Tag Archives: detection

Craig Butt

Preparing for the Proposed EU Ban on PFAS

By Food Safety Tech Staff
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Craig Butt

In February, the European Union (EU) announced a proposed ban on the production, use, and sale of about 10,000 per- and polyfluoroalkyl substances (PFAS). We spoke with Craig Butt, Ph.D., Senior Staff Scientist for Food/Environmental Science at SCIEX to learn more about the proposal, how it may affect the food industry and how companies can begin preparing for more stringent regulations both in the EU and the U.S.

What do food companies need to know about the EU’s proposed ban on PFAS?

Butt: First, it is a proposal at this point and it is open to six-month commentary. About a year from now they will make an official decision. Whatever they decide will slowly be rolled out, but it is a huge and very comprehensive proposed ban that will impact people globally.

We live in an environment of global trade, so this will impact those that manufacture food packaging as well as any food products that might be coming across EU lines. What’s most interesting to me about this is the idea that, in the U.S. there’s a lot of attention on drinking water and drinking water regulations, but to propose banning PFAS in products, that takes the regulations further up the chain.

Is this a true ban on PFAS in the products or are they lowering the threshold from current levels?

Butt: There are two aspects to it. It would set lower limits, but they are also seeking more comprehensive monitoring. Typically, regulation and detection of PFAS has involved specific, targeted sets of compounds.

The problem with PFAS is, it is not like banning or reducing use of a single pesticide, you’re talking about potentially 5,000 different chemicals—depending on how you define them—and maybe even 12,000 different chemicals. So how do you address PFAS as a group? This proposal is trying to address that by looking at not only targeted compounds, but PFAS as a class and trying to understand the control of those compounds as a group.

There is still a lot of work to be done before we see where it falls out. The devil is always in the details, and I know there’s going to be pressure on multiple sides. You’re going to have pressure from one group saying this isn’t strict enough and the other side saying this is too strict and everyone’s going to go bankrupt.

But when you read it and you see the ban on products and certain thresholds in those products, I’m pretty sure that’s going to stay, particularly where they’re looking at total PFAS or total fluorine content. That tells us that we’re going to have to go beyond just looking for a targeted list of compounds and do a better job of characterizing all the fluorine compounds that are in there.

Does the proposal primarily focus on food contact packaging or the food products themselves?

Butt: There is still some clarity needed in terms of what the regulations will look like in the final document, but it seems to be focused more on the source, which would be the food packaging paper and products, rather than the food itself.

Where is the industry now in terms of detection and remediation of PFAS and where will it potentially need to go to meet these new regulations, if passed?

Butt: It is important to remember that there was a time before PFAS were widespread in food packaging, and I do know that companies are making efforts to look for alternatives. Back in the early 2000s when 3M banned Scotch Guard, it wasn’t too long until suitable alternatives were found. In the U.S., some manufacturers—working with the FDA—have agreed to change what’s in their food contact materials. In terms of what the industry has in the warehouse ready to go, it is unclear, but companies have seen the writing on the wall and are taking steps to find alternatives. Still, the move totally away from fluorochemicals will likely be a bit of a shock to those who make them.

The concerns will be whether the non-fluorinated chemicals are as effective as the PFAS, and if they are not will they still be satisfactory? We also need to be cautious as we investigate alternatives because we don’t want to replace these PFAS chemicals with newer chemicals that we don’t yet have knowledge about their toxicology or environmental impact on.

What should people looking at now in terms of investigating new products and understanding what they’re going to need to do in terms of detection?

Butt: Detection is the first step. Some folks may not be aware of what’s in the products they are buying in terms of raw materials. You want to know what’s in your own products and the products you are using. There is a huge risk in terms of public relations and reputation. The last thing a company wants to do is have a third party test their products and find out that there are PFAS in them and have that potential reputational damage, because there are a lot of third parties out there that do that, and they are not afraid to name names.

Are there effective tests available if you want to start checking your packaging?

Butt: Yes, we have gotten very good at measuring extremely low levels as well as reducing some of the impacts on data quality and detection in terms of confirmed detection. We can measure things at trace levels and accurately say that they are there. That’s from a targeted standpoint. But we’re also very good at doing non-targeted work to find some of those unknown PFAS that may not be on a standard monitoring list but can help improve the further characterization of what’s there.

