Most researchers conclude that there is too little intact DNA in gelatin for traditional PCR to be applicable as a species authentication method. A recent paper (here – open access) published in the pharmaceutical press is unusual in reporting success of the approach. The authors used primers that they had previously developed in-house. They tested the gelatin in pharmaceutical capsules for the presence of porcine DNA, in order to verify Halal medicine claims. They validated the method using one provenant beef and one pork gelatin capsule then piloted the method on four market samples, detecting porcine DNA in three of them.
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A recent study (here – open access) reported the development and validation of a duplex real-time polymerase chain reaction (qPCR) assay for simultaneous identification of sheep and goat meat. Amplicons were detected using high-resolution melt analysis (HRMA). Species-specific amplicons with melting temperature of 78 °C for goat and 80 °C for sheep (with associated standard errors) were identified. The assay was optimized for basic PCR parameters and the HRMA detection was standardized based on melt curve shape, colour and inflexion points. The absolute limit of detection (LODabs) and limit of quantification (LOQ) of the assay were found to be 0.39 ng and 0.78 ng of target DNA respectively. A sensitivity of 0.1% (w/w of meat) was obtained for both sheep and goat meat. The linearity and efficiency were evaluated in both simplex and duplex assays. The authors concluded that this closed-tube qPCR-HRMA method can be a rapid and sensitive detection technique for meat speciation.
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Mānuka honey authentication is currently based on four markers (3-phenyllactic acid, 2′-methoxyacetophenone, 2-methoxybenzoic acid, and 4-hydroxyphenyllactic acid) which must be present at minimum concentrations. Sophisticated fraudsters could augment these markers to mask dilution or substitution with cheaper honey. A recent study (here – open access) used chemometrics to propose 19 other markers which are unique to manuka. Nine of these are reported for the first time. The authors propose that this wider panel of markers, measured by LC-MS, would make fraudulent masking of dilution much more difficult.
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Police have broken up a sophisticated and large scale food supply network, based in Lithuania but believed to also reach into Italy and Germany. The criminal gangs purchased date-expired, or near-expiry, food then used sophisticated equipment to remove the date codes and re-label with a new date before selling on. It appears to have been "best before" products rather than "use by", so primarily a risk to food quality rather than consumer safety. There are no reports of consumer illness
News report here
A new palm oil traceability system is being launched in Ghana. The system, developed last year in collaboration with Solidaridad, is a collaboration between the Ghana FDA and the Artisanal Palm Oil Millers and Outgrowers Association. It is designed to address concerns raised by a recent FDA survey which revealed palm oil adulteration at 23% incidence with Sudan IV Dye still being used to mask substitution. The FDA will implement a licensing system for palm oil processors, with the association issuing traceability QR codes on packaged palm oil. The Traceability and Compliance Data Authority (TCDA) will monitor all palm oil transportation within the market through the issuance of waybills. Registered individuals will be issued ID cards embedded with bar codes, which will be frequently scanned for tracing purposes. A full report is here.
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Butcher issued with suspended sentence in court.
A butcher who was found guilty in court in 2021 for selling poor quality chicken has been issued with a suspended prison sentence and told he can’t work in the food industry anymore.
During a routine inspection of Barking Halal Meat & Fish in August 2019, officers from Barking and Dagenham Council found a number of breaches of food hygiene rules which presented a risk to customers and their health.
The owner of the business, Mr Azar Irshad was initially summoned to court in September 2021, however he failed to attend. In his absence, the judge fined the company £40,000 plus £5,075 in costs to be paid to Barking and Dagenham Council and a Victim Surcharge of £170. In addition, a warrant had been issued for Mr Irshad’s arrest since February 2020.
During the inspection in 2018, council officers were offered bribes and fake receipts were also provided in an attempt to legitimise the supply chain.
Police finally caught up with Mr Irshad and he attended Snaresbrook Crown Court on Friday 24 March where he was sentenced to prison for 39 weeks suspended for 18 months, 200 hours of unpaid work and costs of £2,400. He also received a Criminal Behaviour Order banning him from working in the food industry.
Read full article here.
This critical review (here – purchase required) discusses the strengths and weaknesses of current methods that are routinely used within the food industry for meat species authentication. The authors classify methods as protein-based, metabolite-based, or nucleic acid-based. They stress that, irrespective of the method, the key factor is the choice of appropriate markers. They conclude by discussing likely future trends.
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The authors of this study (here - open access) describe a novel composite thin film based on rhodamine B encapsulated into MOF-5 (Metal Organic Frameworks) as a fluorescence sensor for the real-time verification of the freshness of chilled pork. The composite film can adsorb and respond to the volatile amines produced during the deterioration of pork. The fluorescence intensity of RhB decreased with decreasing freshness. A quantitative model was built using 30 reference samples to predict the freshness indicator (total volatile base nitrogen) as defined by Chinese national standard GB 5009.228-2016. The biosensor compared favourably to the official Kjeldahl method. A qualitative model established by the partial least squares discriminant analysis (PLS-DA) algorithm was able to accurately classify pork samples as fresh, acceptable or spoiled. The article is part of a special issue (here – open access) of Biosensors on rapid non-destructive biosensors for food analysis.
