Overcoming Challenges in Food Safety Analysis
Most people obtain the majority of their food from large supermarket chains that buy in produce from a range of suppliers. Indeed, we have come to rely on numerous globally sourced food products and take it for granted that the food we buy is suitable for consumption. However, with the increasing trend for foodstuffs to be sourced from geographically distant markets, it is becoming more and more difficult for their quality to be assured.
The challenges to the food industry to provide consumers with quality food that is safe to enjoy are therefore increasing. In addition to the expected risks of potential contamination during preparation or degradation during transport, there is a growing trade in food fraud. Unscrupulous food manufacturers intentionally deceive their customers by mis-labelling products to achieve higher profit margins. Low-grade alternatives are labelled and marketed as premium-grade products. A prime example is honey, where honey from certain areas or floral species can attract much higher prices than other honeys. In other cases, products are bulked out with cheaper alternatives, again using honey as an example, honey has been mixed with sugar syrups to increase its volume and elevate sales. Similarly, in the horsemeat scandal, which received much publicity, beef was mixed with horsemeat that is much cheaper. Although these products are not necessarily detrimental to health, it is important to identify the perpetrators to protect genuine producers. The advances in analytical technologies that are being used to combat these dishonest and deceitful practices were explored at Pittcon 2018 and will be built upon at Pittcon 2019.
In addition, there are numerous opportunities for food to become contaminated unintentionally during its journey from the farm to the market place, especially now this is frequently no longer a direct route. Increasing demand and financial constraints have resulted in more chemicals being used to improve yield in both agriculture and animal husbandry. This results in there being a greater risk of the foods we eat containing pesticides or veterinary drugs that could pose a risk to human health. Similarly, contaminants such as heavy metals, may seep into the food chain as a result of man-made mining and manufacturing activities close to the source. Furthermore, the use of more complex synthetic materials to package foods has opened up the possibility of food becoming contaminated from degradation products during storage.
The onus for food quality is now firmly placed on the food manufacturers and sample testing is a key part of every food preparation protocol. Consequently, there is great demand from the food industry for effective and cost-effective means for the routine testing of their products.
With the globalisation of the food trade, many companies producing food products import the different raw ingredients from a wide range of sources and they must ensure that they have confidence in the quality of the ingredients they receive. This has become especially important with the increasing requirement of accurately indicating the presence of ingredients that may be potential allergens, such as egg, milk, nuts. If these ingredients are included in a product without being included on the labelling, there is a real risk that they may be eaten by a person with a severe allergy and give rise to a fatal anaphylactic episode.
Sensitive analytical methodologies that allow easy and rapid analysis of food and drinks are thus needed to confirm the quality and purity of foodstuffs and ensure consumer safety. In addition, it is important that the sample is not degraded or contaminated during the testing procedure. In addition to advances in analytical instrumentation, equipment has been developed to ensure the integrity of the sample is maintained during testing. For example, the programmable cryogenic mill, Freezer/Mill®, was specifically designed for grinding and pulverizing tough or temperature sensitive samples.
Finally, it is not sufficient to demonstrate that the final product is of good quality. A manufacturer must be confident that their product will reach the consumer in the same state as when it was packaged. Testing is thus required to determine how long a product can be stored before it loses quality and whether specific transportation requirements are needed to ensure that the product reaches the consumer in top quality. Such testing evaluates the effects of extended exposure to various environmental factors, such as fluctuations in heat. Specialised equipment is also available to facilitate such accelerated aging tests, such as PolyScience’s refrigerated/heated circulating baths.
This article outlines the research to be presented at Pittcon 2019, about overcoming challenges in food safety and the advances in relevant instrumentation for both food research and industry.
- PolyScience. https://www.azom.com/article.aspx?ArticleID=17358
- Radford S, et al. Sources of Contamination in Food. Encyclopedia of Food Security and Sustainability 2019;2:518 522. https://www.sciencedirect.com/science/article/pii/B9780081005965222646
- SPEX Certiprep. https://www.spexsampleprep.com/knowledge-base/resources/application_notes/0504-164013-SP028_FM_Trace_metal_analysis_Pet_Food_app_note.pdf
Chapter 1 – An Overview of the Analytical Methods Used in Food Testing
The increasing globalization of food trade has raised new issues for ensuring food safety and quality. Food manufacturers now commonly use ingredients and partly processed products sourced from suppliers all around the world. It is therefore becoming more difficult to be sure of the origins and purity of many food products.
Novel analytical techniques with high sensitivity and accuracy are being developed to provide enhanced protection for food producers and consumers. Due to the varying types of contamination that may occur during food production and transportation, a variety of targeted and non-targeted screening methods are required to ensure the safety and authenticity of manufactured food products.
