News

In common with most jurisdictions, India has regulatory analytical criteria for authentic honey.  This includes various stable isotope ratios.

In this study (open access) the researchers set out to construct an analytical database of fully traceable authentic honeys in order to verify the criteria set by the Food Safety and Standards Authority of India.

They collected 98 authentic samples (covering 19 botanical sources, 42% multifloral and 58% monofloral).  They covered 17 states and provinces.  Sample were from collection centres of the All-India Coordinated Research Project on Honey Bees and Pollinators (AICRP, HB&P), under the auspices of the Indian Council of Agricultural Research (ICAR).   In addition, beekeepers registered with the National Bee Board (NBB) were also identified for sample collection. All samples were fully traceable.

The researchers generated a database of stable carbon isotope ratios (¹³C/¹²C) by Elemental Analyzer/Liquid Chromatography–Isotopic Ratio Mass Spectrometry (EA/LC-IRMS). The samples were analyzed for the parameters δ¹³C_Honey(δ¹³C_H), δ¹³C_Protein(δ¹³C_P), δ¹³C individual sugars, ∆δ¹³C_{Protein-Honey}(δ¹³C_P-H), C4 sugar, ∆δ¹³C_{Fructose-Glucose}(δ¹³C_Fru-Glu), ∆δ¹³C_max, and foreign oligosaccharides as per the official methods of analysis of the Association of Official Analytical Chemists (AOAC 998.12) and the FSSAI.

The results were evaluated against the published literature and Indian regulatory criteria for authentic honey. The δ¹³C value for honey (δ¹³C_H) ranged from −22.07 to −29.02‰. It was found that 94% of samples met the criteria for Δδ¹³C_P-H (≥−1.0‰), Δδ¹³C_Fru-Glu (±1.0‰), and C4 sugar content (7% maximum), with negative C4 sugar values treated as 0% as prescribed by the AOAC method.  86% of samples met the accepted foreign oligosaccharide criteria (maximum 0.7% peak area).

They conclude that the data of this study provide scientific backing for these four parameters as per the FSSAI regulation. However, the non-compliance of a high number (47%) of authentic honey samples for Δδ¹³C_max (±2.1‰) compels further systematic investigation with a special focus on bee feeding practices. Further, they found that honey samples with a Δδ¹³C_P-H greater than +1‰ and a C4 sugar content more negative than −7% also did not comply with the Δδ¹³C_max criteria. They suggest that Δδ¹³C_P-H values (>+1‰ equivalent to C4 sugar < −7%) could be an indicator of C3 adulteration to some extent.

In this paper (open access) the authors developed and validated a novel sample introduction mechanism (a new configuration of Solution Glow Cathode Discharge, SGCD) to enable heated and diluted honey to be directly analysed by Optical Emission Spectroscopy (OES).  This provided a relatively low-cost and bespoke platform for the routine testing of trace metals in honey.

They measured the concentrations of five metals – Na, K, Rb, Mg and Ca – in a reference set of authentic honeys and honeys adulterated with syrups.  The paper concentrates more on the analytical technique validation than the reference database and so it is unclear how all the reference samples were sourced and prepared, and two reference results were removed from the dataset as unexplained outliers.  Nonetheless, the authors present multivariate statistics showing that the metal profile can be used as an indicator of adulteration, with syrup-adulterated honey having higher Na content and “natural” honeys having higher K, Mg and Ca content.

This could form the basis of another classification technique which, whilst being a long way from definitive, could add to that analytical arsenal in a weight-of-evidence approach to determining honey authenticity.

Further to the review of methods used in the EU co-ordinated survey of honey collected 2021-22 (“From the Hives” survey) – see previous blog here:

The Joint Research Centre of the European Commission have now published (open access) more details of some of the test methods used and results interpretation.  This publication relates particularly to the two qualitative Liquid Chromatography–High-Resolution Mass Spectrometry (LC-HRMS) methods that were developed to detect mannose (Man), difructose anhydride III (DFA III), 2-acetylfuran-3-glucopyranoside (AFGP), and oligo-/polysaccharides with degrees of polymerization (DPs) of 6 to 11.

