Project Summary - AgriFutures Australia...2018/11/18 · “The Honey Launderers”, Bloomberg Business Week, 19/09/2013). Australia’s honey industry currently does not have an

Project Summary

Verifying the origin of Australian honeys by analysis of their pollen content

Research objectives

This project aimed to gather and analyse data on the pollen content of a wide range of geographically representative, unprocessed Australian honey samples, in order to examine whether it would be feasible to use pollen analysis to verify the origin, at continental scale, of Australian honeys. This knowledge should help efforts to expand markets for Australian honey, both domestically and for export. In addition, the project also aimed to provide basic knowledge of the foraging preferences of honey bees in Australia, which has never been examined systematically through analysis of honey.

Australia’s honey industry currently does not have an independent basis for verifying the authenticity of honey, both in terms of its geographic origin, and its botanical origin.

The issue

Australia’s honey industry is threatened by increasing trade in adulterated or counterfeit honey, both domestically and internationally (ACCC media releases NR 160/14, MR290/14; “The Honey Launderers”, Bloomberg Business Week, 19/09/2013). Australia’s honey industry currently does not have an independent basis for verifying the authenticity of honey, both in terms of its geographic origin, and its botanical origin. Melissopalynology (pollen analysis of honey) is widely used to verify the botanical and geographic source of honeys (Aronne and De Micco 2010; Dimou et al. 2014; Terrab et al. 2003; von der Ohe et al. 2004), but has never been systematically tested in Australia. However, the use of pollen analysis to verify the origin of honeys requires knowledge of relationships between honey pollen content and source vegetation, which is currently unknown for Australia.

European honey verification laboratories, using palynological criteria developed on European honeys, have found some Australian honey samples unrecognisable even as “Eucalyptus honey” (RIRDC 2014, Value Adding to Honey). Hence mechanisms for the international recognition of the authenticity of Australian honey currently are poorly developed, or even misleading, which could negatively impact on the sale of Australian honey in overseas markets. The Australian honey industry would benefit from an internationally recognised, scientifically rigorous certification process that could verify the botanical and geographic origins of a honey sample. Equally, Australian consumers would benefit from certification by gaining confidence that the product they were supporting was indeed made in Australia, and not adulterated with products from overseas.

Learn more agrifutures.com.au/honey-bee-pollination

Dr Kale SnidermanSchool of Earth Sciences, University of Melbourne PRJ-009770

Methods

Raw, unblended honey samples were sourced directly from beekeepers, via two major Australian honey packers, Beechworth Honey and Capilano Honey. 173 samples (Figure 1), from southern Queensland (mostly in the southeastern corner, but with a small number of samples from the semi-arid southwest of the State), eastern New South Wales, Victoria, southeastern South Australia, and southwestern Western Australia (SW WA) were analysed for their pollen content, using standard palynological techniques (Louveaux et al. 1978; Moore et al. 1991). Tasmania was unfortunately excluded, with the exception of one sample from Flinders Island. For 124 of the samples, extraction dates were available; the majority (75%) of these 124 samples were produced in Spring or early Summer (September through January).

Results

Australian honeys are dominated by pollen of Eucalyptus (Myrtaceae), along with other Myrtaceae such as Corymbia/Angophora and Leptospermum and its relatives; Brassicaceae (presumably mostly cultivated Canola), Echium (largely E. plantagineum, an extremely heavy pollen producer (Martin Arroyo et al, 2017), known by Australian apiarists as ‘Salvation Jane’), Macadamia and Acacia are also numerically important pollen types, along with a large number of minor pollen types (Figure 2). Some Australian

honeys include pollen of plant genera or families that grow only, or primarily in Australia. The presence of these pollen types, either alone or in combination with other evidence, could reliably indicate the Australian origin of these samples. Examples include Banksia and Hakea (Proteaceae), Bursaria (Pittosporaceae), Eremophila (Myoporeae:Scrophulariaceae), Leucopogon and Monotoca (Ericaceae). However, each of these pollen types was present in only a subset of the honey samples, and therefore none can be relied upon to be present in any given Australian honey.

A more pervasive feature of the honeys was simply the number of visually distinctive Myrtaceae pollen morphotypes present in each sample. That is, the pollen assemblages of most of the honey samples were found to include a relatively large number of pollen types attributed to the plant family Myrtaceae (Figure 3), a very diverse, ecologically dominant, and widespread plant family in most southern Australian native vegetation. Characteristic genera include Eucalyptus, Corymbia, Melaleuca, Leptospermum, and many others. Comparisons with previously published studies describing the pollen content of honeys produced in other countries, suggest that high Myrtaceae pollen morphotype diversity may distinguish Australian honeys from honeys produced in any other country.

Figure 1 Location of the 173 honey samples within Australia.

Learn more agrifutures.com.au/honey-bee-pollinationAgriFutures Australia is the trading name for Rural Industries Research & Development Corporation.AgriFutures is a trade mark owned by Rural Industries Research & Development Corporation.

Figure 1

5000km

Queensland

New South Wales

Victoria

South Australia

Western Australia

NorthernTerritory

Tasmania

Figure 2 Pie chart illustrating the proportional abundance of the most important pollen types observed in the 173 Australian honey samples.

