Tag Archives: Testing

Susanne Kuehne, Decernis
Food Fraud Quick Bites

Separating the Wheat From the Chaff

By Susanne Kuehne
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Susanne Kuehne, Decernis
Food fraud, Argentina, durim wheat
Find records of fraud such as those discussed in this column and more in the Food Fraud Database.
Image credit: Susanne Kuehne.

Pasta is widely consumed around the world, and prices have increased because people have been stockpiling it during the COVID-19 pandemic. Durum wheat, the basic wheat for pasta, is the second most cultivated wheat around the world after common bread wheat, claiming 15–30% higher prices, and therefore an attractive target for food fraud. Out of 150 Argentinian pasta samples that were analyzed with a new method based on Fourier transform infrared spectroscopy (FTIR), in combination with Partial-Least Squares Discriminant Analysis (PLS-DA) and Linear Discriminant Analysis (LDA), 112 were found to be altered with common wheat. Argentinian labeling law requires durum wheat pasta to be based on 100% durum wheat.

Resource

  1. De Girolamo, A., et.al. (June 2020). “Detection of durum wheat pasta adulteration with common wheat by infrared spectroscopy and chemometrics: A case study”  LWT. Vol. 127. Elsevier.
Susanne Kuehne, Decernis
Food Fraud Quick Bites

The Straw that Broke the Camel’s Back

By Susanne Kuehne
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Susanne Kuehne, Decernis
Camel, cow, food fraud
Find records of fraud such as those discussed in this column and more in the Food Fraud Database. Image credit: Susanne Kuehne

Due to its health benefits, camel meat is gaining in popularity for consumers but unfortunately also for fraudsters for economic gain. Polymerase chain reaction (PCR) technologies allow quick and accurate detection of specific meat types, including processed and cooked meats. This newly developed PCR lateral flow immunology method found adulteration of camel meat with beef in 10% of the 20 samples that were investigated in this Chinese study.

Resource

  1. Zhao, L., et. al. (July 30, 2020). “Identification of camel species in food products by a polymerase chain reaction-lateral flow immunoassay”. Food Chemistry. Science Direct. Volume 319.
Susanne Kuehne, Decernis
Food Fraud Quick Bites

Marzipan Or Persipan, That’s the Question

By Susanne Kuehne
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Susanne Kuehne, Decernis
Food fraud, almond tree
Find records of fraud such as those discussed in this column and more in the Food Fraud Database. Image credit: Susanne Kuehne

Both Prunus species produce similar flavor and sensory profiles, but have significantly different costs—the 50% cheaper apricot kernels are sometimes used as an adulterant, replacing almonds in products such as marzipan, almond oil or almond powder. A polymerase chain reaction (PCR) method shows that the DNA barcode of almond shows significant differences from other Prunus species and can therefore be used to detect adulteration of almond products.

Resource

  1. Uncu, A.O. (March 2, 2020). “A trnH-psbA barcode genotyping assay for the detection of common apricot (Prunus armeniaca L.) adulteration in almond (Prunus dulcis Mill.)” Retrieved from Taylor & Francis Online.
Alert

Meat Shortage Threat, Facility Employees Can Still Work After Potential COVID-19 Exposure

By Maria Fontanazza
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Alert

–UPDATE April 29, 2020— Yesterday President Trump signed an executive order to keep meat and poultry processing facilities operational during the coronavirus national emergency. U.S. Secretary of Agriculture Sonny Perdue said the following in a USDA statement, “Maintaining the health and safety of these heroic employees in order to ensure that these critical facilities can continue operating is paramount. I also want to thank the companies who are doing their best to keep their workforce safe as well as keeping our food supply sustained. USDA will continue to work with its partners across the federal government to ensure employee safety to maintain this essential industry.”

–END UPDATE–

As critical infrastructure workers, employees at meat and poultry processing facilities have stayed on the job during the coronavirus crisis. Hundreds have fallen ill and many have died as a result; at least 100 USDA inspectors have tested positive for COVID-19 and at least one inspector has died, according to reports. Production facilities across the country have shut down over the past month, and the threat of a meat shortage is very close to becoming a reality, warns Tyson Foods Chairman John Tyson. “In small communities around the country where we employ over 100,000 hard-working men and women, we’re being forced to shutter our doors. This means one thing—the food supply chain is vulnerable. As pork, beef and chicken plants are being forced to close, even for short periods of time, millions of pounds of meat will disappear from the supply chain,” Tyson stated in a company blog. “As a result, there will be limited supply of our products available in grocery stores until we are able to reopen our facilities that are currently closed.”