A lot of attention has been on PFOS and PFOA, but if you are only looking at those compounds, then you are doing yourself a disservice because what we know and what we’ve seen through time is that those lists of dangerous compounds only continue to grow. As regulators become aware of their presence and their toxicology and as analytical chemists get better and publish findings of these new compounds in consumer products, then the list will continue to grow.

In terms of the regulatory climate here in the U.S., where do you think we’re headed?

Butt: Back in the late 2000s, the FDA scientists produced some really incredible work looking at PFAS in food packaging and their migration out of that packaging into foods, and we continue to work with them. They are great scientists and they published some groundbreaking research. However, these are not the same scientists who make the regulations.

There have been some voluntary agreements with some of the manufacturers to reduce the use of chemicals that are larger—the long chain compounds—which are more likely to accumulate in human blood. But these EU regulations will put a whole lot more pressure on companies to look at PFAS as a larger class of chemicals.

As companies look for alternatives that are a) effective and b) not dangerous, are leaching tests typically part of testing these new products?

Butt: The EU regulations do have a leaching component for some of the food packaging materials, particularly for plastic food packaging. You do need to assess the leaching from plasticizer compounds. I’m not sure if there’s a similar leeching test for PFAS, because PFAS are a little bit weird in the sense that, in the past, most of the chemicals that we were concerned about were those that were fat soluble. We know that fatty foods like yogurts are very good at pulling out the contaminants from the food packaging, but PFAS are a little bit odd because they like more neutral compounds, ones that have some emulsifying properties to them—not super fatty or super water soluble—so you have to be cautious that the right kind of migration tests are being used and are fully applicable for these compounds.

One of the things that makes PFAS so interesting is that they don’t behave like our traditional hydrophobic organic contaminants. They don’t build up in your fat. Years ago, when we were worried about DDT and PCBs and some of those other chlorinated pesticides it was because they build up in your fat. But PFAS build up in the blood, kidney and liver, which from a chemical standpoint is interesting but it also means that some of our tests have to be revised for them.

But the really big thing is, with all the PFAS that are out there, the onus now seems to be shifting on to the manufacturer to know what is in their products beyond just the big ones of PFOS and PFOA. I think that is where we’re going in terms of the testing market. It’s not just testing for individual compounds, but doing a total PFAS analysis at a screening level and then, if a product is above a certain threshold, we do a more targeted, specific analysis.

Walter Brandl
Ask The Expert

Ask the Expert: Walter Brandl

Walter Brandl

As the Regional Director of Chemistry, North America, at Mérieux Nutrisciences, Walter Brandl oversees thousands of employees at the company’s state-of-the-art laboratories throughout the U.S. Here, he discusses the experiences that prepared him for a career in food contamination detection, his greatest successes, and the evolution of third-party testing in food safety. 

How has your professional background prepared you for your role as the Regional Director of Chemistry for North America?

Brandl: Strangely enough I think my experience outside the food industry has prepared me for my role as Regional Director of Chemistry. My background in environmental chemistry has given me insight into many approaches for contaminant determination in foods while my experience in biotechnology analysis allowed me to learn a very structured approach to method development and validation.

Of all the projects you have been a part of, which do you believe have had the most profound impact on food quality and safety?

Brandl: Our work in some of the FDA survey studies on acrylamide, arsenic speciation, and other contaminants that were used to assess risk and help provide a body of knowledge for policy decisions has probably had the biggest impact on food quality and safety. 

As an expert in the field, where do you see third-party testing laboratories headed? What will be the biggest challenges and keys to success?

Brandl: I think that the scientists who previously saw themselves as having purely technical responsibilities are now being asked to become a bigger part of the process in terms of providing guidance and interpretation of results. We will be required to have a more in-depth understanding of our client’s processes and problems so as to take a more active role in solving their problems. Communication and a greater knowledge of multiple industries will be the wave of the future. 

What famous person past or present would you most like to have dinner with and why?

Brandl: Tough question, but I think I would choose one of the very successful sports coaches, someone like Bill Belichick of the New England Patriots or Sir Graham Henry of the New Zealand All Blacks. Probably Graham Henry due to the nature of rugby. The reason is that I see the challenge of blending technical knowledge with personalities and emotions in sport reflected in the passion that scientists have for their endeavors. I would love to get their take on how to maintain intensity without burnout, making everyone’s contribution absolutely essential, and motivating people to get better every day.