Two examples illustrate this. First, Eucalyptus is widely planted in the Mediterranean region, where its honey is prized. However, Mediterranean Eucalyptus honey is produced mainly from only one or other of two species of Eucalyptus (Cerasoli et al. 2016; Feás et al. 2010), and only one native Myrtaceae species is present in the region (Myrtus communis). Unsurprisingly, then, studies of the pollen content of Mediterranean honeys rarely report more than two Myrtaceae pollen types, not only within individual samples, but even in studies of up to 100 or more honey samples (Seijo and Jato 2001). Second, South America has a very diverse native Myrtaceae forest flora, consisting of thousands of species within ca. 29 genera (Wilson 2011), in addition to several Eucalyptus species that have been planted or naturalised in various regions.

However, pollen analyses of South American honeys routinely report 1-2 Myrtaceae pollen types (Forcone 2008), one of which typically is Eucalyptus, apparently because the pollen morphology of the South American Myrtaceae flora exhibits very little morphological variation. In contrast, the Australian Myrtaceae pollen flora shows a striking range of morphological variability (Thornhill and Crisp 2012), allowing the identification of numerous distinct types. In this study Myrtaceae pollen grains could be identified to genus- or species- level in only a few cases, but it was nevertheless relatively straightforward, within individual samples, to assign observed Myrtaceae pollen grains into distinct morphological categories. The resulting morphotypes diversity (0-11 morphotypes per sample, with an average of 4.6) appears to distinguish Australian honeys, even from Mediterranean and South American honeys, which would be expected to most closely resemble Australian honeys.

Most Australian honeys are produced largely from bees’ foraging within native vegetation (RIRDC 2014). It might be expected that Australian honeys produced primarily in agricultural landscapes would be more difficult, or impossible, to authenticate using pollen analyses. This is true for some samples, particularly those strongly dominated by Brassica pollen. However, some predominantly agricultural samples, especially those from southwest Western Australia, nevertheless include a substantial number of Myrtaceae (and Proteaceae) morphotypes, presumably reflecting their production in landscape mosaics containing both agricultural land and native vegetation.

The identification of pollen-based characters that could be used to verify the origin of Australian honey samples may be useful to beekeepers, honey producers, and honey exporters, because it could allow the development of a pollen-based certification procedure that would verify the authenticity of Australian honeys.

More information is provided in the peer-reviewed publication, Sniderman et al. 2018, Pollen analysis of Australian honeys: https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0197545


Figure 3 Microphotographs illustrating the range of Myrtaceae pollen types encountered in the honey samples. Individual honey samples typically contained 4.6 Myrtaceae pollen types, on average.

Implications

The results of this project could be used to inform the development of a quality-control process designed to authenticate the origin of Australian honeys. If such a quality-control scheme were Government accredited and internationally visible, it may have the potential to increase the market value of Australian honey, both domestically and internationally, based on the premium prices often achieved with accredited unifloral honeys. A certification process would also provide a mechanism to assess fraudulent labelling of honey as ‘Australian’. The potential economic justification for such a quality-control scheme is outlined below.

Assume the wholesale price of honey is ~$4000/tonne, and that pollen analysis of a single honey sample would cost $200, a typical and sustainable fee for a specialist laboratory-based analysis, if conducted as a part of a routine certification operation (all values in Australian dollars). Because the increased profitability that might be achieved from applying a pollen-based certification is currently speculative, we make calculations based on a range of increases, from 1% to 10%, in either the realised wholesale price of honey (from $4040/kg to $4400/kg), or the quantity of honey sold. In addition, because of uncertainty about the beekeeping industry’s and buyers’ perceptions of the acceptable size of an individual analytical honey batch, we make calculations in which the size of the analysed sample ranges from 0.5 to 3 tonnes. Return on investment (ROI) is calculated as:

ROI = (gain from investment – cost of pollen analysis) / cost of pollen analysis

Figure 4 illustrates the ROI resulting from a fixed pollen analytical cost of $200 and an initial honey price of $4000/tonne, with the increase in price or quantity sold ranging from 1 to 10%, and the mass of the analysed sample ranging from 0.5 to 3 tonnes. Intersections of each line with the zero value of the ROI axis represent the cost-neutral point for each combination of sample mass and increased price or quantity sold. Figure 4 indicates that if the increased price or quantity sold is not more than 1%, returns on investment will be negative unless the size of an analytical batch is considerably greater than 3 tonnes, which may be perceived by customers as too large. If the perceived necessary size of each analytical batch is very small (0.5 tonnes), ROI is consistently negative, and only becomes cost neutral if the increased price or quantity sold is ≥ 10%. However, for increases in price or quantity sold of 3% or more, returns on investment are positive for analytical batches as small as ~2 tonnes; for increases in

price or quantity sold of 5%, the analysis of a sample as small as one tonne is cost neutral, and the ROI is highly positive for sample sizes of two tonnes. These calculations indicate that, if the realistic sample mass is in the 1-2 tonne range, a new pollen analytical authentication procedure may be worthwhile to honey producers and/or exporters if it increased the price of honey or the quantity sold by at least ~4%.