The presence of mannose and unusual oligo-/polysaccharides was the main reason that many of the samples were flagged as “suspicious” in the previously published report.

There has been a lot posted recently about honey authenticity and test methods.  This blog from the FSA pulls it all together in one concise and systematic page.  It includes

• Honey sampling guidelines
• The weight of evidence approach to interpreting test results
• The UK AMWG review of the EU “From the Hives” report
• New testing methods developed under FSA-funded research

The results of the EC 2021-2022 honey sampling and analysis co-ordinated action, following the  From the Hives report, were concerning.  This 2023 report concluded that all 10 of the sampled honeys imported from the UK were “suspicious”. 

This finding prompted further investigation by the UK Department of Environment, Food and Rural Affairs (Defra).

Defra have now published an independent expert review into the analytical methods used in the survey.  There is a lot of technical content in the review.  It re-emphasises that no single honey authenticity test is likely to be definitive, and that a weight of evidence approach should be used with some tests being weighted higher than others.  When the total weight of evidence is not strong then phrasing such as “warrants further investigation” would be a fairer conclusion than “suspicious”.

One specific learning from the review is that laboratories must take care with the selection of authenticity markers, depending on the analytical question being asked.  The example given is oligosaccharides.  Some of these markers are known to vary between honey that has had moisture mechanically removed compared to honey that has not.  Moisture removal may be a production necessity (in humid climates where honey will not evaporate naturally) or a commercial choice to speed the harvest cycle (as is commonly used in China).  Moisture-removed honey is common within UK blends of Chinese origin honeys  but is not permitted in some EU countries.  Thus a test based on oligosaccharide markers could differentiate UK honey from EU for reasons that are already understood.  It might not provide any new insight, for example, on sugar or syrup adulteration.

Photo by Art Rachen on Unsplash

There is no single definitive test for dilution of honey with foreign sugar syrups.  An untargeted test, often used to contribute to an analytical weight of evidence, is proton NMR followed by chemometric pattern recognition based on variations in the sugars profile.  One disadvantage of this technique is a lack of sensitivity. 

LCMS is a more sensitive technique and could – in principle – be used in a similar untargeted manner to drive pattern recognition statistics based on the sugar profiles of a database of reference honeys.  The limiting factor has been the computing power that would be needed to “re-set” the database each time a new chromatographic peak is measured or data from different chromatographic systems are combined. (this is why untargeted LCMS is often used in authenticity testing as a 1-off development tool to identify marker compounds, which are then used as the basis for a more routine targeted test, rather than being used as a routine untargeted test).

In this paper (open access), the authors resolved the computing power limitation by using their Bucketing of Untargeted LC-MS Spectra (BOULS) data processing approach which they have previously published.  They demonstrated that untargeted LCMS testing (combining data from different systems, HILIC column with MS in both positive and negative ionisation mode) could discriminate a range of adulterated honeys (rice, beet and high-fructose corn syrups added at 5% to a reference set of 34 North German honeys) from their unadulterated counterparts.

As is the case with all untargeted analytical techniques, the key to using this method routinely would be building a robust reference database of verified authentic honeys that is fully representative of all types and origins on the market.

Photo by Roberta Sorge on Unsplash

Testing for honey authenticity often requires a panel of different analytical approaches, none of which is conclusive but each giving an increasing degree of suspicion.  Some of these approaches involve high cost specialist equipment and bespoke reference databases.

In this paper (purchase required) the authors propose a panel of three tests using relatively cheap and accessible equipment.  They developed a new high-performance liquid chromatography diode array detection (HPLC-DAD) method for the precise quantification of HMF, and coupled this with analysis of glucose, fructose, saccharose, and maltose using a HPLC with refractive index detection (HPLC-RI) plus diastase activity (DA) using the established Schade method.

They applied their approach to 65 commercial Spanish honey samples, reporting significant compliance with EU regulatory standards, yet also uncovering some suspicions of adulteration.

