In regions where clarified dairy fat (ghee) is a staple food, the potential for adulteration with palm oil (solid vegetable fat) is a continual concern.  Analytical differentiation can be difficult.

In this study (open access) the authors experimentally compared and contrasted a range of analytical techniques that have been proposed for identifying palm oil mixed into ghee at levels down to 5 – 10% (generally considered the lower limit for economically motivated adulteration). 

They concluded that  both Butyro refractometer readings and iodine value analysis were not as efficient in detecting adulteration at lower level. Reichert-Meissl value analysis alone was not able to draw a conclusion regarding the purity of ghee. However, the Kirshner value analysis could be an effective parameter to detect adulteration of palm oil in ghee down to 5%. 2,2-Diphenyl-1-picrylhydrazy and ferric chloride-based chromogenic tests were very effective to detect the presence of palm oil in milk fat or ghee rapidly; thus, these tests could be used in field conditions. The use of triglyceride analysis (S-value) and plant sterol detection offered a comprehensive laboratory-based confirmation to detect palm oil adulteration in ghee at 5% levels.

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

FSA-funded project: Review of current and emerging analytical methods for the testing of oil for authenticity (Project FS900520)

With funding from the UK Food Standards Agency, Fera Science Limited (Fera) in York, UK is currently undertaking a project to review the current and emerging analytical methods for testing edible oils and support the further development of analytical methods which will underpin and uphold the authenticity of edible oils in the supply chain. 

As part of the project’s evidence gathering, Fera would like to invite parties involved in sourcing, processing, and/or testing edible oils to participate in an online questionnaire. 

The fundamental mission of the FSA is food you can trust. The FSA strategy sets out FSA’s vision to ensure that the UK food system is safe, and that food is what it says it is. This involves building scientific capability in Public Analyst (PA) Official Laboratories (OLs) and working with Defra’s food authenticity programme to conduct research and development for analytical methods. Suitable analytical methods are required to ensure that food is what it says it is and to manage risk around food authenticity.

 As key stakeholders, your insight will help to inform FSA regarding issues in oil authenticity and future-proofed analytical tools to support both industry and regulators, while maintaining consumer confidence in our food. 

 Your participation will be very much appreciated and your views and insight will be invaluable to the project aims.

 A summary of key findings from the questionnaire will be included in the final report, but no sensitive information will be published.

Please complete the questionnaire here. If you have any questions, please contact info@fera.co.uk.

Your kind participation will be very much appreciated and your views and insight will be invaluable to the project aims.

Photo by Stephanie Sarlos on Unsplash

The International Fruit and Vegetable Juice Association (IFU) is to make IFU methods freely accessible to official laboratories in future.

Interested parties should contact the IFU Secretariat; the contact person is Aintzane Esturo (aintzane@ifu-fruitjuice.com).

Researchers have evaluated recent developments in nutrition science, analytical technology and the continuing evolution of statutory regulations and conclude that most current international reference methods are no longer fit-for-purpose to accurately determine vitamin content in foods and food supplements.

They recommend that new and/or updated reference methods and regulatory standards should be considered for the analysis of vitamins A, D, E, K, B₁, B₂, B_3, B₅, B₆, B₇, B₉, B₁₂, C and carotenoids in foods and food supplements.

They also state that this area of nutrients may benefit from globally harmonised definitions specifying what compounds to include or exclude for analysis, and applicable bioactivity factors. 

Read open access paper: https://doi.org/10.1016/j.foodchem.2024.139383

Photo by Diana Polekhina on Unsplash

Pictured above is Bhavna Parmar of the UK Food Standards Agency with Anne Bridges of AACC International.

The Codex Committee on Methods of Analysis and Sampling (CCMAS) held its 40th Session in Budapest, Hungary, from 27 to 31 May 2019. The Session was attended by 49 Member countries and 1 Member organization and 12 observer organisations.

Selvarani Elahi, representing the UK Government Chemist, attended as part of the UK delegation together with colleagues from the Food Standards Agency and the Association of Public Analysts.

CCMAS considers methods of analysis for Codex standards and testing in relation to international food trade. CCMAS 40 discussed analytical methods for nutritional metals, acid value and free fatty acids in palm oil, milk and milk product commodities, 'gluten free' labelling in products containing cereals, pulses and legumes, and herbs & species. The meeting also received updates from working groups on the revision of three substantive Codex documents: general standard for methods of analysis and sampling, guidelines on measurement uncertainty and guidelines on sampling. Work on these documents continues in order to reach global consensus.

As there is increasing interest in food integrity and food authenticity at Codex, the poster on the Food Authenticity Network attracted attention from delegates. Follow-up discussions are planned with member countries on creating ‘country-specific’ pages on the Food Authenticity Network for their countries in order to create a truly global network. Discussions will also continue with the food industry and observer organisations looking to support the work of the Network.

If you would like further information on supporting the Network, please contact us on Secretary@foodauthenticity.uk.

The Food Authenticity Network is mentioned in the meeting report, which is available from the Codex Alimentarius website.

IFST has re-written its “Food authenticity testing” Information Statement and split it into two parts:

• Food authenticity testing part 1: The role of analysis, which now covers the role of analytical testing within the context of an overall supply chain assurance strategy.

Analytical testing is a valuable tool in the armoury to assure food authenticity but cannot be used to identify every type of food fraud.  It is only one part of an overall strategy to mitigate fraud risk.

Many modern tests are based upon comparing a pattern of measured values in the test sample with patterns from a database of authentic samples. Interpretation is highly dependent on the robustness of the database, and whether it includes all possible authentic variables and sample types. This information may not be released by the laboratory.  Interpretation of results is rarely clear-cut, and analytical results are often used to inform and target further investigation (such as unannounced audits or mass-balance checks) rather than for making a compliance decision.

This paper describes where testing can and cannot be used, and highlights generic issues relating to interpreting food authenticity testing results.

• Food authenticity testing part 2: Analytical techniques, which gives describes specific analytical techniques, their applications, strengths and weaknesses.

This paper describes the principles, different configurations, applications, strengths and limitations of some of the more common analytical techniques used in food authenticity testing:
• Mass spectrometry
• Stable isotope mass spectrometry
• DNA analysis
• Nuclear magnetic resonance spectrometry
• Spectroscopy.

Generic strengths and limitations of food authenticity test methods, particularly those relating to methods comparing against reference databases of authentic samples, are discussed in “Food authenticity testing: The role of analysis”. It also describes the difference between targeted and untargeted analysis.

A new discussion has been posted on the 2017 Code of Practice on Basmati Rice asking for views on the need for updated methods of analysis.

Please visit our discussion forum and have your say.