Hog and cattle producers are altering rations to slow the growth of livestock. In Iowa, the National Guard was activated to conduct testing and contact tracing of plant workers from Tyson Foods and National Beef Packing Company.

Meat production is on a 25% decline and by the end of this week, America could be entering a meat shortage, according to Dennis Smith, an Archer Financial Services commodity broker and livestock analyst.

Access the COVID-19 Resource CenterProtecting Essential Employees

“To ensure continuity of operations of essential functions, CDC advises that critical infrastructure workers may be permitted to continue work following potential exposure to COVID-19, provided they remain asymptomatic and additional precautions are implemented to protect them and the community,” the CDC’s Critical Infrastructure Guidance states. The agency also notes that screening workers for COVID-19 symptoms is “an optional strategy”.

Meat processing workers are not exposed to COVID-19 through product handling; they can be exposed via close contact with other employees in a facility. The CDC and OSHA have released interim guidance for meat and poultry processing workers and employers that details how communal work environments should be laid out and how employers should be promoting social distancing. Engineering controls include the following:

  • Reconfiguration of workstations to allow employees to be six feet apart, if possible
  • Establishing physical barriers (i.e., plexiglass or strip curtains) to separate workers
  • Working with an HVAC engineer to establish proper ventilation that limits potential exposure to coronavirus; removal of any pedestal or personal fans
  • Setting up handwashing stations or hand sanitizer (60% alcohol) stations
  • Reconfiguring break rooms and other communal areas to promote social distancing

The CDC also recommends that workers wear cloth face coverings that fit over the mouth and nose.

For workers who have experienced COVID-19 symptoms and have self-isolated at home, the CDC advises they do not return to work until they meet specific criteria.

Read the CDC and OSHA interim guidance.

Raj Rajagopal, 3M Food Safety
In the Food Lab

Pathogen Detection Guidance in 2020

By Raj Rajagopal
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Raj Rajagopal, 3M Food Safety

Food production managers have a critical role in ensuring that the products they make are safe and uncontaminated with dangerous pathogens. Health and wellness are in sharp focus for consumers in every aspect of their lives right now, and food safety is no exception. As food safety becomes a continually greater focus for consumers and regulators, the technologies used to monitor for and detect pathogens in a production plant have become more advanced.

It’s no secret that pathogen testing is performed for numerous reasons: To confirm the adequacy of processing control and to ensure foods and beverages have been properly stored or cooked, to name some. Accomplishing these objectives can be very different, and depending on their situations, processors rely on different tools to provide varying degrees of testing simplicity, speed, cost, efficiency and accuracy. It’s common today to leverage multiple pathogen diagnostics, ranging from traditional culture-based methods to molecular technologies.

And unfortunately, pathogen detection is more than just subjecting finished products to examination. It’s become increasingly clear to the industry that the environment in which food is processed can cross-contaminate products, requiring food manufacturers to be ever-vigilant in cleaning, sanitizing, sampling and testing their sites.

For these reasons and others, it’s important to have an understanding and appreciation for the newer tests and techniques used in the fight against deadly pathogens, and where and how they might be fit for purpose throughout the operation. This article sheds light on the key features of one fast-growing DNA-based technology that detects pathogens and explains how culture methods for index and indicator organisms continue to play crucial roles in executing broad-based pathogen management programs.

LAMP’s Emergence in Molecular Pathogen Detection

Molecular pathogen detection has been a staple technology for food producers since the adoption of polymerase chain reaction (PCR) tests decades ago. However, the USDA FSIS revised its Microbiology Laboratory Guidebook, the official guide to the preferred methods the agency uses when testing samples collected from audits and inspections, last year to include new technologies that utilize loop-mediated isothermal amplification (LAMP) methods for Salmonella and Listeria detection.

LAMP methods differ from traditional PCR-based testing methods in four noteworthy ways.

First, LAMP eliminates the need for thermal cycling. Fundamentally, PCR tests require thermocyclers with the ability to alter the temperature of a sample to facilitate the PCR. The thermocyclers used for real-time PCR tests that allow detection in closed tubes can be expensive and include multiple moving parts that require regular maintenance and calibration. For every food, beverage or environmental surface sample tested, PCR systems will undergo multiple cycles of heating up to 95oC to break open DNA strands and cooling down to 60oC to extend the new DNA chain in every cycle. All of these temperature variations generally require more run time and the enzyme, Taq polymerase, used in PCR can be subjected to interferences from other inhibiting substances that are native to a sample and co-extracted with the DNA.