Pittcon 2019 will feature presentations and exhibits from industry leaders striving to facilitate assessments of food quality. This chapter presents examples of some of the more recent developments in food analysis technology.
NMR in food analysis
Advances in nuclear magnetic resonance (NMR) spectroscopy have proved valuable for incorporating non-targeted screening into routine quality assurance testing. It is particularly suited to food analyses as minimal sample preparation is required and no hazardous solvents or chemicals are used. NMR therefore does not damage or contaminate the sample so it can subsequently be re-analysed using other analytical techniques.
NMR is a powerful, non-destructive screening technique that enables detection, identification, and quantification of both key known ingredients and unexpected contaminants and adulterants in a single process. It is sensitive enough to identify even trace quantities of adulterants or contaminants. Furthermore, it can now be fully automated according to standardized procedures so high levels of consistency are achievable between different sites.
NMR spectroscopy has been used effectively to analyse the authenticity of olive oil, honey, beer and wine. Since NMR can also determine the precise amounts of a specific component in the final product, it can be used to provide nutritional values, such as the fat content of dairy products and the alcohol content of beers and wines, and allergen information, such as the presence of milk or nuts.
It has been said that NMR spectroscopy is probably the best non-targeted analytical technique for screening food extracts. This is because it provides much richer information than other comparison of spectroscopic screening techniques and, being highly selective and sensitive, it enables acquisition of both qualitative and quantitative information.
Bruker developed its FoodScreener© platform using NMR technology, which is able to determine the authenticity of food and drink products. For example, it can assign origin for the major wine-producing countries and verify that a honey is accurately described on its label.
The FoodScreener has been used by The Honey Profiling Consortium to comprehensively profile thousands of different honey varieties and geographic origins. The analysis report highlights any violations against the product’s labelling, such as honey variety, region and country of origin, and glucose and fructose concentrations. The latest Honey-Profiling™ 2.0 system has been upgraded to address the increasing need for non-targeted methods to tackle new and sophisticated fraud in honey. A fully automated analysis in conjunction with an expanded reference database facilitates the detection of the most common forms of honey fraud.
Its capabilities include detection of inappropriate bee feeding, verification of botanical variety and geographical origin, quality analysis and detection of deviations in NMR profile from the reference profiles.
There are a range of other spectroscopic methodologies available to food and drinks manufacturers to help them comply with quality and labelling requirements. Indeed, spectroscopy is one of the most commonly used analytical techniques used in the testing of food. There are a number of benefits of spectroscopic techniques that have led to it being so widely used. The array of different radiation types within the electromagnetic spectrum make spectroscopy suitable for broad-reaching applications on a wide range of sample types, from gases to immiscible liquid mixtures to solid powders and chunks. Furthermore, it can provide rapid real-time data and be used in combination with other analytical methodologies.
Mass spectroscopy (MS) is the technique of choice for determining the level of known contaminants, such as the level of pesticides on fresh produce, or the amount of trace elements. It enables rapid, highly sensitive, selective, and robust analyses. MS can be used in combination with either liquid chromatography (LCMS/MS) or gas chromatography (GCMS/MS) or with another MS technique in tandem mass spectrometry (MS/MS). Such combinations can be facilitated by using a complete workflow, as exemplified by ThermoFisher’s TSQ™ 9000 triple quadrupole GC-MS/MS system with specialized Chromeleon™ 7.2 Chromatography Data System software (Thermo Scientific™) for instrument control, data processing, and reporting.
With the increasing stringency of labelling requirements, the manufacturers of food, herbal medicines and dietary supplements are legally required to label food with all ingredients and nutritional information. Trace elemental screening and speciation analysis of food is therefore becoming increasingly important. Although many elements are required in trace amounts for our well-being, they can have detrimental effects if taken in excess. Furthermore, other elements, such as lead, mercury, arsenic and cadmium, offer no nutritional benefits to humans and are toxic. Such elements may enter the food chain through the soybean meal fed to cattle. In addition, with novel packaging technologies emerging, nanoparticle analysis is now also desirable. Packaging containing nanoparticles can extend the shelf life of foodstuffs and reduce the need for preservatives, however, nanoparticles can migrate from packaging into food and many of these contain metallic elements.
A variety of mass spectroscopy methodologies have been developed to help provide simple and robust, analysis methods for quantifying trace elements in food. These include atomic absorption spectroscopy (AAS), inductively-coupled plasma – optical emission spectroscopy (ICP-OES) and inductively-coupled plasma – mass spectrometry (ICP-MS).
