Latest Advances in Food Safety: an Industry Guide

Introduction:

The deliberate or accidental contamination of food products is a prominent issue with wide-ranging consequences in the 21st century. It can encompass multi-billion-dollar fraud, hazards to public health and even deliberate attempts to harm human life.

The Chinese melamine scandal of 2008 and the European horsemeat scandal of 2013 made international headlines. Also in addition to food fraud, international governments are confronting the prospects of food contamination being used as a biological weapon for terrorism.

In order to combat these potential threats, regulatory agencies are taking measures to protect public health. For example, in the USA, the FDA has recently introduced the first US legislation against deliberate food adulteration, requiring manufacturers to put much more stringent protections in place throughout the food production pipeline.

Meanwhile, in Europe, recent legislation has seen a measurable impact on levels of fish fraud, an activity that poses a threat to consumer health, as well as threatening fish sustainability and the livelihoods of fish producers.

In this guide we will look at food safety issues in depth and explore the emerging technologies being used to assist regulators in fighting these modern-day challenges. Through case studies we will cover adulteration and contamination of food and drinks, and also consider how food analysis assists the industry in quality control.

Advances include the use of NMR spectroscopy to analyze olive oil, wine and honey, laser diffraction to ensure coffee and chocolate quality, and ion chromatography to assess drinking water safety.

You can hear about the very latest research and advances in this area at this year’s Pittcon, which will be taking place in Chicago March 5-7 2017. The Pittcon symposium on food analysis will be looking at innovative analytical methods, including novel applications of NMR, wireless sensors and DNA barcoding.

Presentations will come directly from manufacturers at the forefront of advancing these technologies, as well as from the analysts and regulators who are putting them to use in real-life scenarios.

For example, the symposium “Food Analysis – Looking Beyond Mass Spectroscopy”, organized by Katherine Carlos and Lowri deJager of the US FDA, will feature a presentation from GE on “Multivariable RF Based Sensors for Food Quality and Safety” which will outline the development of wireless technology in food quality control.

In another presentation, “Food Authenticity: DNA Barcoding and Genomics”, Rachel Gloyer from the UK-government affiliate FERA Science Ltd, will show how recent developments in DNA sequencing are being applied to detecting and tracking food pathogens.

Furthermore, all of the major spectroscopy and analytic science companies will be in attendance at this year’s exposition, including Perkin Elmer, Bruker, Renishaw, Metrohm and Wyatt Technology, making Pittcon an unmissable opportunity to see and hear the latest trends and advances in food analysis.


Chapter 1 – Recent Challenges in Food Safety

The issues of food safety and adulteration are not new, but they have taken on different dimensions and guises in the 21st century. We now live in a globalized world where food is frequently produced in one country and served up on plates thousands of miles away.

Imported food poses a challenge for food safety due to both legal and logistical restrictions on inspections and standards. And with access to global markets and increased competition, food manufacturers may have additional incentives to cut corners and flout the law, sometimes at the expense of the consumer’s pocket and their health.
We also live in a post-9/11 era where the threat of terrorism is a presence in our lives. Bioterrorism, including through food-supply contamination, is a legitimate concern that governments have had to take significant steps against in recent years.

This year’s Pittcon will feature presentations and exhibits from industry leaders, who are working to create the next generation of food safety technologies. The challenges that face regulators are substantial, but these advances are delivering new ways to tackle them and enhance the protection of producers, consumers and public health.

Food safety and food fraud in the 21st century

In recent years, there have been food safety incidents that made international headlines, which highlight the need for ongoing vigilance and continued innovation.

For example, in 2008, around 300,000 babies in China were made ill by formula milk that had been contaminated with the industrial chemical melamine and six of them died from kidney damage. The melamine, which is dense in nitrogen, was thought to have been added to artificially inflate tests for protein content, allowing the product to be watered down. The Chinese government made several prosecutions in relation to the contamination, which also resulted in the collapse of the milk production firm Sanlu.