Photo by Roberta Sorge on Unsplash

This white paper is from the Institute of International and European Affairs, a non-profit charity that is Ireland’s leading international affairs think tank.

The paper tracks the suspicions of honey fraud and subsequent investigations and surveillance monitoring plans over the past decade, leading up to the EU legislation changes in the Breakfast Directive.  The paper makes the case that without this large-scale co-ordinated action and evidence-gathering, the possibility of wide scale fraud might never have been taken sufficiently seriously. It reviews the effectiveness of the current EU regulations and international cooperation efforts that are designed to detect and prevent honey adulteration and asks what technological and legislative improvements can be deployed to protect consumers and support EU honey producers.  It concludes by looking to the future and how honey fraud might be tackled on a local, national, and international level

Abstract

Highlights

The European Parliament and Council agreed to review and strengthen the existing marketing standards applicable to honey, fruit juices, jams and milk. The so-called Breakfast Directives lay down common rules on the composition, sales names, labelling and presentation of these products to ensure their free movement within the internal market and help consumers make informed choices.

The revised Directives agreed upon by the co-legislators will introduce the following changes:

• Mandatory origin labelling for honey:  the countries of origin in honey blends will have to appear on the label in descending order with the percentage share of each origin. Member States will have the flexibility to require percentages for the four largest shares only when they account for more than 50% of the blend. The Commission is empowered by the co-legislators to introduce harmonised methods of analysis to detect honey adulteration with sugar, a uniform methodology to trace the origin of honey and criteria to ascertain that honey is not overheated when sold to the final consumer. A Platform will be set up to advise the Commission on those matters. This will limit fraudulent practices and increase the transparency of the food chain.

• Innovation and market opportunities for fruit juices in line with new consumers demands: Three new categories will become available: ‘reduced-sugar fruit juice‘, ‘reduced-sugar fruit juice from concentrate‘ and ‘concentrated reduced-sugar fruit juice‘. This way consumers can choose a juice with at least 30% less sugars. It will be possible for fruit juices to indicate on their labels that “fruit juices contain only naturally occurring sugars” to clarify that, contrary to fruit nectars, fruit juices cannot by definition contain added sugars – a feature that most of the consumers are not aware of.

• Higher mandatory fruit content in jams: an increase of the minimum fruit content in jams (from 350 to 450 grams per kilo) and in extra-jams (from 450 to 500 grams per kilo) will improve the minimum quality and reduce the sugar content of these products for EU consumers. Member States will be allowed to authorise the term ‘marmalade' as a synonym of ‘jam', to take into account of the name commonly used locally for these products. The term “marmalade” was authorised until now only for citrus jams.

• Simplified labelling for milk: the distinction between ‘evaporated' and ‘condensed' milk will be removed, in line with the Codex Alimentarius standard. Lactose-free dehydrated milk will also be authorised.

The political agreement reached by the European Parliament, Council and Commission is now subject to formal approval by the co-legislators. From entry into force 20 days after publication of the final text, Member States will have 18 months to transpose the new provisions into national law and 6 more months before it applies throughout the European Union.

Read full press release.

Today, the European Commission has published the results of the EU-wide coordinated action “From the Hives” on honey contaminated with sugars.

These investigations aimed to put a stop to operators voluntarily placing contaminated honey onto the EU market and sanction them accordingly if needed. Of the 320 samples taken at EU borders and analysed by the Joint Research Centre (JRC), 147 (46%) were suspected of being non-compliant.

This suspicion rate was considerably higher in comparison to an earlier EU-wide coordinated control plan conducted in 2015-17, where 14% of the analysed samples did not comply with established benchmark criteria to assess honey authenticity.

However, the JRC applied a different set of methods, with improved detection capability, throughout the current exercise, which may explain this contrast.