LAMP amplifies DNA isothermally at a steady and stable temperature range—right around 60oC. The Bst polymerase allows continuous amplification and better tolerates the sample matrix inhibitors known to trip up PCR. The detection schemes used for LAMP detection frees LAMP’s instrumentation from the constraints of numerous moving pieces.

Secondly, it doubles the number of DNA primers. Traditional PCR tests recognize two separate regions of the target genetic material. They rely on two primers to anneal to the subject’s separated DNA strands and copy and amplify that target DNA.

By contrast, LAMP technology uses four to six primers, which can recognize six to eight distinct regions from the sample’s DNA. These primers and polymerase used not only cause the DNA strand to displace, they actually loop the end of the strands together before initiating amplification cycling. This unique looped structure both accelerates the reaction and increases test result sensitivity by allowing for an exponential accumulation of target DNA.

Third of all, it removes steps from the workflow. Before any genetic amplification can happen, technicians must enrich their samples to deliberately grow microorganisms to detectable levels. Technicians using PCR tests have to pre-dispense lysis buffers or reagent mixes and take other careful actions to extract and purify their DNA samples.

Commercialized LAMP assay kits, on the other hand, offer more of a ready-to-use approach as they offer ready to use lysis buffer and simplified workflow to prepare DNA samples. By only requiring two transfer steps, it can significantly reduces the risk of false negatives caused by erroneous laboratory preparation.

Finally, it simplifies multiple test protocols into one. Food safety lab professionals using PCR technology have historically been required to perform different test protocols for each individual pathogen, whether that be Salmonella, Listeria, E. coli O157:H7 or other. Not surprisingly, this can increase the chances of error. Oftentimes, labs are resource-challenged and pressure-packed environments. Having to keep multiple testing steps straight all of the time has proven to be a recipe for trouble.

LAMP brings the benefit of a single assay protocol for testing all pathogens, enabling technicians to use the same protocol for all pathogen tests. This streamlined workflow involving minimal steps simplifies the process and reduces risk of human-caused error.

Index and Indicator Testing

LAMP technology has streamlined and advanced pathogen detection, but it’s impractical and unfeasible for producers to molecularly test every single product they produce and every nook and cranny in their production environments. Here is where an increasing number of companies are utilizing index and indicator tests as part of more comprehensive pathogen environmental programs. Rather than testing for specific pathogenic organisms, these tools give a microbiological warning sign that conditions may be breeding undesirable food safety or quality outcomes.

Index tests are culture-based tests that detect microorganisms whose presence (or detection above a threshold) suggest an increased risk for the presence of an ecologically similar pathogen. Listeria spp. Is the best-known index organism, as its presence can also mark the presence of deadly pathogen Listeria monocytogenes. However, there is considerable skepticism among many in the research community if there are any organisms outside of Listeria spp. that can be given this classification.

Indicator tests, on the other hand, detect the presence of organisms reflecting the general microbiological condition of a food or the environment. The presence of indicator organisms can not provide any information on the potential presence or absence of a specific pathogen or an assessment of potential public health risk, but their levels above acceptable limits can indicate insufficient cleaning and sanitation or operating conditions.

Should indicator test results exceed the established control limits, facilities are expected to take appropriate corrective action and to document the actions taken and results obtained. Utilizing cost-effective, fast indicator tests as benchmark to catch and identify problem areas can suggest that more precise, molecular methods need to be used to verify that the products are uncontaminated.

Process Matters

As discussed, technology plays a large role in pathogen detection, and advances like LAMP molecular detection methods combined with strategic use of index and indicator tests can provide food producers with powerful tools to safeguard their consumers from foodborne illnesses. However, whether a producer is testing environmental samples, ingredients or finished product, a test is only as useful as the comprehensive pathogen management plan around it.

The entire food industry is striving to meet the highest safety standards and the best course of action is to adopt a solution that combines the best technologies available with best practices in terms of processes as well –from sample collection and preparation to monitoring and detection.

Susanne Kuehne, Decernis
Food Fraud Quick Bites

Finding the Root Cause for Starch Fraud

By Susanne Kuehne
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Susanne Kuehne, Decernis
Food fraud, cassava starch
Find records of fraud such as those discussed in this column and more in the Food Fraud Database.
Image credit: Susanne Kuehne

Due to its lower cost, cassava starch is a common adulterant in higher priced starches, such as for potato and wheat. Tests with droplet digital polymerase chain reaction ddPCR in China uncovered that over 30% of sweet potato starch samples, 25% of cornstarch samples and 40% of potato starch samples were adulterated with cassava starch. Besides the economic impact, this kind of fraud also poses a risk to consumers allergic to cassava.