Even more recently, in 2013, consumers in Europe were shocked to discover that they may have unknowingly been consuming horsemeat, when it was found that processed meat products, such as frozen beef burgers, mince and ready meals, contained horse DNA. The scandal was thought to have been through economically motivated intentional food fraud – horse meat is much cheaper in some European countries than other types of meat. The discovery also highlighted the complex chains of food supply stretching across the European continent, which can make keeping track of foods origins and suppliers extremely tricky.

Bioterrorism

In 2011 an outbreak of E. coli in Northern Germany affected over 3000 people, leading to the deaths of over 50. The episode was traced back to fenugreek sprouts, which it is believed may have been grown from contaminated seeds imported from Egypt. However, in a report published earlier this year, researchers who modelled the spread of the outbreak said that the speed at which it emerged and the virulence of the particular strain of E. coli suggest the possibility it was deliberately caused.

What is being done?

In response to cases like these, governments and regulatory authorities have been taking action to attempt to reduce the risk of food adulteration through improved prevention and detection.

– The USA responds to the threat of bioterrorism<
In 2006, the US government introduced a new ruling that is intended to help safeguard the food supply against acts of intentional adulteration. Previously, under the Bioterrorism Act, introduced in 2002, food businesses were required to register with the US Food and Drug Administration and provide them with shipment information and other records.

Now the Food Defense rule, which is the first specific US regulation against intentional adulteration, takes this further. Large food companies (smaller companies are excluded from the regulations) must now have a written food defense plan. This involves assessing vulnerability to attack at each stage of the food manufacturing process. Once identified, manufacturers must then put in place mitigation strategies to reduce the risks including monitoring procedures and corrective actions.

– EU rules drastically cut rate of fish mislabeling
Another type of food fraud that affects both the USA and Europe is seafood mislabeling. Many types of fish are indistinguishable from each other, particularly when delivered in fillets or slices meaning they are easy to substitute or mislabel. This practice poses harms for conservation and sustainability of fish species, as well as for consumers who are being defrauded and potentially exposed to unknown toxins. It is also detrimental to fish producers who may be economically disadvantaged against competitors who are operating illegally.

Recent analyses in Europe that looked at the most commonly bought types of fish found that species, such as cod, tuna, hake and plaice, were mislabeled in up to 40% of cases. But the advent of widespread genetic testing has allowed the rate of mislabeling to be tracked and assessed in light of ever-tightening EU rules on food labeling, tracing, and standardization, as well as increased public awareness of fish fraud in recent years. Data published in 2015 suggested that the effect of these factors has been a marked turnaround in rates of mislabeling, which averaged 4.9% in a cross-Europe survey. By contrast, the fight against fish fraud has made less of an impact in the USA, perhaps due to less stringent, and often non-binding, regulations.

The latest advances under one roof

New developments in technology are emerging to assist regulators in meeting the challenges of food safety. This year’s Pittcon offers the opportunity to hear from leading experts on the expanding armamentarium of tools and techniques available to identify food fraud and keep our food safe.

As well as more familiar analysis techniques such as NMR and MS, the symposium “Food Analysis – Looking Beyond Mass Spectrometry” will also highlight the advantages of Raman microspectroscopy, a non-destructive approach to characterize the composition of complex food products and the use of wireless sensor technologies and DNA barcoding in the food industry.

We will also hear directly from the US Food and Drug Administration and the UK government-affiliated FERA Science, to find out how lesser known technological applications are being put to use to protect citizens right now.

Furthermore, there are exhibits from companies including Perkin Elmer, Metrohm, Bruker, Renishaw and Wyatt. These include technologies such as the Perkin Elmer AxION 2 Time-of-flight mass spectrometer, a device that provides high-speed analysis of food contaminants, and Metrohm’s beverage analysis devices that harness Raman spectroscopy and ion chromatography.

References


Chapter 2 – Case Study: Adulteration and Authentication of Olive Oil

Olive oil is one of the world’s most adulterated products. What are the reasons for this? Firstly, it’s a product that is growing in popularity – consumption in the US has grown by 50% over the last 10 years. It’s also one that’s able to command a premium price in comparison with other types of oil, as consumers are willing to pay for the product’s unique health and sensory qualities. This is especially true for extra-virgin varieties. Hence, olive oil is prime for economically motivated adulteration.