Contact our chemistry food experts today! 

PFAS

Phasing Out PFAS

By Food Safety Tech Staff
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PFAS

Efforts to regulate and remediate per- and polyfluoroalkyl substances (PFAS) are picking up a steam. Earlier this month, researchers from Northwestern University published a study verifying a low-cost process that breaks the chemical bonds of two major classes of PFAS compounds—perfluoroalkyl carboxylic acids (PFCAs) and perfluoroalkyl ether carboxylic acids (PFECAs)—leaving behind only benign end products.

Last week, the EPA proposed designating perfluorooctanoic acid (PFOA) and perfluorooctanesulfonic acid (PFOS), two of the most widely used PFAS, as hazardous substances. If finalized, the rule will trigger industry reporting of PFOA and PFOS releases and allow the agency to require cleanups and recover cleanup costs.

For the food and beverage industry, most current regulations involve food contact packaging, with states outpacing the FDA in implementing thresholds and working toward outright bans.

“Maine has a declaration requirement for PFAS in food packaging, and eight states are in motion to completely ban PFAS in food packaging products,” says Sally Powell Price, regulatory expert for food and beverage safety, MilliporeSigma.

California, Connecticut, Maine, Minnesota, New York, Vermont and Washington are among the states that have already passed legislation limiting the use of PFAS in food packaging. Outside the U.S., the Eurpean Commissions’ Restrictions Roadmap outlines a plan to outlaw the use of PFAS in packaging by 2030.

The good news for the food and beverage industry is that non-PFAS packaging alternatives are affordable. “The alternatives are fairly priced, so if manufacturers are converting from PFAS to non-PFAS materials, it may require changing some processes, but the price will not change very much,” says Yanqi Qu, food & beverage safety and quality technology specialist, MilliporeSigma.

The area that poses a greater challenge and requires more significant investment from the public and potentially industry groups lies in the testing of actual food commodities. This is also an area of increased regulatory scrutiny.

Regulating and Detecting PFAS in Food

In July, the FDA released the results of its Total Diet Study, which included outcomes of its retail seafood products PFAS testing. “This testing actually catalyzed a recall of clam products from China,” says Price. “The FDA tested foods imported from all regions for the study, so this is something that the FDA is monitoring. I can see this recent recall driving them to do more testing at the border for products coming in to the U.S., especially seafood.”

The state of Maine has dairy testing mandates already in place. “PFAS are bio-accumulators, so it’s not just fish. Cattle and other livestock could also be an issue,” says Price. “The testing program in Maine is a regulatory model that I would use to extrapolate and look at where our future could lie.”

One of the key challenges in detecting PFAS levels in food commodities lies in the variety of matrices to be tested and the huge numbers of PFAS currently in the environment. In December 2021, the FDA published its methodology for PFAS analysis in food and beverage, which focused on fruits, vegetables and beverage samples.

“They are using an extraction method. They used a solvent to extract materials from the surface of the food and beverage samples, and then analyzed them using a liquid chromatoghraphy and mass spectrometry (LC-MS) system,” says Qu. “This method was just posted last year, and the public is not satisfied with it. There are more than 600 different types of PFAS compounds, and for this method they only focused on 16 of them. The FDA is saying, we need more time to test for all 600.”

LC-MS used to test for PFAS in food and beverages is very similar to the PFAS testing in the environment. However, testing food products is more complex than testing water or soil. “Different foods have different interferences and complications, and it is extremely difficult to account for all of the potential interferences and or complications that might arise as you move from one matrix to another,” says Taylor Reynolds, marketing manager for environmental testing and industrial chemical manufacturing, MilliporeSigma. “The science is struggling to keep up. You get into issues where you might have overlapping peaks on your chromatogram, which makes it hard to distinguish the readings. Calibration standards are not all readily available. So, even if a lab wanted to test for 600 compounds, I’m not sure they could easily get their hands on 600 compounds as a reference standard to do their calibration groups.”

