News

The authors of a recent study (here – purchase required) investigated the effect of using different chemometric models to differentiate rice varieties using the same multivariate technique (Raman spectroscopy, also using FT-IR as a comparator) and the same reference sets of authentic rice.  They found a significant difference between method performance depending on the classification model underpinning the chemometrics.  They reported the optimum model to be Supervised Kohonen Map with Multiplicative Scatter Correction (SKM + MSC).  They have proposed a Raman spectroscopy protocol which gives a reliable and rapid point-of-use screening test for rice grain variety.

Photo by Pierre Bamin on Unsplash

Edible poppy seeds may be diluted with poppy seeds that do not meet specifications on alkaloid content (e.g. have not been harvested or washed following specified protocols) or with cheaper species such as sesame or chia.  In a recent proof-of-concept study (here – open access) the authors propose a panel of 47 compounds, primarily alkaloids and their metabolites, whose ratios can be used as analytical markers of sophisticated dilution or adulteration.  Measurement is by LC-ToF.  They compared this favourably with a traditional microscopy approach and validated it with twenty three samples (eight of which were botanically verified) and eight adulterants.

Photo by Wolfgang Hasselmann on Unsplash

Adulteration of goats milk with cows milk is a safety hazard (to allergenic consumers) as well as an economic risk.

The detection of caseins by mass spectrometry requires the selection of suitable characteristic peptides. A recent paper (here – open access) reported developing and optimising a MALDI-TOF MS method to detect the three most representative specific peptides of caseins in cow milk. It was found that 2,5-dihydroxybenzoic acid (DHB) was a more suitable MALDI matrix than α-cyano-4-hydroxycinnamic acid (CHCA), giving an LoD of 0.1 mg/L for α, β-casein.  A protocol was developed and proven to detect adulteration of goats milk with cows milk at 1% or more.  The method was applied to Chinese market samples of five brands of commercial goat milk.  Specific peptides of bovine casein were detected in four of them.

The authors conclude that the method is reliable, high throughput, rapid, has simple preprocessing, and can be a powerful tool for prewarning of dairy allergens.

Photo by Eiliv Aceron on Unsplash

The latest blog from the Michegan State University’s Food Fraud Prevention Think Tank (here) summarises a very useful self-assessment checklist for food businesses to assess whether they are adequately assessing their fraud vulnerability.  It recommends repeating this gap analysis at least annually.  The blog also includes a more specific self-assessment checklist for businesses that claim organic certification.

The EC Joint Research Centre (JRC) have published their monthly collation of global food fraud media and official control reports (here).  FAN member Bruno Sechet, director of Integralim food safety consultancy, has kindly formatted the data into the attached infographic.

The authors of a recent report (here – open access) have collated and indexed nearly 2000 official reports and media reports of meat fraud in China over a 10-year period.  They have data-mined insight on the most frequent types of fraud (e.g. adulteration, counterfeiting), affected types and cuts of meat, and most affected provinces of China.  The results are presented in tabular format.

Access to their detailed database is available on request.

1% is widely used as a compliance threshold for undeclared meat species.  It is based on empirical studies which concluded that adventitious cross-contamination is unlikely to occur above 1% if cleaning protocols, typical of meat industry best practice, are used on cutting and processing equipment.

 A recent study (here – purchase required) challenges this assumption.  The authors studied cleaning protocols and adventitious cross-contamination of pork into ground beef within small-scale meat processors and butchers shops in Quebec, Canada.  They recognise that full strip-down and cleaning of grinders is impractical in these situations and is not required by local hygiene regulations.  Therefore, in practice, they found that cross-contamination of pork in ground beef can often be above 1% when businesses are operating legally and in full compliance with hygiene rules.  They recommend not using 1% as a fraud compliance threshold in this context as it could expose small-scale processors to unwarranted sanctions.

Photo by Kyle Mackie on Unsplash

A link to the 2016 FAO Imported Food Control manual has been added to the FAN "Policy" resources.

This is one of the series of FAO manuals describing how to set up legal frameworks and testing infrastructure for a variety of food safety issues.  Although not specifically fraud-focussed, the Imported Food Control manual does include adulteration as one of the risk factors and has a number of useful pointers and checklists when setting up a national import checks framework.

It is difficult to verify meat species in highly-processed foods that have insufficient intact DNA.  One approach is to test and interpret protein patterns.  This is far from straightforward.