A recent study of extra-virgin olive oils on sale in the USA – the world’s dominant consumer of olive oil – found that 73% of samples taken from the five leading brands failed to meet international sensory standards, indicating that they had been oxidized, were of poor-quality or had been adulterated with cheaper refined oils. And the US Food Fraud database contains over 260 incidents of oil adulteration. Examples of adulteration include dilution or substitution with other types of oil, such as hazelnut, sunflower or soybean oils. Additionally, fraudsters may add other chemicals that allow the substances to pass routine screening tests.

Developments in olive oil analysis

Fortunately, there are a number of advances in food analysis that are helping to tackle this particular variety of food fraud, and many of the companies at the forefront of this will be present at this year’s Pittcon. These technologies are intended to provide rapid, reliable and cost-effective approaches to detect olive oil adulteration and overcome the drawbacks of other more time-consuming and labor-intensive methods such as gas chromatography/mass spectrometry and high-performance liquid chromatography.

For example, in a recent study, researchers showed how the Perkin Elmer AxION 2 time-of-flight (TOF) mass spectrometer (MS) integrated with the company’s AxION Direct Sample Analysis (DSA) system could be used to distinguish soybean oil contamination in olive oil samples.

Their approach was to look at the relative quantities of fatty acids, which are present in characteristic proportions in pure olive oil.

The researchers purchased olive oil and soybean oils from a local supermarket and diluted them to 1% in iso-propanol with ammonium acetate. They first characterized the fatty acid composition of the two oils separately, which showed that soybean oil had a higher response ratio for linoleic and linolenic acid to oleic acid, compared with olive oil.
They then mixed to the two oil types in various concentrations ranging from percentages of 5 to 50% soybean oil. They showed that, as the concentration of soybean oil increased, so too did the response ratio for linoleic acid and linolenic acid to oleic acid. For example, at 10% concentration of soybean oil, the response ratios were almost double compared with pure olive oil.

The team say the findings show the potential for DSA/TOF to rapidly detect olive oil adulteration with soybean oil. The samples required minimal preparation and took only 30 seconds to analyze, which they add will improve lab productivity and cut operating costs.

A new take on familiar technology

An alternative and well-established technique for analyzing oil samples is infrared (IR) spectroscopy. This method can be used to check if a substance has been adulterated and, if the adulterant is known, to quantify it.

In a study using attenuated total reflectance fourier-transformed IR on the Perkin Elmer Spectrum Two, researchers showed how an Adulterant Screen algorithm could accurately and sensitively detect and identify adulterants in olive oil samples. The approach works by creating two libraries of spectra: one of unadulterated reference samples and one of pure adulterants.

When a sample spectrum is scanned, the algorithm compares it with a model generated from the reference materials, before adding each adulterant in turn to the model. If an adulterant improves the fit of the model to the sample spectrum, it indicates a likelihood that it can be found in the sample.

The researchers explored the method by first creating a reference library of spectra from 24 unadulterated olive oils. They then obtained and saved spectra of sunflower and rapeseed oils, which were the adulterants in question in the study. After this, the team tested samples of olive oil adulterated with different concentrations of these two oils.

They found that all of the adulterated samples were classified as failing the screen by the algorithm; the only one to pass was a pure sample of unadulterated olive oil.

Furthermore, the algorithm is also able to give an estimate of the level of the adulterant by calculating its relative contribution to the total spectrum. This can save further time by removing the need to generate extensive quantitative models, the researchers say.

Bruker, who will also be exhibiting at this year’s Pittcon, produce a line of FT-NIR spectrometers that can perform non-destructive analysis of food samples for adulterant screening. The method can be applied by comparing a single spectrum from the sample in question to spectra from un-adulterated samples of known quality, therefore providing a non-targeted screening solution.

Bruker have also developed automated software that can perform each step of sample analysis in sequence with minimal operation required.