For more information:

• Q&A (DG SANTE)
• Video (OLAF)
• Press Release (JRC)
• Press release (OLAF)

In response to many questions posted in the chat of the Webinar on the Global Honey Supply Chain that took place on 19 January 2022, the page on the Government Chemist website has been updated with work in progress on honey authenticity:

"This webinar and the consequent e-seminar is part of a suite of activities Defra, FSA, FSS and the Government Chemist are jointly working on to address some of the underpinning scientific issues that have emerged on the subject of honey testing and a number of workstreams are in progress.

Two further e-seminars, which will assist in disseminating information on honey authenticity testing, are in production. These cover using NMR testing for the determination of exogenous sugars in honey and best practice in establishing and curating databases for food authenticity. Work is also underway to develop guidance on applying a weight of evidence approach for food authenticity analysis, to pilot accreditation of non-targeted authenticity testing methods, to improve consistency and confidence in testing and reporting and to explore a data trust framework to share information on the honey supply chain and testing between interested communities. This will be followed by activity to standardise a protocol for the collection of authentic honey samples and to establish a framework for the scrutiny of authenticity databases. We are collaborating with key stakeholders on all these initiatives to secure the best outcome for all.

FSA’s blog on the complexities of honey authenticity, includes links to the recently published Government Chemist independent review of methods for honey authenticity testing and of the analytical reports underpinning recent allegations of honey fraud."

The UK Government Chemist team, hosted at LGC, has recently had two significant scientific papers published in Nature Portfolio Journal, npj-Science of Food, highlighting the increasing complexity of honey authentication.

The papers (Honey authenticity: the opacity of analytical reports - part 1 defining the problem; and part 2, forensic evaluative reporting as a potential solution) are based on a story that appeared in the UK media in November 2020 - Supermarket brands of honey are 'bulked out with cheap sugar syrups made from rice and corn’ – after which the Food Standards Agency asked the Government Chemist to investigate the methods that underpinned the story.

The papers address the complex composition of honey, and how an interpretive system used in forensic science could help to improve evaluation of analytical findings and assessment of their strength, which, in turn, can help to make authentication of honey more robust.

The authors propose the adoption of ‘evaluative reporting’, which would see the acceptance of a formalised ‘likelihood ratio’ (LR) thought process used in forensic science for evaluation of findings and assessment of their strength. In the absence of consensus on techniques for honey authenticity, adoption of evaluative reporting will allow objective assessment, with equity to all, and a better basis to identify and address honey fraud.

Animal origin food products, including fish and seafood, meat and poultry, milk and dairy foods, and other related products play significant roles in human nutrition. However, fraud in this food sector frequently occurs, leading to negative economic impacts on consumers and potential risks to public health and the environment. Therefore, the development of analytical techniques that can rapidly detect fraud and verify the authenticity of such products is of paramount importance.

Traditionally, a wide variety of targeted approaches, such as chemical, chromatographic, molecular, and protein-based techniques, among others, have been frequently used to identify animal species, production methods, provenance, and processing of food products. Although these conventional methods are accurate and reliable, they are destructive, time-consuming, and can only be employed at the laboratory scale. On the contrary, alternative methods based mainly on spectroscopy have emerged in recent years as invaluable tools to overcome most of the limitations associated with
traditional measurements. The number of scientific studies reporting on various authenticity issues investigated by vibrational spectroscopy, nuclear magnetic resonance, and fluorescence spectroscopy has increased substantially over the past few years, indicating the tremendous potential of these techniques in the fight against food fraud.

This manuscript reviews the state-of-the-art research advances since 2015 regarding the use of analytical methods applied to detect fraud in food products of animal origin, with particular attention paid to spectroscopic measurements coupled with chemometric analysis. The opportunities and challenges surrounding the use of spectroscopic techniques and possible future directions are also be discussed.

Read full paper here.

 AOAC International's Food Authenticity Task Force has developed standard method performance requirements (SMPR) for targeted and non-targeted food authenticity methods. SMPR set minimum performance criteria that food authenticity testing methods for milk, honey and olive oil need to fulfil. 

Further information was provided in a recent free-of-charge webinar, which can be viewed on registration.