Resource

  1. Chen, J., et. al. (February 26, 2020). “Identification and quantification of cassava starch adulteration in different food starches by droplet digital PCR”. PLOS One.
Crop spraying, Ellutia

From Farm to Fork: The Importance of Nitrosamine Testing in Food Safety

By Andrew James
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Crop spraying, Ellutia

N-nitroso compounds (NOCs), or nitrosamines, have once again made headline news as their occurrence in some pharmaceuticals has led to high profile product recalls in the United States.1 Nitrosamines can be carcinogenic and genotoxic and, in the food industry, can compromise a food product’s quality and safety. One nitrosamine in particular, N-nitrosodimethylamine (NDMA), is a highly potent carcinogen, traces of which are commonly detected in foods and may be used as an indicator compound for the presence of nitrosamines.2

NOCs can potentially make their way into the food chain in a number of ways, including (but not limited to): Via the crop protection products used to maximize agricultural yields; via the sodium and/or potassium salt added to preserve certain meats from bacterial contamination; as a result of the direct-fire drying process in certain foods; and via consumption of nitrates in the diet (present in many vegetables due to natural mineral deposits in the soil), which react with bacteria and acids in the stomach to form nitrosamines.3

The crop protection and food manufacturing industries are focused on ensuring that levels of nitrosamines present in foods are minimal and safe. Detection technology for quantitating the amount of nitrosamines (ppm levels) in a sample had not advanced in nearly 40 years—until recently. Now, a thermal energy analyzer (TEA) —a sensitive and specific detector—is being relied on to provide fast and sensitive analysis for players throughout the food supply chain.

Regulatory Landscape

Both NDMA and the nitrosamine N-nitrososodiethylamine (NDEA) have been classified by national and international regulatory authorities as ‘probable human carcinogens’.3 NDMA in particular is by far the most commonly encountered member of this group of compounds.7

In the United States there are limits for NDMA or total nitrosamines in bacon, barley malt, ham and malt beverages, yet there are currently no regulatory limits for N-nitroso compounds (NOC) in foods in the EU.7

Developers of crop protection products are required to verify the absence of nitrosamines or quantify the amount at ppm levels to ensure they are within the accepted guidelines.

Crop Protection

The presence of nitrosamines must be traced and risk-managed along the food’s journey from farm to fork. The issue affects testing from the very beginning – particularly at the crop protection stage, which is one of the most highly regulated industries in the world. Without crop protection, food and drink expenditures could increase by up to £70 million per year and 40% of the world’s food would not exist.7

Development of a new crop protection product (herbicide, fungicide, insecticide or seed treatment) involves several steps: Discovery and formulation of the product, trials and field development, toxicology, environmental impacts and final registration. New product registration requires demonstration of safety for all aspects of the environment, the workers, the crops that are being protected and the food that is consumed. This involves comprehensive risk assessments being carried out, based on data from numerous safety studies and an understanding of Good Agricultural Practice (GAP).

One global producer of agrochemicals uses a custom version of the TEA to verify the absence of nitrosamines or quantitate the amount of nitrosamines (ppm levels) in its active ingredients. The LC-TEA enables high selectivity for nitro, nitroso and nitrogen (when operating in nitrogen mode), which allows only the compounds of interest to be seen. Additionally, it provides very high sensitivity (<2pg N/sec Signal to Noise 3:1), meaning it is able to detect compounds of interest at extremely low levels. To gain this high sensitivity and specificity, it relies on a selective thermal cleavage of N-NO bond and detection of the liberated NO radical by the chemiluminescent signal generated by its reaction with ozone.

The customized system also uses a different interface with a furnace, rather than the standard pyrolyser, to allow for the additional energy required and larger diameter tubing for working with a liquid sample rather than gas.

The system allows a company to run five to six times more samples with increased automation. As a direct result, significant productivity gains, reduced maintenance costs and more accurate results can be realized.

Food Analysis

Since nitrite was introduced in food preservation in the 1960s, its safety has been debated. The debate continues today, largely because of the benefits of nitrite in food products, particularly processed meats.6 In pork products, such as bacon and cured ham, nitrite is mostly present in the sodium and/or potassium salt added to preserve the meat from bacterial contamination. Although the meat curing process was designed to support preservation without refrigeration, a number of other benefits, such as enhancing color and taste, have since been recognized.