RF-based sensors in food quality monitoring

At the Pittcon symposium on food analysis Cheryl Surman and Nandini Nagraj of GE Global Research will be demonstrating how RF-based sensors can be tailored for use in food quality monitoring. They will outline how sensor components used alongside chemical or biological films can be configured for measuring multiple parameters simultaneously, providing an opportunity for multivariate analysis. The team will also provide an update on the latest developments in RF readers including state-of-the-art technology created by KemSense.

References


Chapter 3 – Case Studies: Honey and Chocolate

Scientists have recently been applying nuclear magnetic resonance (NMR) profiling to the detection of fraud in the honey trade.

Honey is another product apt for economically motivated adulteration. It is both in high demand, and in short supply, due to a number of reasons including pressures on bee colonies. Additionally, consumers are willing to pay a premium for products originating from certain countries or for particular floral varieties. As a result, adulteration has been on the increase.

Detecting honey adulteration using NMR

Types of adulteration include mixing honey with cheap-to-produce sugar syrups and attempting to disguise the geographic origin by filtering out pollen. These types of food fraud can be difficult to detect, but NMR provides a non-targeted and sensitive solution. This has recently been exploited in a project called the Honey Profiling Consortium carried out in association with Bruker BioSpin, who will be exhibiting at this year’s Pittcon.

The project uses Bruker’s FoodScreener platform, which analyzes food and drink authenticity using 1H-NMR. Multiple labs using the technology collaborated to share results from their honey analyzes in order to create a comprehensive profile of 1000s of honeys of different varieties and geographic origins. The consortium also profiled honeys with known levels of adulterant by mixing honeys with various sugar syrups.

Based on this wealth of data, the consortium were able to generate statistical models that will indicate when a newly tested honey differs significantly from the established patterns recorded in the database. Any deviation could be a sign of adulteration.

Bruker operates the system by conducting remote data analysis; testing is carried out at local labs but the statistical testing is done on Bruker’s own servers. Bruker say this helps to ensure the comparability and robustness of results and also allows new statistical models and targeted parameters to be implemented quicker. The Bruker FoodScreener itself is also designed to be highly automated to reduce the influence of any operator factors. For example, the system can perform tuning, temperature matching, pulse-width calibration and spectral processing without the need for operator input.

When a honey is tested in a third-party lab, Bruker delivers them an automatically generated “traffic light” report. By systematically comparing the NMR signals generated from the honey, the report will flag any violations against the product’s labeling, such as honey variety, region and country of origin, and glucose and fructose concentrations. Because of the non-targeted abilities of NMR, the report will also include the absence or presence of any additional signals that would be expected in the authentic honey.

At this year’s Pittcon, Clark Ridge from the US FDA will explore the use of NMR in food analysis. The presentation will include an overview of the technology, as well as looking at the advantages and disadvantages of some specific applications including quantitative NMR, “iso-tagging” and chemometric “fingerprinting”.

Measuring particle size distribution of chocolate

Also present at Pittcon will be Malvern. Their particle sizer, the Mastersizer 3000, accurately measures particle size using laser diffraction in wet and dry dispersed particulate samples. This method is useful in food analysis due to the influence of particle size on product characteristics such as color, taste and solubility. For example, particle size has a major role in determining texture and mouthfeel of chocolate. Research has shown that when a significant number of particles exceed 30µm, consumers report that the chocolate is of lower quality. Assessing and controlling particle size during manufacture can help ensure product quality control and also lower costs for manufacturers.

In an experiment by Malvern researchers, they used the Mastersizer 3000 to analyze three different types of chocolate – dark, milk and white – all of which contain different combinations of particulate ingredients. The method was able to identify three clear separate profiles of particle size for the different types of chocolate. It showed that dark chocolate had a greater density of smaller sized particles compared with the other two chocolate types, indicating that it should have a smoother and luxurious texture. The analysis was able to provide the proportion of particles above 30µm in each type of chocolate – only 2.13% in dark chocolate, compared with 12.56% and 17.32% in white chocolate.