A recent paper (here – purchase required) describes an advancement.  The authors used gel-eluted liquid fraction entrapment electrophoresis (GELFrEE) to separate heat-stable peptide markers, rather than proteins, prior to measurement by MALDI-ToF-MS.  They report this “peptideomics” as easier to interpret than proteomics. GELFrEE fractionation has been previously used for microbial proteins and clinical samples but rarely applied to meat speciation.  It is analogous to SDS-PAGE but protein/peptide fraction are collected in the solution phase at the end of the run. It enables large sample loadings (max. 5.0 mg/strip) improving sensitivity for low-concentration markers with a dynamic range from 3.5-500 kDa and is suitable for automation.  The authors discriminated pork/waterbuffalo in heat-processed mixes down to 0.5% w/w.

Photo by Alexander Schimmeck on Unsplash

If you are a food business and have a measurement issue that you'd like to resolve then why not apply and see if you can get the nation's top measurement laboratories on the case?

Over 90% of businesses completing an A4I Project have reported business growth due to increased productivity, and over 60% saw their competitiveness improved in their markets.

You can find out more about how we support UK
companies through the A4I programme here, and for information about the Programme and how to apply, please visit A4I.info.                                             
Start your application here!                                        
Competition opened on Monday 24 April

Monofloral honeys are generally defined by their pollen count; to be labelled as monofloral, the honey must contain a minimum proportion of pollen from the named flora.  These minimum legal criteria are not consistent between different EU Member States. Pollen identification by microscopy is also becoming a rarer skill amongst analysts. 

In this proof of concept study (here – open access) the authors propose an alternative approach using the pattern of polyphenols as a marker of botanical origin.  They measured a panel of polyphenols by UPLC-MSMS and used Principal Component Analysis to classify them for Hungarian acacia honeys.  The results not only correlated with botanical but also with regional origin.  The variation was driven by three key polyphenols; caffeic acid, 4-hydroxybenzoic acid and p-coumaric acid.

Photo by Wolfgang Hasselmann on Unsplash

The USDA published (here) their new rules on verification and enforcement of Organic certification in January this year.  We are now into the implementation period.  Businesses must comply by 19 March 2024.  US retailers are starting to map out exactly what the new rules mean for them, typified by an article in last week’s trade press (here). There are also requirements for food businesses that export Organic products to the US, with a mandatory electronic import certificate and the need for all agents in the supply chain to be certified.  The new procedures should strengthen traceability and reduce the opportunity for fraud.

Photo by Tingey Injury Law Firm on Unsplash

Shrimp is processed into culinary powder in many countries.  Only the abdomen of mature shrimp should be included. It can be adulterated with the thorax (head), other shrimp parts (including hazardous sharps), or illegally caught immature shrimps.

Researchers from Kwame Nkrumah University of Science and Technology, Ghana, have published (link – purchase required) a study demonstrating the use of handheld near infrared spectroscopy (NIR) to detect adulteration. They developed models using tandem chemometrics and multiple spectral preprocessing with linear discriminant analysis.  They classified shrimp powder adulterated with milled immature shrimps at 0, 5, 10, 20, 30, 40, 50, and 100% w/w with an average cross-validation accuracy of 93%, and achieved an accuracy of 98% for equivalent classification of milled shrimp head in shrimp powder. They used the model in the field for some preliminary surveillance testing and confirmed suspected shrimp powder adulteration in Ghanaian markets.

Photo by Indivar Kaushik on Unsplash

A recent systematic review (here – open access) covers DNA methods published 2015-2022 to detect game and unusual meat species.  It includes conventional RT-PCR, other amplification protocols and full sequencing.  The review is organised both by target species and by test method.  The authors make the point that there are tests published somewhere for almost every species but that when it comes down to practice most testing relies on RT-PCR for a limited panel of targeted species.  In Europe, particularly, there is still a strong emphasis on testing for undeclared horsemeat.  The most common “unusual” species included in targeted tests are buffalo, camel, deer, donkey, fox, mink, horse, rabbit, wild boar and yak.