To provide one worked example, if the size of an analytical batch was 2 tonnes and the pollen certification increased profitability by 4%, then the ROI would be:

Gain from investment of a single analytical batch: ($4000× 2) × 0.04 = $320.

ROI = ($320 - $200) / $200 = 60%

These calculations are speculative, but the suggested cost of analysis is broadly realistic, and the calculations provide an indication of the balance between the costs and potential financial benefits of melissopalynological certification. If it assumed that the size of the smallest honey batch requiring verification is 1 to 2 tonnes, then it is apparent that under any circumstance in which pollen analyses contributes to an increase in the wholesale price of honey by ~4% or more, the expense of verification is recouped by the seller.


Figure 4 Indicative returns on investment of a new pollen analytical authentication process, for a range of sizes of an individual honey sample (from 0.5 to 3 tonnes) and for a range of resulting increases in honey price or quantity of honey sold (from 1% to 10%).

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Based on conservative assumptions about the positive impact of a pollen-based certification on honey prices or on the quantities of honey sold, a new pollen-based certification scheme could be financially beneficial, especially in markets sensitive to questions of potential adulteration of honey. Establishment of an effective, visible and authoritative pollen-based certification scheme for Australian honey would need to be supported by an appropriate Government-endorsed statutory body, in order to ensure widespread, domestic and international recognition of the certification. Honey producers, packers, exporters, and Australian honeybee industry stakeholders should consider whether it would be useful and profitable to develop and support such a new, pollen-based certification scheme.

References Aronne G. & De Micco V. (2010) Traditional melissopalynology integrated by multivariate analysis and sampling methods to improve botanical and geographical characterisation of honeys. Plant Biosystems 144, 833-40.

Cerasoli S., Caldeira M. C., Pereira J. S., Caudullo G. & de Rigo D. (2016) Eucalyptus globulus and other eucalypts in Europe: distribution, habitat, usage and threats. In: European Atlas of Forest Tree Species (eds J. San-Miguel-Ayanz, D. de Rigo, G. Caudullo, T. Houston Durrant and A. Mauri) p. e01b5bb+. Publishing Office of the EU, Luxembourg.

Rural Industries Research and Development Corporation (RIRDC) (2014) Honey bee and Pollination Program Five Year Research, Development & Extension Plan 2014/15 – 2018/19 Publication No. 14/057.

Dimou M., Tananaki C., Liolios V. & Thrasyvoulou A. (2014) Pollen foraging by honey bees (Apis mellifera L.) in Greece: botanical and geographical origin. Journal of Apicultural Science 58, 11-23.

Feás X., Pires J., Estevinho M. L., Iglesias A. & Pinto de Araujo J. P. (2010) Palynological and physicochemical data characterisation of honeys produced in the Entre-Douro e Minho region of Portugal. International Journal of Food Science and Technology 45, 1255-62.

Forcone A. (2008) Pollen analysis of honey from Chubut (Argentinean Patagonia). Grana 47, 147-58.

Louveaux J., Maurizio, A. & Vorwohl G. (1978) Methods of Melissopalynology. Bee World 59, 139-57.

Martin Arroyo T., González-Porto A.V., & Bartolomé Esteban C. (2017) Viper’s bugloss (Echium spp.) honey typing and establishing the pollen threshold for monofloral honey. Plos One. 12, e0185405.

Moore P. D., Webb J. A. & Collinson M. E. (1991) Pollen analysis. Blackwell Scientific Publications, Oxford.

Seijo M. C. & Jato M. V. (2001) Distribution of Castanea pollen in Galician honeys (NW Spain). Aerobiologia 17, 255-9.

Terrab A., Díez M. J. & Heredia F. J. (2003) Palynological, physico-chemical and colour characterization of Moroccan honeys: I. River red gum (Eucalyptus camaldulensis Dehnh) honey. International Journal of Food Science and Technology 38, 379-86.

Thornhill A. H. & Crisp M. D. (2012) Phylogenetic assessment of pollen characters in Myrtaceae. Australian Systematic Botany 25, 171-87.

von der Ohe W., Persano Oddo L., Piana M. L., Morlot M. & Martin P. (2004) Harmonized methods of melissopalynology. Apidologie 35, S18-S25.

Wilson P. G. (2011) Myrtaceae. In: Flowering Plants. Eudicots (ed K. Kubitzki) pp. 212-71. Springer-Verlag, Heidelberg.


This project indicates that the pollen content of most Australian honeys is distinctive, at global scale, and that pollen analyses would allow Australian honeys to be identified and certified as produced in Australia.

Contact

Dr Kale Sniderman School of Earth Sciences University of Melbourne 03 9035 9873 [email protected]

AgriFutures Australia Project No.: PRJ-009770 AgriFutures Australia Publication No.: 18/042

Documents

Project Summary - AgriFutures Australia...2018/11/18 · “The Honey Launderers”, Bloomberg Business Week, 19/09/2013). Australia’s honey industry currently does not have an