Ion chromatography analysis of dairy products

Another method that is a standard in food analysis is ion chromatography. Industry leader Metrohm will be exhibiting at this year’s Pittcon. Their ion analysis products are capable of inline ultrafiltration and dialysis to automate sample preparation, helping to reduce the number of manual steps and improve reproducibility.

Ion chromatography as a technique has a number of advantages. The method is able to determine and quantify anions, cations, amines, carbohydrates, organic acids and polar substances in a range of food and drink. Effective at even low concentrations, it is able to detect from minor ingredients and trace contaminants to major components. Importantly, it allows multiple analytes to be determined in the same run, with little or no sample pre-treatment.

A key application of the technique is in the analysis of dairy products for quality control purposes. For example, it can be used to confirm the lactose content of foods labeled “lactose-free” and to check for contaminants in milk such as thiocyanate, perchlorate and melamine. Preparation of dairy products for ion chromatography analysis is normally quite time-consuming and laborious due to the need to perform a protein precipitation step with Carrez reagent. But inline dialysis, as offered by Metrohm, means that protein-containing matrices are automatically removed.

Advantages of Raman spectroscopy in detecting pathogens

A technique that has undergone significant advances in recent years in Raman spectroscopy. In the food industry, this technique allows a rapid method to detect pathogens in food samples during food production. The current gold standard for characterizing pathogens is bacterial culture, but this can take several days, and many bacteria are not in fact culturable. Another alternative approach – polymerase chain reaction (PCR) – is also fast and accurate, but is also sensitive to experimental conditions, and samples may contain substances that inhibit the PCR reaction.

Raman spectroscopy offers the advantage of being able to deliver high-specificity spectra of single cells within seconds in a non-destructive manner. And, although it is possible to apply the technique to cultured bacteria, it does allow this step to be omitted.

This year at Pittcon, a presentation from Steven Zbylut of General Mills will consider the advantages and applications of Raman spectroscopy to the food industry. Zbylut will explain how the technique is particularly suited to detected food adulteration and contamination and explore how its use will continue to grow in future thanks to developments in other technologies and software.

References


Chapter 4 – Case Studies: Beverage Analysis

Beverage analysis is important from both the point of view of product quality and taste, as well as meeting the regulatory requirements in place in many countries. There are many spectroscopic and analytic options available to those needing to perform beverage analysis and many of the leading companies providing devices for these purposes will be in attendance at this year’s Pittcon.

Ion chromatography for water analysis

Drinking water is subject to much regulation and must be routinely tested for contamination and impurities. Ion chromatography can accurately determine the components of water samples, including trace contaminants. One particular advantage is that it can analyze multiple components at the same time from one sample.

Ion chromatography can be used to analyze common ions found in water, such as fluoride, chloride, and bromide, and is used in the US by the Environmental Protection Agency for this purpose.

One highly toxic contaminant hazardous to human health that must be detected in mineral and drinking water is hexavalent chromate, which can make its way into water via environmental pollution. The EU and World Health Organization set the limit value for chromate concentration at 50 µg/L, but there is debate about whether this should be lowered. The state of California have chosen to lower the hexavalent chromate limit to 10 µg in drinking water.

A team from Metrohm, one of the companies exhibiting at this year’s Pittcon, developed a method that they showed could detect chromate at levels as low as 0.02 µg/L, meaning the technology is able to support detection at lower limit values if they were to be imposed by regulators.

Metrohm also offer a fully automated water analysis system, which can assess up to 59 100-ml samples at a time. The system can assess conductivity, pH value, titratable acidity, alkalinity, hardness, and several individual substances such as chloride, without the need for multiple sample preparation.

Laser diffraction to replace sieve analysis in coffee quality control?

While health and hygiene are important concerns for any drinks supplier, analytical methods are also widely used in quality control. One example of this is in the production of ground coffee, where manufacturers need to ensure that the particle size is maintained and the final product is consistent.

A team from Malvern showed that laser diffraction has the potential to replace the traditional method of doing this by sieve analysis. The company, who are on hand at this year’s Pittcon, has produced a funnel sample feeder which they used in association with a Mastersizer 3000 dry powder disperser. This allows the dispersion and measurement of coffee samples up to 130 ml in volume.

