EXPERT REACTION: Honey fraud

There are three main ways that honey can been adulterated:

1. Harvesting the honey before the honeycomb is sealed. This would mean that the ripening process would be incomplete. The conversion of sucrose to fructose, glucose and maltose would be unfinished and the moisture content would be higher than the required 17.1 per cent. This can be tested by measuring the sugar proportions and moisture content. Drying machines have been developed to overcome moisture content detection.

2. Honey bees are fed sugar syrup. A husbandry practice in beekeeping is to feed honey bees sugar syrup between flowering events so that they do not die when too much honey has been harvested from the hive to tide the colony over. Sugar syrup feeding can be extended to more than just ‘intervals’ to the point that the main carbohydrate source is syrup. This can be tested by measuring the honey profile which will show a lack of other honey components such as polyphenols, flavonoids and minerals.

3. Direct addition of a portion of sugar syrup to dilute and extend the honey. The method of detection of this adulteration depends on whether the sugar syrup added is derived from a C3 or C4 plant. Plants differ in the way they capture carbon dioxide during photosynthesis. All species have the more primitive C3 pathway, but the additional C4 pathway evolved in species in the wet and dry tropics. A cane sugar or high fructose corn syrup will increase the C4 sugars. To test for the presence of this sugar syrup, a C4 sugar test is used which analyses the ratio of the two most common isotopes of carbon (12C and 13C). If the honey has not been adulterated, the ratio of 13C/12C from that honey will be very close. However, if sugar has been added, the ratio of 13C/12C will be different. Internationally it is accepted that the difference in the ratio of 13C/12C in unadulterated honey will be less than or equal to seven per cent (Grainger, 2015).

When sugar syrup is used from a C3 plant, or a mixture of C3 and C4 plants, the C4 sugar test cannot be used. The new sugar syrups using the C4 test pass undetected when added to honey. This has left the industry in a difficult situation as, worldwide there is no accepted system by which adulterated honey can be detected.

How will the NMR [nuclear magnetic resonance] technique help to protect Australian honeys?

The concept behind the new chemistry is to create detailed chemical profiles of honey. Honey is made up of a mixture of carbohydrates, polyphenolics, flavonoids and minerals that makes up a unique profile for each honey from a different nectar source. A database of these profiles would need to be developed so that they could be used as a reference. A suspected adulterated honey profile would need to be compared to this database. If components have been added to the honey, such as more sugars, these additional sugars would not be in proportion with the other identifying substances in the honey profile. It would then be obvious that the product has been adulterated.

The sensitivity of this test would be related to the breadth of the honey sample population included in the database.

NMR is one analytical chemistry technique that gives a very detailed chemical profile of honey. There are alternate analytical systems that can provide equally detailed chemical information. It is Important that there is industry agreement on the chemical profiling system, that is: the methodology used to prepare the sample as well as the equipment and operating conditions the machine is set to run the sample. This would require standardisation across analytical laboratories within Australia and worldwide.

Honey is under threat.

There is no significant evidence of honey being mixed with cheap sugar syrups (derived from a range of crops including corn and sugar cane) that allows the mixed product to be sold much cheaper and thereby undercutting pure honey producers.

But there is a test available, known as the C4 test (because it can detect the difference in products that come from normal plants, known as C3 plants, from those with an alternate photosynthesis metabolism, known as C4 plants and is common in tropical grasses such as corn and cane) which can identify if honey has been mixed with sugars from rice, cane and corn.

This test has been available for some time, but the honey fraudsters are becoming more cunning and mixing honey with other syrups that can't be detected by the C4 test, such as syrups from wheat and beets.

The latest honey fraud issues have involved a new test, based on recognition of different types of sugars using Nuclear Magnetic Resonance Spectroscopy and done by a company in Germany, which can purportedly detect these other syrup adulterants. Several Australian suppliers of honey (including Capilano Allowrie-branded Mixed Blossom Honey, Aldi’s home brand and IGAs black and gold brand), have been implicated in the mixing of honey containing these adulterants using this test.