What Food Manufacturers Can Do

Price encourages food manufacturers to keep an eye on their state legislatures for proposed and upcoming regulations and be aware of known concerns specific to their areas. “The FDA looks to best fit for purpose,” she says. “So if there is a known concern, for example local data shows that you have PFAS infiltration in the ground water near your livestock or your crops, having a testing plan in place or a mitigation strategy is a good idea, where possible.”

Local FDA and EPA departments can often provide mitigation support as well as guidance to ensure you are aligned with local regulations.

In the coming years, we are likely to see not only more stringent regulations, but also a better understanding of the most hazardous PFAS compounds to help target mitigation and replacement strategies. This data combined with continued efforts to neutralize PFAS, as seen in the Northwestern study, could signal a promising future.

“Our work addressed one of the largest classes of PFAS, including many we are most concerned about,” said William Dichtel, Robert L. Letsinger Professor of Chemistry in Northwestern’s Weinberg College of Arts and Sciences, and lead author of the Northwesten study. “There are other classes that don’t have the same Achilles’ heel, but each one will have its own weakness. If we can identify it, then we know how to activate it to destroy it.”

“PFAS compounds have been so incredibly useful, yet weaning ourselves off of them is not going to be terribly difficult,” says Reynolds. “As long as organizations keep their heads up and are paying at least a marginal amount of attention, it shouldn’t be a terribly difficult to transition away from them, particularly on the packaging side of things. I personally am optimistic about the ultimate resolution of this issue, because people are taking it seriously and the science is showing that we can find solutions.”

 

Image: PFAS Molecule, courtesy of NIST

magnifying glass

Pathogens, Contamination and Technology in Food Safety Key Themes of 2022 Thus Far

By Food Safety Tech Staff
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magnifying glass

Nearly halfway into the year, the following are the most-read articles of 2022:

6. Four Testing and Detection Trends for 2022

Four Testing and Detection Trends for 2022


5. Packaging Automation Can Be an Essential Tool for Food Manufacturers

Packaging Automation Can Be an Essential Tool for Food Manufacturers


4. 8 Reasons Sustainability is Critical in Food and Beverage Manufacturing

8 Reasons Sustainability is Critical in Food and Beverage Manufacturing


3. The Costs Of Food Safety: Correction vs. Prevention

The Costs Of Food Safety: Correction vs. Prevention


2. FDA Continues Investigation of Listeria Outbreak in Packaged Salad

FDA Continues Investigation of Listeria Outbreak in Packaged Salad

1. Coca Cola Recalls Minute Maid, Coca Cola and Sprite Drinks Due to Foreign Matter Contamination

Coca Cola Recalls Minute Maid, Coca Cola and Sprite Drinks Due to Foreign Matter Contamination

Skippy peanut butter

Metal Fragments Prompt Recall of More Than 160,000 Pounds of Skippy Peanut Butter

By Food Safety Tech Staff
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Skippy peanut butter

Skippy Foods, LLC issued a voluntary recall of certain peanut butter jars due to concerns of metal fragment contamination, which may have originated from a piece of manufacturing equipment. The recall affects 9,353 cases (161,692 pounds) of product: Skippy Reduced Fat Creamy Peanut Butter (40 oz ), Skippy Reduced Fat Chunky Peanut Butter (16.3 oz), and Skippy Creamy Peanut Butter Blended with Plant Protein (14 oz). The products have various “Best If Used By” Dates ranging from May 4–10, 2023.

The issue was uncovered by the manufacturing facility’s internal detection systems. No other sizes or varieties of Skippy brand peanut butter or spreads are affected by this recall. In addition, no consumer complaints have been associated with this recall thus far.

Susanne Kuehne, Decernis
Food Fraud Quick Bites

The (Automated) Nose Knows

By Susanne Kuehne
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Susanne Kuehne, Decernis
Whisky fraud detection
Find records of fraud such as those discussed in this column and more in the Food Fraud Database, owned and operated by Decernis, a Food Safety Tech advertiser. Image credit: Susanne Kuehne

Rare and old whisky can be a significant investment, except for when they are fraudulent. One report found that about one-third of rare whisky (and wine) may be fake, leading to $1.5 billion in losses in Europe alone. A handheld device is now able to detect fraudulent products rapidly. The analysis method involves electrodes that analyze characteristic groups of molecules that can be found in the real product. The device then checks the results against real whisky samples from a database.

