A message from Dr Liz Barbour, CEO CRC for Honey Bee Products
The ‘Made in Australia’ logo is highly valued and internationally appreciated, as Australia is a country known for a high level of food-safety regulation. Placing a location and visualisation of exactly where that food was produced, as well as securing its passage into any home world-wide, is the new level of expectation for a fine food product.
Honey squarely falls into the category of such a fine food product, with Australian Beekeepers producing some of the rarest wild-collected honeys in the world. Unfortunately, honey can be adulterated, and honey is claimed to be the third most adulterated food product in the world. The challenges this brings to the industry are illustrated from New Zealand data, where it was demonstrated that, internationally, more ‘New Zealand Manuka honey’ was sold than actually produced.
Honey adulteration takes many forms. The two main approaches identified in news headlines are feeding honey bees with a sugar solution to substitute nectar for honey production; and the addition of bioactive ingredients or sugar solutions to the honey itself. In times of nectar resource paucity, honey bees indeed need to be fed sugar solutions to ensure colony survival, and the common sense approach for a beekeeper would be to leave this food resource for the honey bees. In the face of relentless drought and bushfire in 2020, some Queensland and New South Wales beekeepers had to resort to sugar feeding to keep their bees alive in order to meet agriculture pollination demand for the upcoming spring season. For those beekeepers, honey harvesting will not be an option, as honey made from sugar-fed bees does not meet the internationally accepted definition of honey.
The second form of adulteration is the deliberate addition of substances to honey to extend the honey or change its chemical composition. Luckily sugar syrup additions (e.g. cane, rice, and corn syrups) are relatively easy to detect, as the syrups often include sucrose (honey mainly contains glucose and fructose) or other signifying constituents, that can easily be identified as they dilute the non-sugar portion of the honey. The addition of bioactive ingredients, using the conversion of dihydroxyacetone (DHA) to methylglyoxal (MGO) making the key bioactive constituent of Manuka honey, is more difficult to detect.
The Case of New Zealand Manuka Honey
So how can New Zealand protect its Manuka honey brand? New Zealand Manuka honey is derived from the nectar of only one species of Leptospermum, L. scoparium. It is the only species of this plant genus growing in New Zealand. When the bees collect the nectar and place it in the honeycomb, they bring with the nectar a substance, known as dihydroxyacetone (DHA) that non-enzymatically converts to highly antimicrobial methylglyoxal (MGO). New Zealand first used the presence of DHA and its conversion to MGO as a bioactivity indicator, and this afforded some protection of the source. However, both of these substances can be synthetically produced and added to honey, and this form of Manuka honey adulteration has been exposed. There is also the issue that Australia has the same Leptospermum species as New Zealand, in addition to 80 other species, with more than half of them also producing DHA in their nectar. So measurement of DHA and MGO in honey is not specific to New Zealand Manuka honey as Australian beekeepers can also produce honeys with the same bioactivity mechanism that, like New Zealand Manuka honey, can be adulterated by the addition of DHA and or MGO.
To address this challenge and after much intense analysis, New Zealand researchers identified five specific markers that can be used to authenticate New Zealand Manuka honey. Four of these biomarkers require specified levels of particular chemical substances, with the last, a DNA marker within the pollen. As scientifically impressive as this authentication system is, a recent review highlighted that the required authentication testing is expensive, time-consuming and requires a high level of technical skill and high-end analytical tools. It is also important to note that this system only confirms the identity of one, albeit high-value, mono-floral New Zealand honey. Worldwide, this scenario is the exception rather than the rule, as most honey production from the USA and Europe is from large expanses of agriculture crops or a mixed annual flora meadow, thus nothing as unique and as botanically specific as New Zealand Manuka honey. In Australia, most honey is not harvested from agricultural crops but from wild forest, diverse landscapes with a multitude of, often endemic, flora producing a wide range of mono-or multi-floral honeys, each with a unique phytochemical profile and varying level of bioactivity.
The Case of Australian Honey
Australia has a plethora of unique and often highly bioactive honeys as the continent holds fifteen biodiversity hot spots, each containing rare endemic flora. Importantly the continent supports over 900 Eucalypt species that cover ninety-two million hectares, with an additional thirty million hectares of forest containing other unique nectar-producing trees. It would be a missed opportunity to choose only one or two unique honeys from this plentiful resource. So for Australian honeys, the challenge is to characterise and appropriately market the total forage range. A key task in this undertaking is to ensure consistent high quality, free of accidental or deliberate adulteration.
To protect its brand and the reputation of its products, the Australian honey bee industry has already established its own Quality Assurance System, known as B-QUAL. The system tracks and audits the process of collecting and transporting honey from field to packer and includes food safety requirements. To increase the uptake of B-QUAL among the smaller commercial beekeepers, the CRC for Honey Bee Products joined with B-QUAL to automate the system for greater efficiency and introduce a self-biosecurity audit. This system automation and digitisation of past B-QUAL submissions can also offer the link to timesaving electronic tracking of hives and frames, gathering other critical management data for the beekeeper’s business and assist the peak industry body (AHBIC) to provide government with critical information to protect the industry.