The team showed that the device permits laser diffraction of coffee samples with the level of reproducibility required by international standards. Using the set-up, they analyzed two different grades of coffee: one coarse ground and one finely ground. The team put through 15 samples of the two coffee grades, which they were able to do at an average interval of two minutes.

The results showed laser diffraction was able to make a clear distinction between the coarse and fine coffee. Looking at the variation between the 15 different measurements taken for each coffee, it also fell within limits stipulated by ISO13320 (within 3% for the Dv50 and within 5% for the Dv10 and Dv90). Malvern say that the system is easy-to-use and allows for high throughput, which could make it an ideal replacement for sieve analysis in coffee production.

Wine authentication through NMR

The wine industry is one that greatly benefits from the ability to authenticate its products. Bruker has recently introduced a wine-profiling module to its NMR FoodScreener which allows a range of relevant parameters to be measured. The system is able to assign origin for the major wine-producing countries and can also assign region for several parts of France, Italy and Spain. It is also able to detect 22 different grape varieties and a more recent feature is the addition of vintage validation.

Bruker’s system offers both targeted and non-targeted analysis, as the NMR delivers information on targeted parameters but the same spectra obtained for a wine can also be compared with those stored in a database of spectra from authentic wines, allowing for verification of variety, origin and vintage.

Adopting the Coulter principle for beer analysis

Another technique applied to the analysis of alcoholic drinks is the Coulter principle or electrical sensing zone method. It was originally developed in the 1940s to count blood cells but has since been co-opted for many other purposes in life sciences and industry.

One such purpose is to assess particle size during or after the brewing process for beers, in order to evaluate and correct any errors in the production steps. Particle size plays a role in the characteristics of different beers and also affects shelf life. The method can also be used to assess the efficacy of filtration, a process used to clarify beers and make them more stable when subjected to temperature change.

Beckman Coulter, who will be presenting their technology at Pittcon 2017, have shown how their instrument, the Multisizer 3, is able to determine particle size distribution and concentration within beer samples. The method benefits from speed and accuracy and the automated function of the Multisizer 3 also means that results are comparable over time and between locations.

References


Conclusion

Despite the growing number of challenges to food safety, a continuous process of innovation is allowing the emergence of new technologies, or new applications of existing ones, giving us increasing power to face up to these matters.

Recent examples have included the use of NMR to detect the adulteration of olive oil, a widespread problem in imported products, as well as novel applications of mass spectrometry and infrared spectroscopy. Raman spectroscopy is also emerging to have important applications for the rapid detection of foodborne bacteria. And, when it comes to that most vital substance, water, a whole wealth of technologies can be applied to assure its quality and safety, many of which can now be fully automated.

This year’s Pittcon exposition will feature many of the companies who are developing and delivering these devices to the food analysis industry and they will be on hand to present their current lines of products. Companies featured include Bruker, Metrohm, Renishaw, Perkin Elmer and Wyatt Technology.

And to hear about the most up-to-date advances in the industry, head to this year’s symposium, which will feature presentations from leaders in the field on food analysis methods. This year’s topic takes us “beyond mass spectrometry” to hear about some lesser known and emerging techniques using NMR, Raman spectroscopy, DNA barcoding and wireless sensor technology.

For example, a team from GE Global Research will be demonstrating how RF-based sensors can be adapted and applied to a variety of food quality control purposes, and outlining the latest developments in GE’s KemSense technology. In a further presentation, Rachel Gloyer from the UK’s FERA Science Ltd will show how next-generation DNA sequencing has created a path for DNA barcoding in food fraud detection. Gloyer will explain the techniques used FERA, who work on behalf of the UK government, to track bacterial food outbreaks and test food samples using the latest DNA sequencing technology.

Pittcon is the event of the year to hear about the most up-to-date advances, the latest instruments, and innovative technological applications in the field of food analysis. Be there in Chicago in 2017 for all of this and more!