Resource
Miller, K. (September 16, 2021). “This Handheld Device Can Detect Fake Whisky In Minutes”. InsideHook. Yahoo.com

Susanne Kuehne, Decernis
Food Fraud Quick Bites

Crisp, But Not Clean

By Susanne Kuehne
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Susanne Kuehne, Decernis
Palm Oil, Food Fraud
Find records of fraud such as those discussed in this column and more in the Food Fraud Database, owned and operated by Decernis, a Food Safety Tech advertiser. Image credit: Susanne Kuehne

An especially perfidious type of edible oil fraud is the dissolution of inedible plastic material, such as polypropylene or polyethylene packaging material, in hot cooking oil during the frying process. This is supposed to prolong the shelf life and the crispness of deep-fried snack food, not surprisingly with serious health implications. Attenuated total reflectance fourier-transform infrared spectroscopy (ATR-FTIR) in combination with principal component analysis (PCA) provides a straightforward method to analyze samples directly with minimal preparation, to detect polymers in palm cooking oil, as done in this study.

Resource

  1. Ismail, D. et al. (2021). “Classification Model for Detection and Discrimination of inedible Plastic adulterated Palm Cooking Oil using ATR-FTIR Spectroscopy combined with Principal Component Analysis”. Vol 25 No 3. Malaysian Journal of Analytical Sciences (MJAS).
Allergens

Key Trends Reinforce Food Allergen Testing Market Across North America

By Saloni Walimbe
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Allergens

The food allergen testing industry has garnered considerable traction across North America, especially due to the high volume of processed food and beverages consumed daily. Allergens are becoming a significant cause for concern in the present food processing industry worldwide. Food allergies, which refer to abnormal reactions or hypersensitivity produced by the body’s immune system, are considered a major food safety challenge in recent years and are placing an immense burden on both personal and public health.

In 2019, the most common reason behind recalls issued by the USDA FSIS and the FDA was undeclared allergens. In light of this growing pressure, food producers are taking various steps to ensure complete transparency regarding the presence of allergenic ingredients, as well as to mitigate risk from, or possibly even prevent contact with, unintended allergens. One of these steps is food allergen testing.

Allergen detection tests are a key aspect of allergen management systems in food processing plants and are executed at nearly every step of the process. These tests can be carried out on work surfaces, as well as the products, to detect any cross contamination or allergen presence, and to test the effectiveness of a food processing unit’s cleaning measures.
There has been a surge in awareness among consumers about food allergies and tackling the risk of illnesses that may arise from consuming any ingredient. One of the key reasons for a higher awareness is efforts to educate the public. In Canada, for example, May has been designated “Food Allergy Awareness Month”. It is estimated that more than 3 million people in Canada are affected by food allergies.

The size of the global food allergen testing market is anticipated to gain significant momentum over the coming years, with consistent expansion of the dairy, processed food and confectionary segments.

Understanding the Prevailing Trends in Food Allergen Testing Industry

Food allergies risen nearly 50% in the last 10 years, with a staggering 700% increase observed in hospitalizations due to anaphylaxis. Studies also suggest that food allergies are a growing health concern, with more than 250 million people worldwide estimated to be affected.

Although more than 170 foods have been identified as causing food allergies in sensitive consumers, the USDA and the FDA have identified eight major allergenic foods, based on the 2004 FALCPA (the Food Allergen Labeling and Consumer Protection Act). These include eggs, milk, shellfish, fish, peanuts, tree nuts, soybean, and wheat, which are responsible for 90% of allergic reactions caused due to food consumption. In April 2021, the FASTER (Food Allergy Safety, Treatment, Education, and Research) Act was signed into law, which categorized sesame as the ninth major food allergen.

This ever-increasing prevalence of allergy-inducing foods has presented lucrative opportunities for the food allergen testing industry in recent years since food processing business operators are placing a strong emphasis on ensuring transparency in their products’ ingredient lists. By testing for allergens in food products, organizations can accurately mention each ingredient, and thereby allow people with specific food allergies to avoid consuming them.