Registration for this hybrid course at University of Parma, Italy, is open (here) until 2 June. It is aimed at Parma PhDs but open to others to sign up. The course promises to bring together the most advanced technical skills from STEM and the methodological approach from social sciences, also considering the major certification schemes. Particular attention will be paid to communication to consumers. It runs from 4 September – 20 October, including in-person at Parma from 25-27 September. The course is subsidised by the European Commission, with delegates paying a 100Euro fee.
This incident was reported in the Spanish press (here). 40,000 Euro-worth of almonds were rejected at port of entry due to high aflatoxin tests. The importer certified they had sent the load for incineration. In fact, they tried to divert them back into the market. The fraud was revealed by mass-balance check. The importer had shelled the almonds and only incinerated the shells. The weight rejected at port and the weight incinerated did not tally.
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The Michigan State University’s Food Fraud Prevention Academy have launched their latest free Massive Open Online Course (MOOC) (link). The target delegates are both procurement professionals and food safety managers. The course aims to foster a collaborative approach between the two disciplines. It includes food fraud-specific supply chain disruptions, vulnerability assessments, and practical guidance on how to fulfil GFSI requirements, for example with a template for supplier self-assessment questionnaires. This new course is one of a suite of MOOCs designed by Professor John Spink, a member of FAN’s steering board.
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The authors of a recent article (here – purchase required) report a novel approach to testing vegetable oil species and to identifying adulteration of sesame oil with soyabean oil. They used excitation-emission matrix (EEM) fluorescence spectroscopy to generate multivariate data sets then tested three chemometric methods to build classification models. Two of the models gave Total Recognition Rates of 100% when presented with unknown samples of pure vegetable oils and of adulterated sesame oil (the lowest % adulteration tested is not specified in the abstract). The authors conclude that their model can quantify the % adulteration of sesame oil with soyabean oil.
A recent article (here – open access) gives an overview of non-targeted approaches to authenticity screening. It is written at a level of technical detail useful to laboratory analysts or technically-informed industry customers. It discusses spectroscopic techniques (NMR, IR and MS) and the use of machine learning to derive classification sets from reference sample sets. It focusses, particularly, on how to deal with the statistical probability of a subsequent false-accept or a false-reject verdict on a test sample based upon an incorrect or uncertain (“grey”) classification.
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A comprehensive review of lipid characterisation in nuts and oily fruits (here – open access) includes a section reviewing recent “lipidomics” publications for authenticating premium oils. The scope includes nut oils, seed oils, olive and avocado oils, and geographic fingerprinting of the origin of almond or peanut oil.
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The annual “State of Counterfeiting in India” report has been published for 2022 (here) by the Authentication Solutions Providers Association (ASPA). As well as counterfeit spirits, it highlights counterfeit agrochemicals as a particular concern and estimates the incidence as 30%. Sub-quality counterfeit agrochemicals can lead to food safety risks from unexpected pesticide residues, metabolites or excipients. Crops grown in India, and in neighbouring countries which may import Indian agrochemicals, are exported and eaten around the world.
Goat meat has a price premium over sheep meat in many countries. They are visually very similar. The authors of this study (here – purchase required) report a novel DNA test that does not require amplification using heating cycles (PCR). This makes it suitable for field-based testing. They have applied the isothermal polymerase spiral reaction (PSR) assay to goatmeat for the first time. Their assay is targeted against the mitochondrial DNA and can be read based on a visual colour change after the addition of SYBR Green I dye to the amplified product. The possibility of cross-amplification was ruled out by testing other meat species (buffalo, cattle, chicken, pig, sheep, and ostrich). PSR could be undertaken at 62 °C for 60 min with the limit of detection of 0.5 ng DNA (approximately equivalent to 0.1% w/w of meat). The PSR was found efficient in the detection of not only raw meat but also meat heated to 121 °C for 30 min. When combined with the alkaline lysis method of DNA extraction, the goat-specific PSR takes 90 min of sample analysis time.
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Coffee beans from different regions and of different species have different commercial values. A recent paper (here – open access) reported a method to differentiate green beans from different species (Arabica vs Rustica) and harvested from different regions of Vietnam. The test technique was ultraviolet–visible (UV–VIS) spectroscopy combined with the Partial Least Squares with Discriminant Analysis (PLS–DA) model. Spectra of 147 authenticated samples were used to build prediction models. The authors reported that accuracy of species differentiation was 100%. Accuracy of regional differentiation varied from 88% to 96%. They concluded that the results show the potential of UV–VIS spectroscopy databases to verify the authenticity of green coffee beans.
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The EU and UK legal definition of honey is specifically the product of Apis mellifera (Western Honey Bee). It excludes the product of Apis cerana (Asian Honey Bee). The authors of a recent study (here – purchase required) used multivariate statistical analysis on the GC-MS of fatty acids to identify two fatty acids (8-hydroxyoctanoic acid and 3,10-dihydroxydecanoic acid) that can be used as markers to differentiate honeys from the two different bee species.
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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.
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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.
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