Analytical methods for the determination of N-nitrosamines in foods can differ between volatile and non-volatile compounds. Following extraction, volatile N-nitrosamines can be readily separated by GC using a capillary column and then detected by a TEA detector. The introduction of the TEA offered a new way to determine nitrosamine levels at a time when GC-MS could do so only with difficulty.

To identify and determine constituent amounts of NOCs in foods formed as a direct result of manufacturing and processing, the Food Standards Agency (FSA) approached Premier Analytical Services (PAS) to develop a screening method to identify and determine constituent amounts of NOCs in foods formed as a direct result of manufacturing and processing.

A rapid and selective apparent total nitrosamine content (ATNC) food screening method has been developed with a TEA. This has also been validated for the known dietary NOCs of concern. This method, however, is reliant on semi-selective chemical denitrosation reactions and can give false positives. The results can only be considered as a potential indicator rather than definitive proof of NOC presence.

In tests, approximately half (36 out of 63) samples returned a positive ATNC result. Further analysis of these samples by GC-MS/MS detected volatile nitrosamine contamination in two of 25 samples.

A key role of the TEA in this study was to validate the alternative analytical method of GC-MS/MS. After validation of the technique by TEA, GC-MS/MS has been proven to be highly sensitive and selective for this type of testing.

The Future of Nitrosamine Testing

Many countries have published data showing that toxicological risk from preformed NOCs was no longer considered an area for concern. Possible risks may come from the unintentional addition or contamination of foods with NOCs precursors such as nitrite and from endogenous formation of NOCs and more research is being done in this area.

Research and innovation are the foundations of a competitive food industry. Research in the plant protection industry is driven by farming and the food chain’s demand for greater efficiency and safer products. Because the amount of nitrosamines in food that results in health effects in humans is still unknown, there is scope for research into the chemical formation and transportation of nitrosamines, their occurrence and their impact on our health. Newer chromatographic techniques are only just being applied in this area and could greatly benefit the quantification of nitrosamines. It is essential that these new approaches to quality and validation are applied throughout the food chain.

References

  1. Christensen, J. (2020). More popular heartburn medications recalled due to impurity. CNN.
  2. Hamlet, C, Liang, L. (2017). An investigation to establish the types and levels of N-nitroso compounds (NOC) in UK consumed foods. Premier Analytical Services, 1-79.
  3. Woodcock, J. (2019). Statement alerting patients and health care professionals of NDMA found in samples of ranitidine. Center for Drug Evaluation and Research.
  4. Scanlan, RA. (1983). Formation and occurrence of nitrosamines in food. Cancer res, 43(5) 2435-2440.
  5.  Dowden, A. (2019). The truth about nitrates in your food. BBC Future.
  6.  Park, E. (2015). Distribution of Seven N-nitrosamines in Food. Toxicological research, 31(3) 279-288, doi: 10.5487/TR.2015.31.3.279.
  7.  Crews, C. (2019). The determination of N-nitrosamines in food. Quality Assurance and Safety of Crops & Foods, 1-11, doi: 10.1111/j.1757-837X.2010.00049.x
  8. (1989) Toxicological profile for n-Nitrosodimethylamine., Agency for Toxic substances and disease registry.
  9. Rickard, S. (2010). The value of crop protection, Crop Protection Association.
Food Labs Conference

Food Labs / Cannabis Labs 2020 Agenda Announced

By Food Safety Tech Staff
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Food Labs Conference

The agenda for the 2020 Food Labs / Cannabis Labs conference has been announced. The event, which will address regulatory, compliance and risk management issues that companies face in the area of testing and food laboratory management, is scheduled to take place on June 3–4 in Rockville, MD.

Some agenda highlights include a special morning session on June 3 that discusses the proposed FSMA rule on lab accreditation: “FSMA and the Impact on Laboratories and Laboratory Data Users” and “FSMA Proposed Rule on Laboratory Accreditation: What it says and what it should say” presented by Reinaldo Figueiredo of ANSI and Robin Stombler of Auburn Health Strategies, respectively. FDA has also been invited to speak on the proposed rule. Sessions will also cover the role of labs as it relates to pathogens, with presentations from Benjamin Katchman, Ph.D. (PathogenDx) about a novel DNA microarray assay used for detecting and speciating multiple Listeria species and Dave Evanson (Merieux Nutrisciences) on pathogen detection and control. The full agenda is listed on the Food Labs / Cannabis Labs website.

The early bird discount of $395 expires on March 31.