Several allergen detection methods are used in the food processing industry, including mass spectrometry, DNA-based polymerase chain reaction (PCR) as well as ELISA (enzyme-linked immunosorbent assay), to name a few. The FDA, for instance, created a food allergen detection assay, called xMAP, designed to simultaneously identify 16 allergens, including sesame, within a single analysis, along with the ability to expand for the targeting of additional food allergens. Such industry advancements are improving the monitoring process for undeclared allergen presence in the food supply chain and enabling timely intervention upon detection.

Furthermore, initiatives, such as the Voluntary Incidental Trace Allergen Labelling (VITAL), created and managed by the Allergen Bureau, are also shedding light on the importance of allergen testing in food production. The VITAL program is designed to support allergen management with the help of a scientific process for risk assessment, in order to comply with food safety systems like the HACCP (Hazard Analysis and Critical Control Point), with allergen analysis playing a key role in its application.

ELISA Gains Prominence as Ideal Tool for Food Allergen Testing

In life sciences, the detection and quantification of various antibodies or antigens in a cost-effective and timely manner is of utmost importance. Detection of select protein expression on a cell surface, identification of immune responses in individuals, or execution of quality control testing—all these assessments require a dedicated tool.

ELISA is one such tool proving to be instrumental for both diagnostics as well as research). Described as an immunological assay, ELISA is used commonly for the measurement of antibodies or antigens in biological samples, including glycoproteins or proteins.

While its utility continues to grow, ELISA-based testing has historically demonstrated excellent sensitivity in food allergen testing applications, in some cases down to ppm (parts per million). It has a distinct advantage over other allergen detection methods like PCR, owing to the ability to adapt to certain foods like milk and oils, where its counterparts tend to struggle. The FDA is one of the major promoters of ELISA for allergen testing in food production, involving the testing of food samples using two different ELISA kits, prior to confirming results.

Many major entities are also taking heed of the growing interest in the use of ELISA for food allergen diagnostics. A notable example of this is laboratory analyses test kits and systems supplier, Eurofins, which introduced its SENSISpec Soy Total protein ELISA kit in September 2020. The enzyme immunoassay, designed for quantitative identification of soy protein in swab and food samples, has been developed by Eurofins Immunolab to measure residues of processed protein in various food products, including instant meals, chocolate, baby food, ice cream, cereals, sausage, and cookies, among others.

In essence, food allergens continue to prevail as high-risk factors for the food production industry. Unlike other pathogens like bacteria, allergenic proteins are heat resistant and stable, and cannot easily be removed once present in the food supply chain. In this situation, diagnostic allergen testing, complete segregation of allergenic substances, and accurate food allergen labeling are emerging as the ideal courses of action for allergen management in the modern food production ecosystem, with advanced technologies like molecular-based food allergy diagnostics expected to take up a prominent role over the years ahead.

Salmonella

July 15 Virtual Event Targets Challenges and Best Practices in Salmonella Detection, Mitigation and Control

By Food Safety Tech Staff
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Salmonella

Next week, Food Safety Tech is hosting the second event in its Food Safety Hazards Series, “Salmonella Detection, Mitigation, Control & Regulation”.

The event begins at 11:45 am ET on Thursday, July 15.

Presentations are as follows:

  • Get with the Program: Modernization of Poultry Inspections in the United States; A panel discussion with Mitzi Baum, STOP Foodborne Illness;
    Sarah Sorscher, Center for Science in the Public Interest; Martin Weidman, DMV, Ph.D., Cornell University; and Bruce Stewart-Brown, Perdue Foods
  • Detect, Deter, Destroy! A Discussion on Salmonella Detection, Mitigation and Control, with Elise Forward, Forward Food Solutions; Dave Pirrung, DCP Consulting; additional speaker TBA
  • A Case Study on Salmonella, with Rob Mommsen, Sabra Dipping Company
  • Sponsored TechTalks will be provided by Will Eaton of Meritech, Patrick Casey of BestSanitizer, Adam Esser of Sterilex, and Asif Rahman of Weber Scientific.

Register now for the Food Safety Hazards Series: Salmonella Detection, Mitigation, Control & Regulation.

Olga Pawluczyk, P&P Optica
FST Soapbox

Assessing Detection Systems to Make Food Safer

By Olga Pawluczyk
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Olga Pawluczyk, P&P Optica

It is an exciting time to be in the food industry. Consumers are ever more aware of what they are eating and more demanding of quality. And the vital need to reduce global food waste is transforming how we produce and consume food. This is driving innovation all the way along the supply chain, from gate to plate.

