Sugar for My Honey
Sweets for my sweet, sugar for my honey, are you singing along? I don’t imagine when The Drifters penned this song in the 1960s that some 50 years later their lyrics would be associated with a serious threat to our beloved sweet food stuff. Sugar for my honey or perhaps I should clarify, ‘cheap sugar substitutes for my honey’ is a reality and a hot and sticky topic of investigation for food authenticity researchers.
Honey is one of natures’ oldest sweeteners — produced by bees when they swallow, digest and regurgitate nectar — and has many associated health benefits due to its high levels of antioxidants and anti-bacterial properties. Well known to those who practice Indian ayurvedic medicine where honey has been a staple remedy for many ailments for centuries. Of course it is predominantly sugar, but when you buy a jar from the supermarket you expect the contents to be pure natural honey sugar and not any other type.
With health foods on the rise and more interest in holistic remedies, honey has become an in-demand product. In 2015, honey exports totaled $2.3 billion with China being the largest exporter with over 12% of the market share. The Manuka honey boom saw honey exports in New Zealand almost double1 in a year. As with any success, there can be a down side. Increased reports in crime and vandalism to beehives and threats to beekeepers followed the boom. Because Manuka honey is so special in its unique properties it demands a hefty price tag, and as such, has become the target for mislabelling and adulteration. A recent article in Chromatography Today highlights how chromatography has been used to expose fake Manuka honey flooding the market.
However it isn’t just Manuka honey that is a target for food fraud. Your typical supermarket honey can also be adulterated with cheap sweeteners such as corn syrup and commercial glucose. In recent years, there has also been an influx of imported honey from Asian markets found to contain levels of antibiotics, heavy metals and other nasties which has led to criminal investigations into honey laundering.
There are some simple at home methods to tell if your honey is just honey:
- Honey should solidify; this is a normal crystallization process. If it doesn’t, there is a high chance it has been adulterated.
- Mix some honey with some water and then add a few drops of vinegar. If a foam occurs, the honey might have been adulterated with gypsum.
- Does your honey burn? Light a match and see for yourself (maybe don’t try this at home!) Cheap, low quality honey may have added water which will stop it from burning.
Chances are your laboratory may need more technically valid methods to prove if your honey is sweet! Ion chromatography is one of the techniques that should be added to your arsenal for food authenticity testing.
The Buzz on Carbohydrate Testing
Honey is a complex mixture of sugars with small amounts of proteins (enzymes), amino acids, organic acids, carotenoids, vitamins, minerals, and aromatic substances. The floral source of the honey defines the sugar composition as does climate, processing, and storage conditions. Fructose and glucose, known as reducing sugars, are the major components, which account for 85–95% of all honey sugars. Their concentrations and the ratios can be used to classify monofloral honeys. The remaining carbohydrates are a mixture of at least 11 disaccharides, 11 trisaccharides, and several larger oligosaccharides. These minor honey sugars may be useful to fingerprint the floral origins. Sucrose is also very important in indicating the authenticity of honey. High levels of sucrose may indicate honey adulteration with cheap sweetener,s such as cane or refined beet sugars, and from these regulations have been developed to control maximum amounts of sucrose and minimum amounts of reducing sugars.
Like what you are learning?
Carbohydrate analysis by ion chromatography is well established. High performance anion exchange with pulsed amporometric detection (HPAE-PAD) is a standard tool in food and beverage testing. However, as samples become more complex and the analytes become more challenging, our methods to perform analysis of carbohydrates have to become more sophisticated. In a recent application note the new Thermo Scientific™ Dionex™ CarboPac™ PA210-4µm column has been used to profile di- and trisaccharides in honey as well as assay the fructose and glucose content. Harnessing advances in high pressure ion chromatography utilising small particle columns enables improvements in column efficiency and resolution plus the ability to run samples faster. The new generation of Carbopac columns work with lower strength eluents, meaning eluent generation can now be used and the need to run conventional mixed gradients is now not always necessary.
Using this technology, a new method was developed profiling 15 honey sugars in 25 minutes, with a number of honey samples adulterated with sugar syrups to show the effect this has on fructose and glucose ratio and sucrose levels. It is detailed in the application note.
Swat up on food fraud with this recent webinar in conjunction with New Food magazine: When honey is not all honey and other tales of food adulteration: Ion chromatography as a tool for detecting food fraud
For more on food integrity see our dedicated web page
For isotope analysis about honey, read more here.