Innovative Publishing Company, Inc., the organizer of the conference, is fully taking into considerations the travel concerns related to the coronavirus. Should any
disruption that may prevent the production of this live event at its physical location in Rockville, MD due to COVID-19, all sessions will be converted to a virtual conference on the already planned dates. More information is available on the event website.

Michael Bartholomeusz, TruTag
In the Food Lab

Intelligent Imaging and the Future of Food Safety

By Michael Bartholomeusz, Ph.D.
1 Comment
Michael Bartholomeusz, TruTag

Traditional approaches to food safety no longer make the grade. It seems that stories of contaminated produce or foodborne illnesses dominate the headlines increasingly often. Some of the current safeguards set in place to protect consumers and ensure that companies are providing the freshest, safest food possible continue to fail across the world. Poorly regulated supply chains and food quality assurance breakdowns often sicken customers and result in recalls or lawsuits that cost money and damage reputations. The question is: What can be done to prevent these types of problems from occurring?

While outdated machinery and human vigilance continue to be the go-to solutions for these problems, cutting-edge intelligent imaging technology promises to eliminate the issues caused by old-fashioned processes that jeopardize consumer safety. This next generation of imaging will increase safety and quality by quickly and accurately detecting problems with food throughout the supply chain.

How Intelligent Imaging Works

In broad terms, intelligent imaging is hyperspectral imaging that uses cutting-edge hardware and software to help users establish better quality assurance markers. The hardware captures the image, and the software processes it to provide actionable data for users by combining the power of conventional spectroscopy with digital imaging.

Conventional machine vision systems generally lack the ability to effectively capture and relay details and nuances to users. Conversely, intelligent imaging technology utilizes superior capabilities in two major areas: Spectral and spatial resolution. Essentially, intelligent imaging systems employ a level of detail far beyond current industry-standard machinery. For example, an RGB camera can see only three colors: Red, green and blue. Hyperspectral imaging can detect between 300 and 600 real colors—that’s 100–200 times more colors than detected by standard RGB cameras.

Intelligent imaging can also be extended into the ultraviolet or infrared spectrum, providing additional details of the chemical and structural composition of food not observable in the visible spectrum. Hyperspectral imaging cameras do this by generating “data cubes.” These are pixels collected within an image that show subtle reflected color differences not observable by humans or conventional cameras. Once generated, these data cubes are classified, labeled and optimized using machine learning to better process information in the future.

Beyond spectral and spatial data, other rudimentary quality assurance systems pose their own distinct limitations. X-rays can be prohibitively expensive and are only focused on catching foreign objects. They are also difficult to calibrate and maintain. Metal detectors are more affordable, but generally only catch metals with strong magnetic fields like iron. Metals including copper and aluminum can slip through, as well as non-metal objects like plastics, wood and feces.

Finally, current quality assurance systems have a weakness that can change day-to-day: Human subjectivity. The people put in charge of monitoring in-line quality and food safety are indeed doing their best. However, the naked eye and human brain can be notoriously inconsistent. Perhaps a tired person at the end of a long shift misses a contaminant, or those working two separate shifts judge quality in slightly different ways, leading to divergent standards unbeknownst to both the food processor and the public.

Hyperspectral imaging can immediately provide tangible benefits for users, especially within the following quality assurance categories in the food supply chain:

Pathogen Detection

Pathogen detection is perhaps the biggest concern for both consumers and the food industry overall. Identifying and eliminating Salmonella, Listeria, and E.coli throughout the supply chain is a necessity. Obviously, failure to detect pathogens seriously compromises consumer safety. It also gravely damages the reputations of food brands while leading to recalls and lawsuits.

Current pathogen detection processes, including polymerase chain reaction (PCR), immunoassays and plating, involve complicated and costly sample preparation techniques that can take days to complete and create bottlenecks in the supply chain. These delays adversely impact operating cycles and increase inventory management costs. This is particularly significant for products with a short shelf life. Intelligent imaging technology provides a quick and accurate alternative, saving time and money while keeping customers healthy.

Characterizing Food Freshness

Consumers expect freshness, quality and consistency in their foods. As supply chains lengthen and become more complicated around the world, food spoilage has more opportunity to occur at any point throughout the production process, manifesting in reduced nutrient content and an overall loss of food freshness. Tainted meat products may also sicken consumers. All of these factors significantly affect market prices.