Photo by Quaritsch Photography on Unsplash

Global consumption of quinoa flour has increased in recent years. It is a relatively high value product and potential adulterants (flours of cheaper grains or seeds) are visually identical. Adulteration is a risk. In this study (here – open access) portable hyperspectral imaging in the visible near-infrared (VNIR) spectral range (400–1000 nm) was applied as a rapid tool. The concept was proven using quinoa flour adulterated with wheat, rice, soybean, and corn in the range of 0–98% with 2% increments. Partial least squares regression (PLSR) models were developed, and the best discriminatory model selected. The model was improved by selecting only 13 wavelengths, rather than using the full spectrum, using bootstrapping soft shrinkage. A visualization map was also generated to predict the level of quinoa in the adulterated samples. The study proved the concept of using rapid and portable non-destructive VNIR as a screening tool for quinoa flour adulteration.

Photo cropped from HowToGym on Unsplash

Defra report FA0175 has been added to the links in the Research Outputs resources on our website.  This report gives an inventory of different tools and methods to manage the risk of food fraud and compares them with the factors that drive fraud.  Many FAN members contributed to this study.

https://www.foodauthenticity.global/research

(projects are tabulated in numerical order)

Digital systems and tools are evolving at a rapid pace so some of the specifics in the report are already out of date.  But the fundamentals remain pertinent.  The best food businesses and regulators employ a range of tools, covering everything from people culture to criminal justice records to ingredient specification databases.  The common denominator is a willingness to share information.

John Spink addressed FAN's most recent laboratory Centres of Expertise meeting on this topic and has kindly agreed to make a recording of his presentation available to FAN members.  Click on the image below to watch the recording.

John is a global thought leader on the subject.  This 25 minute talk explores how food companies should decide when and what to test, how testing fits into a holistic supply chain assurance strategy, and how laboratories and food companies can form strategic partnerships by understanding each others' issues and priorities.  It is well worth a watch for both laboratories and their customers.

In a recent column in Food Safety Magazine (free, but sign-up required), supply chain experts John Keogh,  Steve Simske and Louise Manning review the current state of the art in food supply traceability, the drivers for traceability improvement, and take a look into the future.  They discuss the increasing need for claims verification, particularly with regard to ethical production standards, as well as the need for rapid traceability in the event of a recall or safety alert relating to an ingredient.  Digitised traceability is a rapidly evolving field, and this article gives pointers to recommended best practice and guidance documents.

Photo by NASA on Unsplash

Thank you again to our member Bruno Sechet for formatting the JRC monthly summary of fraud reports as a graphic and allowing us to share it with you.

The full March 2023 summary from JRC is available here.  We encourage you to sign up for e-mail notifications when these are published.  They are a valuable free resource.

Three different articles have been published in the past month relating to analytical methods to detect fraudulent claims of Halal production.  Each method can be used to disprove a specific aspect of the Halal claim.

One verification requirement is a quick and obvious test for economically motivated adulteration with pork.  Researchers at South-Central Minzu University, China (link – purchase required) used isothermal amplification with CRISPR/Cas12a cleavage to target and measure a porcine-specific gene in nuclear DNA.  Use of nuclear DNA gave a linear calibration in a 25-minute point-of-use test allowing quantitation down to 5% of added pork.

Halal production also mandates the segregation of pork to avoid cross-contamination.  Detection methods are also needed that are sensitive enough to identify segregation failure.  Researchers from the Tamil Nadu Veterinary and Animal Sciences University (link – open access) reported a novel isothermal amplification technique, Polymerase Spiral Reaction, of mitochondrial DNA.  They reported good sensitivity, with a 65-minute point-of-use assay able to detect contamination down to 0.5% of pork in beef.

A third aspect is dilution with meat which has not been Halal slaughtered.  A perennial problem in many countries is the inclusion of meat from animals which died prior to their planned slaughter; termed “casualty animals” in Europe or “carrion meat” (or “tiren”)  in SE Asia.  A team from the National Research and Innovation Agency, Indonesia (Link – purchase required) have published a review of chemical, biochemical and physical markers that can be used to distinguish carrion meat from slaughtered meat. A panel of 14 parameters were selected that could form the basis of an Indonesian national standard.  They include malachite green-H2O2, correlated protein with meat texture, peroxiredoxin-6, blood biochemistry, blood pH, capacitance value, meat colour, Warner-Bratzler shear force, blood loss variation, meat quality, water holding capacity (WHC), resistance value, E. coli load, and coliform load.

 Photo by Syed F Hashemi on Unsplash