Such elemental analysis can be easily and obtained using The Thermo Scientific™ iCAP™ 7000 Plus Series ICP-OES or the Spectro Arcos ICP-OES.
In addition, nanoparticle content can be determined using The Thermo Scientific™ iCAP™ RQ ICP-MS systems.
The majority of foods tested must be dissolved by heating in acid so they can be introduced into a plasma for analysis by ICP-OES or ICP-MS. The Thermo Scientific™ iCE™ 3300 flame atomic absorption system enables the rapid detection of essential and trace minerals in food samples, even if there are high levels of dissolved solids or acidic content. Sensitive, robust and reliable analysis is achieved by high efficiency nebulization via a fully inert impact bead and spray chamber.
The differences in elemental composition of meat from different species have been determined using laser-induced breakdown spectroscopy (LIBS) to enable meat identification. LIBS can thus be used for routine quality control measurements to avoid adulterated meat reaching the market as occurred in the horsemeat scandal. It is also an appropriate technique for determining the macronutrient and micronutrient content of soil. The Aurora LIBS Spectrometer delivers the high spectral resolution and precise gate timing control required for effective LIBS analysis.
Raman spectroscopy is another spectroscopic method utilized for the rapid identification of unknown compounds. It measures the Raman effect, molecular deformations that occur when a sample is exposed to monochromatic light, such as a laser beam. It is a versatile technique that can be used to analyse compounds in solid, liquid, and gaseous states and can even analyse a sample directly through a transparent packing material like glass or plastic. Furthermore, it can be conducted more rapidly than traditional analytical spectroscopic techniques, such as Fourier-transform or infrared spectroscopy. It has been further enhanced by the development of intelligent decision-making software and on-board spectral libraries, which enable molecular fingerprinting.
Today, the production of robust miniaturised Raman equipment has allowed the development of high performance, portable and handheld devices. This means that the technique can now be readily utilised in a production environment to screen raw ingredients and to verify the final products.
B&W Tek’s NanoRam-1064 is a compact, easy-to-use, handheld Raman instrument for non-destructive identification and verification throughout the food production line.
X-ray diffraction (XRD) is another important analytical technique used for the analysis of food products. The sample is exposed to X rays, which are scattered according to the arrangement of atoms. When the x-ray passes sharp edges or goes through narrow slits, the rays are deflected and produce fringes of light and dark bands. The diffraction pattern thus gives a representation of structure.
Far from the fresh and natural diets of our ancestors, we eat an increasing number of processed foods and there are a range of features that we deem necessary in such products. These include, colour, flavour, shelf-life and physical appearance. In order make their products most appealing to consumers, manufactures add a range of agents, including preservatives, antioxidants, stabilisers, emulsifiers, colours and flavours.
As consumers become increasingly selective, the number of additives in foods is expanding. It is thus necessary to have analytical techniques able to routinely monitor the level of such food additives required during manufacturing processes. X-ray diffraction plays a valuable role in this respect, providing information on polymorphism, degree of crystallinity and amorphism all of which inform on the texture and stability of foods.
XRD is also a valuable tool for assessing starch gelatinization in foods, the types of fats in margarines and the cocoa content of chocolate.
The Rigaku MiniFlex X-ray diffractometer can determine phase identification and quantification, percentage crystallinity, crystallite size and strain, and molecular structure.
These techniques and more will be explored in more detail at Pittcon 2019. Some of the presentations detailing the latest research in food safety analysis are highlighted in the next chapter.
- Applied Spectra. LIBS spectrometer. https://appliedspectra.com/products/aurora-libs-spectrometer.html
- B&W Tek. Handheld Raman spectrometer. http://bwtek.com/products/nanoram-1064/
- Bilge G, et al. Identification of meat species by using laser-induced breakdown spectroscopy. Meat Science 2016;119:118_122. https://www.sciencedirect.com/science/article/pii/S0309174016301346#s0010
- Bruker. Honey profiler https://www.bruker.com/products/mr/nmr-food-screening/honey-profiling/overview.html
- Lachenmeier DW, et al. NMR-Spectroscopy for Nontargeted Screening and Simultaneous Quantification of Health-Relevant Compounds in Foods: The Example of Melamine. Agric Food Chem. 2009 Aug 26; 57(16): 7194–7199. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2725748/
- Picó, Y. Mass Spectrometry in Food Quality and Safety: An Overview of the Current Status.’ Comprehensive Analytical Chemistry2015;68. http://dx.doi.org/10.1016/B978-0-444-63340-8.00001-7.