One of the biggest areas of opportunity for the industry to increase automation and improve food safety is in the processing plant. The challenges processors have faced in the last 12 months have accelerated the focus on optimizing resources and the drive for more adoption of new technology.

Foreign material contamination is a growing issue in the meat industry and new types of detection systems are emerging to help address this challenge. As Casey Gallimore, director of regulatory and scientific affairs at the North American Meat Institute, highlighted in a recent webinar, 2019 was a record year for the number of recalls related to foreign object contamination, which totaled 27% of all FSIS recalls in that year.

“There are a number of potential reasons why recalls due to foreign object contamination have increased over the years: Greater regulatory focus, more discerning consumers, [and] more automation in plants. But one important reason for this trend is that we have a lot of new technology to help detect more, [but] we are not necessarily using it to its full potential,” said Gallimore. “As an industry, we have a strong track record of working together to provide industry-wide solutions to industry-wide problems. And I believe that education is key to understanding how different detection systems—often used together—can increase the safety and quality of our food.”

Types of Detection Systems

Processors use many different detection systems to find foreign materials in their products. Equipment such as x-rays and metal detectors, which have been used for many years, are not effective against many of today’s contaminants: Plastics, rubber, cardboard and glass. And even the most well trained inspectors are affected by fatigue, distraction, discomfort and many other factors. A multi-hurdle approach is imperative, and new technologies like vision systems need to be considered.

Vision systems, such as cameras, multi-spectral, and hyperspectral imaging systems can find objects, such as low-density plastics, that may have been missed by other detection methods. Yet, depending on the system, their performance and capabilities can vary widely.

Camera-based systems are the most similar to the human eye. These systems are good for distinguishing objects of varying size and shape, albeit in two-dimensions rather than three. But they become less effective in situations with low contrast between the background and the object being detected. Clear plastics are a good example of this.

Multi-spectral systems are able to see more colors, including wavelengths outside of the visible spectrum. However, multispectral systems are set up to use only specific wavelengths, which are selected based on the materials that the system is expected to detect. That means that multispectral systems can identify some chemical as well as visual properties of materials, based on those specific wavelengths. It also means that other materials, which the system has not been designed to find, will likely not be detected by a multispectral system.

Another relatively new type of vision system uses hyperspectral imaging. These systems use chemistry to detect differences in the materials being inspected and therefore recognize a broad range of different contaminants. They are especially good at seeing objects that cameras or human inspectors may miss and at identifying the specific contaminant that’s been detected. The same system can assess quality metrics such as composition and identify product flaws such as woody breast in chicken. Hyperspectral systems also gather tremendous amounts of chemistry data about the products they are monitoring and can use artificial intelligence and machine learning to get a more holistic picture of what is happening in the plant over time, and how to prevent future contamination issues. This might include identifying issues with a specific supplier, training or other process challenges on one line (or in one shift), or machinery in the plant that is causing ongoing contamination problems.

Many processors are considering implementing new inspection systems, and are struggling to understand how to compare the expected performance of different systems. One relatively simple methodology that can be used to evaluate system performance is, despite its simplicity, called a “Confusion Matrix”.

The Confusion Matrix

A confusion matrix is often used in machine learning. It compares the expected outcome of an event with the actual outcome in order to understand the reliability of a test.

Figure 1 shows four possible outcomes for any kind of test.

Actual (True Condition)

Predicted

(Measured Outcome)

Positive (P) Negative (N)
Positive Detection True Positives (TP) False Positives (FP)
Negative Detection False Negatives (FN) True Negatives (TN)
P = TP + FN N = FP + TN
Figure 1. Confusion Matrix

But what does a confusion matrix tell us, and how can it help us assess a detection system?

The matrix shows us that a detection system may incorrectly register a positive or negative detection event—known as a ‘False Positive’ or ‘False Negative’.

As an example, say we are testing for a disease such as COVID-19. We want to know how often our system will give us a True Positive (detecting COVID when it *IS* present) versus a False Positive (detecting COVID when it *IS NOT* present).

