbreaking decision, a federal judge sentenced three executives from the Peanut Corporation of America (PCA) to a combined 53 years in jail for their role in the 2008-2009 Salmonella outbreak. Stewart Parnell, former CEO of the no-longer-operating PCA, has been sentenced to 28 years; his brother, Michael Parnell, was handed 20 years; and Mary Wilkerson, quality assurance manager of the plant, was given 5 years. Convicted last year on 71 counts, Stewart Parnell was facing up to 803 years in prison, but at the age of 61, 28 years is essentially a life sentence.

The culprit of the fatal 2008 Salmonella outbreak was tainted peanut butter paste manufactured by PCA. Nine Americans died, and more than 700 people across 47 states were sickened. The outbreak led to the recall of more than 2,100 products. It was one of the largest food recalls in U.S. history, and the case has garnered national attention.

During yesterday’s sentencing, victims and their families asked U.S. District Court Judge W. Louis Sands to deliver a life sentence to Stewart Parnell; his daughter, Grey Adams, addressed the room, “My dad’s heart is genuine…” and said that her father and their family are “profoundly sorry” for the deadly outbreak. As Parnell addressed the victims in the Georgia courtroom, he made mention of the problems at the plant but did not comment on the emails and company records that indicate he had knowingly shipped tainted product or tampered with any lab records.

Earlier this year STOP Foodborne Illness’ Darin Detwiler commented on the significance of the sentencing in a video interview with Food Safety Tech, stating, “His actions resulted in technically more deaths than that of Charles Manson.”

Moving forward, the bar for accountability at the executive level has been set much higher. Victims, their families, and food safety advocates are applauding the sentencing. What do you think about the decision and its impact on the industry?