- Rigaku. XRD – https://www.rigaku.com/en/products/xrd/miniflex/app015
- Spectro Arcos. ICP-OES. https://icp-oes.spectro.com/spectro-arcos/application-notes/analysis-of-soy-bean-meal-using-icp-oes/?_ga=2.154935352.1025668699.1551191026-765873300.1551191026 and https://www.spectro.com/products/icp-oes-aes-spectrometers/arcos-inductively-coupled-plasma
- ThermoFisher. Mass Spectrometry. https://assets.thermofisher.com/TFS-Assets/CMD/brochures/eb-72890-food-safety-residue-testing-gc-lc-icp-ms-lcgc-eb72890-en.pdf
- ThermoFisher. ICP-MS. https://assets.thermofisher.com/TFS-Assets/CMD/brochures/br-72713-metals-food-beverage-interactive-br72713-en.pdf
- Yang D and Thomas R. The Benefits of a High-Performance, Handheld Raman Spectrometer for the Rapid Identification of Pharmaceutical Raw Materials. American Pharmaceutical Review 2012. https://www.americanpharmaceuticalreview.com/Featured-Articles/126738-The-Benefits-of-a-High-Performance-Handheld-Raman-Spectrometer-for-the-Rapid-Identification-of-Pharmaceutical-Raw-Materials
Chapter 2 – Defining Compliance for Food Safety
Food-borne diseases are a significant public health burden that is largely preventable. With a view to minimising morbidity and need for healthcare resources as a result of eating contaminated food, the FDA has finalized seven major rules to implement the Food Safety Modernization Act (FSMA) introduced by President Obama in 2011.
The responsibility for ensuring the safety of the food supply is a shared between many different companies in a global supply chain. To avoid everybody leaving quality checks to the next step in the chain, the FSMA designates clear specific actions that must be taken at each point along the chain to prevent contamination.
The FDA details sound analytical practices and methodologies suitable for ensuring food safety and uses these techniques to routinely analyse commercially available food and food supplements to ensure that they are in compliance with applicable regulations. The list of techniques is regularly updated as more effective technologies are developed. Furthermore, the FDA Center for Food Safety and Applied Nutrition (CFSAN) undergoes ongoing research to identify the best technologies and methodologies for the analysis of foodstuffs.
Not all companies will have adequate analytical technologies in-house to meet their screening requirements. In such cases, when a problem is revealed during routine testing, samples will be sent to a specialised diagnostic laboratory for furthermore detailed investigation with advanced instrumentation. In this way a food manufacturer has the advantage of being confident that their products are being analysed to the highest level according to the latest technical expertise, without having to keep abreast of such developments themselves. As a diagnostic food laboratory undergoes third-party assessment to gain accreditation (The ISO 17025 standard), a manufacturer has assurance that their analyses will meet regulatory quality control requirements.
Similarly, in the UK there is legislation that ensure that the methods used for sampling and for laboratory analyses meet scientific standards, satisfy the specific analytical, testing and diagnostic need of the laboratory concerned, and offer sound and reliable analytical, test and diagnostic results.
There are similar regulations are applicable to food research. The US Department of Agriculture (USDA) provides an educational service to ensure that everyone has access to the latest dietary guidance based on scientific evidence. The Center for Nutrition Policy and Promotion (CNPP) is responsible for developing and promoting dietary guidance that links the best evidence-based scientific research to the nutrition needs of Americans.
In 2013, the USDA Food Safety and Inspection Service (FSIS) began conducting whole genome sequencing (WGS) analyses on isolates obtained from meat, poultry, and egg product samples in routine and exploratory sampling programs to provide data for the identification of and prevention and control for the presence of pathogens, such as Listeria and Salmonella. Stephanie Defibaugh-Chavez of USDA will be giving more details on this initiative in her presentation at Pittcon 2019 entitled “Regulatory and Surveillance Applications for Use of WGS Data – How the Data is Changing the Way We Assess Regulatory Compliance and Food Safety Hazards”.
In addition, to enhance listeriosis surveillance and control by providing improved understanding of phylogenetic relationships the FDA, CDC, and USDA-FSIS have been analysing WGS data using free, open-source SNP-based approaches. The nucleotide differences among the genomes under investigation are mapped for comparison to a reference genome. Recent advances have increased the discriminatory capacity of WGS and this has helped determine stronger links between microbe isolates from food, the environment, and patients. This has facilitated more focussed epidemiologic investigations, and the solving of more outbreaks. WGS has transformed listeriosis outbreak surveillance and is being implemented for other foodborne pathogens.
ThermoFisher provide a range of DNA sequencing solutions to cover all research application needs, from whole genome sequencing to targeted sequencing of specific genomic regions, including the Ion Torrent for Next-Generation Sequencing.