Bee keeping and honey harvesting present a unique set of challenges that sets the industry apart from other agricultural sectors. B-QUAL records and tracks the placement of hives however, honey bees cannot be ‘fenced’ into a paddock or orchard, and will choose their own flight path and flora, from which they will source nectar and pollen to meet their nutritional needs. As can be seen from the case of New Zealand Manuka honey, phytochemical constituents within the nectar will influence the chemical composition of the honey and with it the honey’s organoleptic characteristics and bioactivity profile. It is therefore crucial to understand exactly which plants the bees forage in order to produce honey with stable chemical composition that results in consistent taste and bioactivity. The size of Australia and the complexity of the honey bee forage range might be daunting, but surprisingly the palate of the honey bee appears to be quite selective. Whether this is due to nectar attributes, flower shape, colour or pollen amino acid composition, there are flowers that bees do not venture near. It was found, for instance, that from all the biodiversity in the south-west of Western Australia, honey bees favour only 242 native species.
In 2018, Australian honey unfortunately and unjustifiably, made headlines for all the wrong reasons when claims of adulteration and mislabelling were made. In the wake of what ultimately turned out to be an incorrect claim, a multitude of chemists offered their favourite analytical technique to assist with the authentication through confirmation of sugars and floral source. Regardless of which analytical technique used, all require reliable reference honey samples to build a database against which honey authentication is tested. The problem in Australia is that the industry, until now, did not have a Honey Library against which a honey could be verified.
Establishing such a library requires structure, and the industry elected to use a classification system already established by biologists, the Biogeographical Regions System (https://www.environment.gov.au/land/nrs/science/ibra). A GIS app records where and when the honey was collected so as each sample is submitted into the Honey Library, an analytical chemistry understanding of the signature of the biogeographical region and season can be established. This together with palynology (the study of the pollen within the honey) will verify the honey to the sub-biogeographical region.
The CRC for Honey Bee Products (CRCHBP) has been developing a bee flora database starting with Western Australia and moving across the nation. The database has relied on published literature, flora databases, a Bee Flora Spotter App and observations recorded by researchers. Linking the GPS location of each honey to the CRCHBP bee flora database enables sample source confirmation and acceptance of the honey sample into the Honey Library. In each participating honey chemistry laboratory, the collected honeys are stored using strict and consistent protocols to assist with standardisation and repeatability of analysis.
This Honey Library will take years to complete and most likely, will be continuously expanding as our floral landscape changes. Most of Australia’s flora does not flower every year, for instance, a Jarrah tree is biannual and a Karri tree only has a major flowering once every 20 years. At times even when flowering occurs, the nectar does not flow to levels required for a honey bee colony to produce honey. This is a long-term commitment as is the dedication with any comprehensive collection or library.
This Honey Assurance system will provide a guarantee that the honey is Australian and meets Australian and international standards. To build the Honey Assurance system from the Honey Library, three inter-linked chemistry methodologies for honey characterisation need consideration: alignment with export requirements and the CODEX standard for honey; adulteration; and linking the dominant nectar source in the honey to the harvest biogeographical region. This latter aspect is important for the identification of mono-floral sources, and in particular, for the marketing of bioactive honeys.
The first and simplest approach is to check that all of our honeys meet the CODEX standard for honey. The few countries that have characterised their honeys (mostly in Europe) have identified floral sources that have specific quantifiable chemical components, or pollen counts, that need a special mention as an exception to the honey standard. This could well be true of Australian honeys and the flora sources that cause such anomalies need identification and declared as an exception.
Even when all the recommended tests for CODEX are complete, confidence that the honey is unadulterated and is from Australia is still in doubt. The second layer of chemistry is in hot-debate worldwide. Forensics has taken analytical chemistry to extraordinary levels and the question is if this level of sophistication is required for this food product. The luxury of having a Honey Library is that pilot studies, for performance comparison of different analytical techniques, can use the same samples. The library also offers the opportunity for novel research to identify new rapid and inexpensive methods for honey authentication.
To ensure that an Australian Honey Assurance system is set in place, the first analytical system tested was the High Performance Thin Layer Chromatography. This analytical system requires one machine to measure both the sugar and non-sugar component of the honey, its management is not technically challenging and cost structure opens the opportunity to be standard equipment in a packing operation. Importantly, the technique is well published (and the CRCHBP has been adding to this pool of literature) and there is an Atlas to which signatures of our iconic honeys can be added for world recognition. Whatever chemistry used, to meet legal requirements, the system needs to be ring-tested between laboratories to ensure standardisation and meet legal requirements.
When you see the Australian Batch Number on the honey jar, you will know it has been through this traceability and authentication process and, as a customer, be assured that the honey in the jar is Australian. Packers will be able to go as far as stating provenance (and mono-floral) and vintage, all the requirements of a fine food product.