Sensory evaluation, chromatography and spectroscopy have all been used to assess food freshness. However, many spatial and spectral anomalies are missed by conventional tristimulus filter-based systems and each of these approaches has severe limitations from a reliability, cost or speed perspective. Additionally, none is capable of providing an economical inline measurement of freshness, and financial pressure to reduce costs can result in cut corners when these systems are in place. By harnessing meticulous data and providing real-time analysis, hyperspectral imaging mitigates or erases the above limiting factors by simultaneously evaluating color, moisture (dehydration) levels, fat content and protein levels, providing a reliable standardization of these measures.

Foreign Object Detection

The presence of plastics, metals, stones, allergens, glass, rubber, fecal matter, rodents, insect infestation and other foreign objects is a big quality assurance challenge for food processors. Failure to identify foreign objects can lead to major added costs including recalls, litigation and brand damage. As detailed above, automated options like X-rays and metal detectors can only identify certain foreign objects, leaving the rest to pass through untouched. Using superior spectral and spatial recognition capabilities, intelligent imaging technology can catch these objects and alert the appropriate employees or kickstart automated processes to fix the issue.

Mechanical Damage

Though it may not be put on the same level as pathogen detection, food freshness and foreign object detection, consumers put a premium on food uniformity, demanding high levels of consistency in everything from their apples to their zucchini. This can be especially difficult to ensure with agricultural products, where 10–40% of produce undergoes mechanical damage during processing. Increasingly complicated supply chains and progressively more automated production environments make delivering consistent quality more complicated than ever before.

Historically, machine vision systems and spectroscopy have been implemented to assist with damage detection, including bruising and cuts, in sorting facilities. However, these systems lack the spectral differentiation to effectively evaluate food and agricultural products in the stringent manner customers expect. Methods like spot spectroscopy require over-sampling to ensure that any detected aberrations are representative of the whole item. It’s a time-consuming process.

Intelligent imaging uses superior technology and machine learning to identify mechanical damage that’s not visible to humans or conventional machinery. For example, a potato may appear fine on the outside, but have extensive bruising beneath its skin. Hyperspectral imaging can find this bruising and decide whether the potato is too compromised to sell or within the parameters of acceptability.

Intelligent imaging can “see” what humans and older technology simply cannot. With the ability to be deployed at a number of locations within the food supply chain, it’s an adaptable technology with far-reaching applications. From drones measuring crop health in the field to inline or end-of-line positioning in processing facilities, there is the potential to take this beyond factory floors.

In the world of quality assurance, where a misdiagnosis can literally result in death, the additional spectral and spatial information provided by hyperspectral imaging can be utilized by food processors to provide important details regarding chemical and structural composition previously not discernible with rudimentary systems. When companies begin using intelligent imaging, it will yield important insights and add value as the food industry searches for reliable solutions to its most serious challenges. Intelligent imaging removes the subjectivity from food quality assurance, turning it into an objective endeavor.

Benjamin Katchman, PathogenDx
In the Food Lab

Revolutionary Rapid Testing for Listeria Monocytogenes and Salmonella

By Benjamin A. Katchman, Ph.D., Michael E. Hogan, Ph.D., Nathan Libbey, Patrick M. Bird
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Benjamin Katchman, PathogenDx

The Golden Age of Bacteriology: Discovering the Unknown in a Farm-to-Market Food Supply.

The last quarter of the 19th Century was both horrific and exciting. The world had just emerged from four decades of epidemic in cholera, typhoid fever and other enteric diseases for which no cause was known. Thus, the great scientific minds of Europe sought to find understanding. Robert Koch integrated Pasteur’s Germ Theory in 1861 with the high technology of the day: Mathematical optics and the first industrialized compound microscopes (Siebert, Leiss, 1877), heterocycle chemistry, high-purity solvents (i.e., formaldehyde), availability of engineered glass suitable as microscope slides and precision-molded parts such as tubes and plates in 1877, and industrialized agar production from seaweed in Japan in 1860. The enduring fruit of Koch’s technology integration tour de force is well known: Dye staining of bacteria for sub-micron microscopy, the invention of 13 cm x 1 cm culture tubes and the invention of the “Petri” dish coupled to agar-enriched culture media. Those technologies not only launched “The Golden Age of Bacteriology” but also guided the entire field of analytical microbiology for two lifetimes, becoming bedrock of 20th Century food safety regulation (the Federal Food, Drug and Cosmetic Act in 1938) and well into the 21st century with FSMA.

Learn more about technologies in food safety testing at the Food Labs / Cannabis Labs Conference | June 2–4, 2020 | Register now!Blockchain Microbiology: Managing the Known in an International Food Supply Chain.