In addition to environmental contamination, there are numerous additional potential points of contamination along the food production chain. These include transport of raw materials to the factory where they will be processed, the handling and processing of raw materials, eg, cleaning, sterilization, mixing and cooking of the ingredients to produce the final product, packaging and transportation and storage.
With advances in the materials used for food packaging, packaging has become an increasingly common source of food contamination, Ironically, many of the novel packaging techniques were developed to maintain the freshness of the contents more effectively and allow prolonged storage of food products. This has been achieved by adding a range of different types of additives, such as antioxidants, stabilizers, lubricants, anti-static and anti-blocking agents. However, it has been found that these additives can seep from the packaging into the food it protects.
Due to the potential for toxic compounds to enter the food chain there is an urgent need for the regulatory control of food packaging. Indeed, this has been acknowledged by the FDA who are conducting their own investigations into emerging chemical contaminants on which to base regulatory decisions. Several recent case studies of such research will be outlined by Luke K Ackerman of the FDA in his presentation at Pittcon 2019, “Analytical Challenges and Methods for the Direct/Analysis of Food & Food Contact Materials: Recent FDA-CFSAN Research“.
Various analytical methods have been developed to analyse packaging additives in foodstuffs. For example, analyses using direct analysis in real-time high-resolution mass spectrometry (DART-HRMS). Differential Scanning Calorimetry (DSC), Scanning Electron Microscope (SEM), LC-MS/MS and GC-MS revealed that dyes from certain high-impact polystyrene food containers were migrating into food. In this research the dyes were identified using the Thermo Scientific™ Q Exactive™ Hybrid Quadrupole-Orbitrap Mass Spectrometer. This benchtop LC-MS/MS system provides high performance untargeted or targeted screening suitable for ensuring food safety.
The combination of chromatography and spectrometry technologies provides the powerful separation power and high-resolution and specific identification and quantification required in food safety testing to meet regulatory requirements.
Many suppliers of specialised instrumentation for conducting chromatography-mass spectrometry analysis of foodstuffs will be present at Pittcon 2019 to discuss the latest advances. Phenomenex, Shimadzu, and ThermoFisher Scientific, to name but a few, will be on hand to discuss their high-performance solutions for detecting contaminants in routine food quality screening. These include the Q Exactive™ LC-MS/MS system, the NX Series of GC-MS and GC-MS/MS instruments. In addition, Gerstelus will be presenting their GERSTEL MultiPurpose Autosampler that provides numerous options for introducing a sample into a gas chromatograph and Phenomenex will be available to discuss their Luna range of ultra-pure silica-based HPLC columns that offers an extensive variety of selectivity for reliable and reproducible separations.
- FDA. Food Safety Modernization Act (FSMA). https://www.fda.gov/food/guidanceregulation/fsma/
- Gerstelus. GC autosampler https://www.gerstelus.com/products/mps-for-gc/
- Global Food Resource. Food Laboratory Testing. https://globalfoodsafetyresource.com/food-laboratory/
- Jackson BR, et al. Implementation of Nationwide Real-time Whole-genome Sequencing to Enhance Listeriosis Outbreak Detection and Investigation. Clinical Infectious Diseases2016;63(3):380–386. https://doi.org/10.1093/cid/ciw242
- Lago MA and Ackerman LK. Identification of print-related contaminants in food packaging. Food Additives & Contaminants: Part A 2016;33(3):518–529. https://www.researchgate.net/profile/Luke_Ackerman/publication/291340416_Identification_of_print_related_contaminants_in_food_packaging/links/5ad76121458515c60f573686/Identification-of-print-related-contaminants-in-food-packaging.pdf
- Lau O-W and Wong S-K. Contamination in food from packaging material. Journal of Chromatography A 2000;882(1–2):255 270. https://www.sciencedirect.com/science/article/pii/S0021967300003563
- Nerín C, et al. Food contamination during food process. Trends in Food Science & Technology 2016;48:63-68. https://www.sciencedirect.com/science/article/pii/S0924224415301370
- Phenomenex. HPLC columns. https://www.phenomenex.com/Products/HPLCDetail/luna
- Shimadzu. GC-MS. https://www.ssi.shimadzu.com/products/gas-chromatography-mass-spectrometry/index.html
- ThermoFisher. DART-HRMS. https://www.thermofisher.com/order/catalog/product/IQLAAEGAAPFALGMAZR
- ThermoFisher. DNA sequencing equipment. https://www.thermofisher.com/uk/en/home/life-science/sequencing/dna-sequencing.html
- USDA. Food and Nutrition. https://www.usda.gov/topics/food-and-nutrition
Chapter 3 – Anti-Counterfeit Technology
Many of the food products reaching the supermarkets have ingredients sourced from numerous suppliers across the world. This increasingly complex supply chain has created new challenges for keeping track of the origins of foodstuffs and beverages made available to consumers. Some unscrupulous suppliers have been taking advantage of this by intentionally mislabelling consumables for financial gain.
