*3.2.1.3 eDNA would reveal the authenticity of honey*

*Modern Beekeeping - Bases for Sustainable Production*

of each honey-source plant accurately [9, 48].

*3.2.1.2 Is it honey from acacia trees?*

honey from hairy vetches.

honey specialty for sale. Thorough analysis on radioactivity is in place for food safety and has been verified with the eDNA analysis technique that the product is

Identification of honey-source plants with eDNA analysis technique has been tried since around 2010 (**Figure 3**). It has some advantage over the conventional pollen analysis, but it is not fully verified that it can demonstrate a level of contribution

Although DNA is an effective indicator of honey-source plants, most honey products do not show the results of their DNA analysis. In Gifu Prefecture where beekeeping is active, it is indicated on the label on some of the honey products that they are from

The eDNA analyses were conducted on 14 honey products purchased at high-end supermarkets in Tokyo. None of the products sold as single-flower honey/monofloral was actually from a single source. The DNA of false acacia was detected in all of the seven well-known acacia brands, but it was dominant in only four of them and the second-dominant following other plants in the other three products. In some of those sold as honey from a single source such as astragalus, ilex, amur cork, buckwheat, or manuka, these nominal source plants were not the dominant sources, or their DNA was not detected at all. None of the products analyzed was actually from

cherries and ilexes by their DNA analysis, but this is one of the few examples.

a single source. Since honeybees visit various flowers, this is not surprising.

Acacia single-flower honey is much sought after in Japan, and it is traded at a high price. Among the seven acacia monofloral/single-flower honey products, however, acacia was found to be a dominant source for honey only in four of them, and the other three products contained honey only from false acacia as its seconddominant source. A product sold as monofloral honey may actually have been from several source plants/multifloral honey. Astragalus honey made in Tokyo is from

*An example of analysis results of honey we produce. More than 20 kinds of plants were confirmed. With the exception of* Prunus maximowiczii*,* Wisteria floribunda, *and* Trifolium repens*, most species are not famous* 

*as honey source plants. Based on data from IDEA Consultants, Inc.*

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**Figure 3.**

Verifying the quality of high value-added honey is important for the development of a healthy beekeeping industry. Thus, DNA analysis can be a powerful tool to identify origins. If the list on the label contains a plant species that does not grow in the local area or does not contain the DNA that should be detectable as a species on the product label, it may be misrepresenting the honey and its origin.

We analyzed 14 honeys purchased at a luxury supermarket (**Table 1**). More than half of the products contained plant DNA on the label, but some products were not detected at all. Manuka DNA was not detected in the Manuka honey analyzed this time. Manuka honey may have been shipped after aging for several years after harvest, so it is possible that DNA degraded during this aging period. DNA is generally unstable and fragile. Since it breaks down over time, there is a possibility that the labeled honey source cannot be detected by DNA analysis, even if it is correct. However, this sample remains suspicious because it has confirmed several plant DNAs normally growing in New Zealand. Following the accusation that their Manuka honey was fake, New Zealand authority has mandated DNA analysis for their Manuka honey since 2018 [49].