The Australian honey bee industry now wants to move to this type of testing.

This will be a useful test for the industry to detect honey fraud.

The honey bee industry says that as we cannot be certain about the outcome of the test because of lack of information about the types of sugars in most honey types, but the company doing the tests maintains that the database is quite extensive. It is also likely that other tests will be developed to help combat this type of fraud, for example pollen analysis of honey.

Nevertheless, for those who want to buy unadulterated honey, their best bet may be to buy honey that is 100 per cent Australian – this way they will also support Australian beekeepers.

This is a huge issue. Counterfeit honey undercuts the price of real honey. Blending honey with sugar syrup, corn syrup and rice syrup significantly reduces costs and it makes it difficult for local beekeepers to compete. If the honeybee industry is undermined by making it unprofitable, then we will lose beekeepers. Many crops rely on honeybees for pollination, so this will have long-term repercussions for our food security.
 
Honey has antibacterial properties. It also has lower GI [glycaemic index] than other sweeteners and contains antioxidants. Fake honey is not honey. You should always have confidence that the food you pay for is the food you get.
 
Whenever a new test is brought out, the honey adulteration industry begins work to be able to pass the tests. For example, they switch from using corn syrup to using rice syrup because this passes the C4 test. This is a lucrative industry. It is best to use several methods and not continue using the same single test that you always have.

Food fraud is very dangerous for Australian food industries. We need our beekeepers and they need a fair market in which to sell their honey. Australian honey is known to be of high quality, but it is difficult to compete when the market is deliberately undercut. There is a concern worldwide about the loss of pollinators, which are under stress, we can’t afford to lose the beekeeping industry.
 
Better food labelling would not stop the honey fraudsters;  they are trying to pass off an adulterated product as genuine and they go to a lot of trouble to try and beat the tests that can identify it. Approximately 5 per cent of honey imported to Australia is tested, this needs to be drastically increased and mislabelled products sent back, making it unprofitable.
 
We need to support Australian beekeepers by checking the label and only buying 100 per cent Australian honey.

If there is a demand from the beekeeping industry and consumers for more stringent testing of honey, and the NMR method is to be introduced as the new ‘norm’, then we have to ensure that the honey derived from our unique Australian flora (nectar) is well represented in the reference database that is used in this technique.

Very simply, NMR can give us a ‘fingerprint’ of what is in a sample – and this fingerprint is matched back to a reference database to identify the components within that sample. If different testing labs use different databases, there can be instances where the same sample can have different results depending on the lab. With an extensive and universally used database, the NMR method can be extremely sensitive and powerful in detecting food adulteration.

If this type of testing is done mainly in Europe and the database is built predominantly on European (or other non-Australian) floral, nectar and honey samples then there may be some limitations that need to be addressed before we use this for robust testing of Australian honey samples.

Australian law is absolutely clear that food sold as 'honey' must in fact be honey, as defined under the Australia New Zealand Food Standards Code. Selling a product labelled as honey that isn’t in fact honey is an offence in the various states and territories. Producers and retailers can be held responsible and fined.

Labels must also say what is in the food – so failing to declare other ingredients that have been blended with the honey can also be an offence. If allergens or toxic substances have been added and not declared, this is an even more serious offence.

Nevertheless, food fraud experts point out that honey is one of the most commonly mislabelled foods around the world. Food regulators in Australia don’t regularly test foods produced and consumed within Australia to make sure that they comply with prescribed definitions.

The Australian government reportedly does test samples of honey coming into Australia for safety and for correct description. But food fraudsters constantly come up with new ways to cheat tests designed to root out food fraud, and regulators must keep ahead of them.

So even though we have a strict law about what honey should mean, it isn’t always well monitored and enforced, and some falsely labelled honey may well end up on our supermarket shelves.