Indeed, food fraud has become an increasingly prevalent practice that has the potential to jeopardise the livelihoods of honest producers and also has implications for food safety. Consequently, there have been concerted global initiatives to uncover and eradicate dishonest and deceitful practices in the food industry. Advances in analytical technologies that allow identification of the exact composition of foodstuffs have played a key role in combatting food fraud. This was a big topic at Pittcon 2018 and a summary of key presentations can be found in Food Safety at Pittcon 2018. The very latest advances will be highlighted at Pittcon 2019.
Patricia Atkins of SPEX CertiPrep, will be illustrating the potential sources of heavy metal exposure and the role of ICP-OES, ICP-MS and LC-ICP-MS technologies in determining the presence of heavy metals in her oral session entitled “Contamination, Adulteration and Counterfeiting: An Examination of Sources and Concentrations of Heavy Metals Present in Food, Spices, Beverages and Drinking Water”.
We are exposed to heavy metals, such as lead, from a variety of sources in our everyday lives. The World Health Organization contends that the food and drinks we ingest may be the source of the largest contribution to the global intake of heavy metals. Indeed, lead is commonly found in drinking water supplies.
Lead is one of the most ubiquitous toxic substances, being present in soil, plants, water, and air. Much of the lead in the environment comes from pollution from industrial activities and the daily use of lead-based products. Although most of the lead is removed at water treatment works before it is piped to our homes, there still remains a significant amount of old lead piping from which lead can leach into drinking water.
Numerous producers of specialised mass spectroscopy instrumentation and accessories for elemental analysis will be present at Pittcon 2019. These include Spectro with their range of ICP-OES analysers, such as the Spectro Arcos™, Texas Scientific Products with a broad portfolio of accessories and components for ICP-MS, and High Purity Standards who provide quality single and multi-element calibration standards for ICP & ICP-MS.
Elemental analysis can also be achieved using laser-induced breakdown spectroscopy (LIBS). This atomic emission spectroscopic technique uses a focused pulsed laser beam to generate plasma from the sample, which emits electromagnetic radiation as the plasma cools down. Multiple elements can be screened for simultaneously and spectra can be obtained more rapidly than traditional analytical techniques for characterisation and identification of foods and little to no sample preparation is required.
Recently, the technique has been miniaturized into a handheld LIBS device that is capable of analysing any element and allows instant analyses at the point of need. This provides an easy means for spot-checking food products for signs of fraudulent practices.
The use of LIBS in the detection of coffee fraud will be explored at Pittcon 2019 in a talk by Banu Sezer of Hacettepe University that is entitled “LIBS: Detection of Coffee arabica Adulteration”.
Coffee is in high demand around the world and is of great economic importance to the countries that produce and export it. Furthermore, importers of coffee need to be assured that they are receiving the authentic product. Testing for purity and the detection of extraneous content, such as coffee husk and stems, maize, barley, wheat, soybean, rye, thus plays an important role in the coffee trade. These substances have been commonly used in the adulteration of roasted coffee to bulk up its volume. The capability to rapidly, non-subjectively, and reproducibly analyses roasted ground coffee for adulteration is crucial.
A recent study used Applied Spectra’s Aurora LIBS spectrometer to rapidly discriminate between coffee arabica, durum wheat, corn and chickpea samples. LIBS provided impressively low limits of detection for chickpea, corn and wheat adulteration of coffee arabica and thus represents a viable solution for preventing unfair competition in the coffee market by accurate determination of coffee quality.
Applied Spectra will be on-site at Pittcon 2019 to discuss how their LIBS spectrometers strike the right balance between spectral resolution and detection sensitivity to provide precision elemental analysis. A range of other producers will also be on-hand to discuss their range of LIBS solutions, including Rigaku with their durable KT-100S handheld metal analyser.
The portability of handheld analytical devices makes it possible to readily conduct analyses wherever they are needed. This is especially relevant in the battle against food fraud where widespread routine screening is required for success. The latest advances in hand-held analytics will be showcased at Pittcon 2019 and are highlighted in the next chapter.