Let’s apply this to processing. If you are using an x-ray to detect foreign objects, a small piece of plastic or wood would pass through unnoticed. This is a False Negative. By contrast, a system that uses hyperspectral imaging would easily identify that same piece of plastic or wood, because it has a different chemical signature from the product you’re processing. This is a True Positive.

A high rate of false negatives—failing to identify existing foreign materials—can mean contaminated product ends up in the hands of consumers.

The other side of the coin is false positives, meaning that the detector believes foreign material to be present when in fact it is not. A high rate of False Positives can lead to significant and unnecessary product wastage, or in time lost investigating an incident that didn’t actually occur (see Figure 2).

True Positives and False Positives
Figure 2. Balance of True Positives and False Positives

The secret to a good detection system lies in carefully balancing the rates of true positives and false positives by adjusting the sensitivity of a system.

This is where testing comes in. By adjusting a system and testing under different conditions, and then plotting these outcomes on the confusion matrix, you get an accurate picture of the system’s performance.

Effectiveness of a Detector

Detection is not just the act of seeing. It is the act of making a decision based on what you have seen, by understanding whether something of importance has occurred. Many factors influence the effectiveness of any detection system.

Resolution. This is the smallest size of object that can possibly be detected. For example, when you look at a photograph, the resolution affects how closely you can zoom in on an image before it becomes blurry.

Signal to noise ratio. This measures the electronic “noise” of the detector and compares it with the “background noise” that may interfere with the signals received by the detector. Too much background noise makes it harder to identify a foreign object.

Speed of acquisition. This measures how fast the detector can process the signals it receives. Motion limits what you can see. As line speeds increase, this impacts what detectors are able to pick up.

Material being detected. The type of material being detected and its properties will have a significant impact on the likelihood of detection. As previously mentioned, for example, x-rays are unlikely to detect low-density materials such as cardboard, resulting in a high number of False Negatives.

Presentation or location of material being detected. Materials that are underneath another object, that are presented on an angle, are too similar to the product being inspected, or are partially obstructed may be more difficult for some detectors to find. This also presents a risk of False Negatives.

Complexity of the product under inspection. Product composition and appearance vary. For example, just like the human eye, finding a small object on a uniformly illuminated and uniform color background like a white kitchen floor is much easier than finding the same small object on a complex background like industrial carpet. Coarsely ground meat might be more difficult to detect than uniform back fat layers, for example.

Environment. Conditions such as temperature and humidity will have a significant effect on detection.

Detection Curves

To understand system performance even better, we can use a detection curve. This plots out the likelihood of detection against different variables (e.g., object size) and allows us to objectively compare how these different factors impact the performance of each system.

Figure 3 shows how this looks when plotted as a curve, with object size on the x-axis (horizontal) and the probability of detection (a True Positive from the Confusion Matrix) on the y-axis (vertical). It shows three examples of possible detection curves, depending on the detector being used.

Detection curves
Figure 3. Examples of detection curves for different detectors. Probability of detection of an object increases as the size of the object increases.

A detection curve tells you both the smallest and largest object that a detector will find and the probability that it will be found.

In the example presented by Figure 3, Detector 3 can see essentially 100% of large and very large objects, as can Detector 2. But Detector 3 is also more likely than the other two systems in the example to see microscopic objects. Based on this detection curve it would likely be the best option if the goal were to detect as many foreign objects as possible, of all sizes.

Of course, the performance of a detector is determined by multiple measures, not just size,

Detection capability can be improved for most detection systems, but typically comes at a significant cost: Increasing sensitivity will increase the number of false positives, resulting in increased product rejection. This is why looking at the detection curve together with the false-positive/false-negative rates for any detection system gives us a clear picture of its performance and is invaluable for food processing plants when selecting a system.

Using the confusion matrix and a detection curve, processors can compare different detection systems on an apples-to-apples basis. They can easily see whether a system can identify small, tiny or microscopic objects and, crucially, how often it will identify them.

Every detection method—X -ray, metal detection, vision systems, manual inspection—presents a trade-off between actual (correct) detection, rejection of good product (false positive) and missed detections (false negative). This simple way to compare differences means processors can make the right decision for the specific needs of their plant, based on easily gathered information. For all of us data geeks out there, that sounds like the Holy Grail.