If Koch were to reappear in 2020 and were presented with a manual of technical microbiology, he would have little difficulty recognizing the current practice of cell fixation, staining and microscopy, or the SOPs associated with fluid phase enrichment culture and agar plate culture on glass dishes (still named after his lab assistant). The point to be made is that the analytical plate culture technology developed by Koch was game changing then, in the “farm-to-market” supply chain in Koch’s hometown of Berlin. But today, plate culture still takes about 24 to 72 hours for broad class indicator identification and 48 to 96 hours for limited species level identification of common pathogens. In 1880, life was slow and that much time was needed to travel by train from Paris to Berlin. In 2020, that is the time needed to ship food to Berlin from any place on earth. While more rapid tests have been developed such as the ATP assay, they lack the speciation and analytical confidence necessary to provide actionable information to food safety professionals.

It can be argued that leading up to 2020, there has been an significant paradigm shift in the understanding of microbiology (genetics, systems based understanding of microbial function), which can now be coupled to new Third Industrial Age technologies, to make the 2020 international food supply chain safer.

We Are Not in 1880 Anymore: The Time has Come to Move Food Safety Testing into the 21st Century.

Each year, there are more than 48 million illnesses in the United States due to contaminated food.1 These illnesses place a heavy burden on consumers, food manufacturers, healthcare, and other ancillary parties, resulting in more than $75 billion in cost for the United States alone.2 This figure, while seemingly staggering, may increase in future years as reporting continues to increase. For Salmonella related illnesses alone, an estimated 97% of cases go unreported and Listeria monocytogenes is estimated to cause about 1,600 illnesses each year in the United States with more than 1,500 related hospitalizations and 260 related deaths.1,3 As reporting increases, food producers and regulatory bodies will feel an increased need to surveil all aspects of food production, from soil and air, to final product and packaging. The current standards for pathogenic agriculture and environmental testing, culture-based methods, qPCR and ATP assays are not able to meet the rapid, multiplexed and specificity required to meet the current and future demands of the industry.

At the DNA level, single cell level by PCR, high throughput sequencing, and microarrays provide the ability to identify multiple microbes in less than 24 hours with high levels of sensitivity and specificity (see Figure 1). With unique sample prep methods that obviate enrichment, DNA extraction and purification, these technologies will continue to rapidly reduce total test turnaround times into the single digit hours while simultaneously reducing the costs per test within the economics window of the food safety testing world. There are still growing pains as the industry begins to accept these new molecular approaches to microbiology such as advanced training, novel technology and integrated software analysis.

It is easy to envision that the digital data obtained from DNA-based microbial testing could become the next generation gold standard as a “system parameter” to the food supply chain. Imagine for instance that at time of shipping of a container, a data vector would be produced (i.e., time stamp out, location out, invoice, Listeria Speciation and/or Serovar discrimination, Salmonella Speciation and/or Serovar discrimination, refer toFigure 1) where the added microbial data would be treated as another important digital attribute of the load. Though it may seem far-fetched, such early prototyping through the CDC and USDA has already begun at sites in the U.S. trucking industry, based on DNA microarray and sequencing based microbial testing.

Given that “Third Industrial Revolution” technology can now be used to make microbial detection fast, digital, internet enabled and culture free, we argue here that molecular testing of the food chain (DNA or protein based) should, as soon as possible, be developed and validated to replace culture based analysis.

Broad Microbial Detection
Current microbiological diagnostic technology is only able to test for broad species of family identification of different pathogens. New and emerging molecular diagnostic technology offers a highly multiplexed, rapid, sensitive and specific platforms at increasingly affordable prices. Graphic courtesy of PathogenDx.

References.

  1. Scallan, E., Hoekstra, R. M., Angulo, F. J., Tauxe, R. V., Widdowson, M. A., Roy, S. L., … Griffin, P. M. (2011). Foodborne illness acquired in the United States–major pathogens. Emerging infectious diseases, 17(1), 7–15. doi:10.3201/eid1701.p11101
  2. Scharff, Robert. (2012). Economic Burden from Health Losses Due to Foodborne Illness in the United States. Journal of food protection. 75. 123-31. 10.4315/0362-028X.JFP-11-058.
  3. Mead, P. S., Slutsker, L., Dietz, V., McCaig, L. F., Bresee, J. S., Shapiro, C., … Tauxe, R. V. (1999). Food-related illness and death in the United States. Emerging infectious diseases, 5(5), 607–625. doi:10.3201/eid0505.990502