- Applied Spectra. https://appliedspectra.com/products/aurora-libs-spectrometer.html
- Atkins P. Our Daily Dose of Poison: A Look at Lead in the Food Supply. Spectroscopy 2017;32(10):12–17. http://www.spectroscopyonline.com/our-daily-dose-poison-look-lead-food-supply-0
- High purity standards. calibration standards for ICP & ICP-MS. https://highpuritystandards.com/icp-ms-multielement-standards/
- Markiewicz-Keszyckaa M, et al. Laser-induced breakdown spectroscopy (LIBS) for food analysis: A review. Trends in Food Science & Technology 2017;65: 80 93. https://www.sciencedirect.com/science/article/pii/S0924224417300377
- Rigaku. Handheld LIBS spectrometer. https://www.rigaku.com/en/products/libs/katana
- Sezer B, et al. Capabilities and limitations of LIBS in food analysis. Trends in Analytical Chemistry 2017;97: 345-353. https://www.sciencedirect.com/science/article/pii/S0165993617302753#sec2
- Sezer B, et al. Coffee arabica adulteration: Detection of wheat, corn and chickpea. Food Chemistry 2018;264:142-148. https://www.sciencedirect.com/science/article/pii/S0308814618308288
- Spectro. ICP-OES analysers. https://www.spectro.com/industries/food
- Texas Scientific Products. Components of ICP-MS equipment. https://www.txscientific.com/icp–icp-ms-c3.aspx
Tocia AT, et al. Coffee Adulteration: More Than Two Decades of Research. Critical Reviews in Analytical Chemistry 2016;46(2):106–115. http://dx.doi.org/10.1080/10408347.2014.966185
Chapter 4 – Rapid Methods for Food Analysis
The achievement of portable and even hand-held analytical devices has tremendously facilitated the detection of food fraud. Samples for authenticity and purity screening are typically collected at farms, slaughterhouses, border inspection points, and retail shops. These can now be analysed on site, obviating the need for immediate transportation to a control laboratory. Although this has speeded up the acquisition of analytical results, there is still the need for the data declaring a sample to be non-compliant or compliant to be rapidly communicated to the relevant authorities and traders.
At Pittcon 2019. Michel Nielen of Wageningen University and Research will be describing a project aimed to address this in his talk “The Food Analysis Revolution on Your Smartphone”.
The EU project ‘FoodSmartphone’ is developing smartphone-based (bio)analytical sensing and diagnostic tools that enable easy wireless data transfer of quality and safety data obtained during on-site pre-screening to the servers of relevant stakeholders. The technology will have a simple user interface making technologies currently only used by specialist food technicians available to any user. In this way, the general public will be able to join the crusade against food adulteration.
In addition, Project ‘FoodSmartphone’ will provide a valuable tool in the determination of allergens in foodstuffs. Not only will people with severe food allergies be able to analyse a purchased food prior to eating it to protect their health, they would be able to report any inadequate food labelling directly to the relevant authorities so the problem can be swiftly rectified.
Much research and development is still required before this will become a reality, but the very feasibility of a food quality testing tool being available to the general public has raised considerable excitement. A number of technologies will need to be redesigned to make them compatible with smartphones. The most popular optical approach to smartphone detectors is based on colorimetric reactions such as in LFIA or ELISA. Hudson Robotics, who will be at Pittcon 2019, produce Solo, which is an automated fully-capable compact ELISA preparation system.
The poster sessions at Pittcon 2019 provide further opportunity for you to discuss the latest advances directly with research team members. There will be posters covering all aspects of food safety; for example, Neo Yang of BiOptic Inc will be presenting a poster entitled “Rapid Genetic Identification of Meat”. As mentioned in Chapter 1, rapid identification of the origins of meat are important to detect cases of premium meat being bulked out with cheaper alternatives. One means of identifying meat from different species is analysis of elemental composition using laser-induced breakdown spectroscopy (LIBS) to enable meat identification. Neo Yang will be detailing a novel workflow for rapidly identifying meat based on its genetic fingerprint. This was achieved using BiOptic’s portable PCR-mediated DNA amplification instrument, Qampmini™ Thermal cycler, and Qsep1™ Bio-Fragment Analyzer. Manufactured meats made of different species were detected simultaneously in one PCR reaction. Furthermore, the portability of the instruments and straightforward sample preparation provided a complete and systematic workflow that can be easily employed in slaughter houses and meat-processing facilities. The system also has potential applications in plant and fish identification and for the screening of genetically modified produce in a cost-effective manner.
- BiOptic. Portable genomic screening instrumentation. https://www.bioptic.com.tw/index.php?action=productDetail&fcid=4&id=27
- FoodSmartPhone. http://www.foodsmartphone.eu/videos.html and https://www.youtube.com/watch?time_continue=4&v=lXceX3TITzs
- Hudson Robotics. https://hudsonrobotics.com/products/other-products/compact-solo-based-elisa-workcell/
- Ross GMS, et al. Consumer-friendly food allergen detection: moving towards smartphone-based immunoassays. Analytical and Bioanalytical Chemistry 2018;410:5353–5371. https://link.springer.com/content/pdf/10.1007%2Fs00216-018-0989-7.pdf
Recent changes to food safety legislation placed the onus for food quality firmly on the food manufacturers. The regulations clearly stipulate who is held responsible for ensuring the purity of foodstuffs at each stage of the manufacturing process. In addition, labelling requirements dictate that food manufactures are legally required to list all ingredients and highlight any potential allergens. This requires the testing of raw ingredients that are bought in to ensure that there are no unexpected constituents or contaminants.
In addition, the increasing prevalence of food fraud in which premium components are replaced or bulked up with cheaper alternatives for financial gain has necessitated routine spot checks to confirm the authenticity of marketed food and drink products.
All of these require sensitive and reliable analytical techniques that provide results rapidly. Consequently, there is great demand from both the food industry and food regulators for efficient and effective methodologies for the routine testing of foodstuffs at every stage of the manufacturing process.
Pittcon 2019 will illustrate how researchers are continually striving to address this need with the development of new, ever more sensitive technologies. The FDA details sound analytical practices and methodologies suitable for ensuring food safety. Introduction into routine food testing of the novel techniques that will be discussed at Pittcon 2019 will greatly facilitate compliant food safety analyses.
From exposure to pathogens to high-tech packaging, there are numerous potential points at which a food product can be become contaminated with agents harmful to the health of the consumer. Handheld compact devices for on-site whole genome sequencing and LIBS spectrometry allow bacteria to be readily identified in foodstuffs. In addition, the genomic data obtained from pathogens, such as Listeria and Salmonella, have facilitated more focussed epidemiologic investigations, and the solving of more outbreaks. Similarly, DART-HRMS has enabled identification of dyes from packaging in foodstuffs.
LIBS spectrometers, with their capacity for providing precision elemental analysis have also helped in the detection of food fraud, such as adulteration of coffee and mis-labelled meat products. The recent addition of handheld LIBS devices provides an easy means for spot-checking food products for signs of fraudulent practices.
NMR spectroscopy is also a key player in the battle against fraud, being able to effectively analyse the authenticity of olive oil, honey, beer and wine. Its use in conjunction with spectral libraries allow the ready identification of adulterated products. This was highlighted at Pittcon 2018 by the success of Bruker’s NMR-based FoodScreener that is being used in a global initiative to eradicate fraudulent honey sales. The capacity of this instrumentation has now been further extended and details will be available at Pittcon 2019.
Since NMR can determine the precise amounts of a specific component in the final product, it is also used for analysing a product to provided ingredient and allergen information for the label.
The technique of choice for determining the level of known contaminants continues to be mass spectroscopy (MS), but various novel variations have been developed to increase the sensitivity for specific challenging applications. These include atomic absorption spectroscopy (AAS), inductively-coupled plasma – optical emission spectroscopy (ICP-OES) and inductively-coupled plasma – mass spectrometry (ICP-MS). In addition, handheld Raman spectroscopy instruments have been developed to enable non-destructive identification and verification throughout the food production line.
The achievement of a variety of portable and hand-held analytical devices has tremendously facilitated the detection of food fraud. Samples for authenticity and purity screening can now be analysed on site, obviating the need for immediate transportation to a control laboratory.
Pittcon 2019 will also provide details of Project FoodSmartphone which is developing analytical techniques that can be integrated into a smartphone. Samples could then be tested wherever and whenever is needed. In addition, the data could be wirelessly transmitted instantly as necessary. Furthermore, this would open up the potential for the general public to become involved in the testing of the products they buy for both purity and accurate labelling of ingredients.
Every year, incredibly more powerful and ingenious technologies are being devised in order to ensure the quality of our food can be easily ensured. The examples highlighted in this article, and more, will be discussed in more detailed during Pittcon 2019, which is taking place at the Pennsylvania Convention Center in Philadelphia from 17 to 21 March 2019.
The presentations and exhibits at Pittcon 2019 will provide insight into the analytical advances likely to further enhance food safety through routine screening in the future. Visit the Pittcon 2019 guide to learn more about the symposia, oral presentations and short courses that will be taking place.
In addition, numerous market-leading providers of analytical equipment, products and services specially tailored for the analysis of foodstuffs will be on-site at Pittcon 2019 to discuss the latest additions to their capabilities.