Issues with adulteration of Australian honey

1. Honey testing: To bee or not to bee!

2. The Problem:
Big honey companies
are blending imported
honey with local
produce but the
imported honey is
adulterated – it
contains sugars added
from other sources.
Testing to prove this
has been either non-
existent or
inadequate.

3. FAIL!
12 out of 28 common supermarket brands
tested failed.

4. Why adulterate honey? – to cut costs. Adding water will make
each litre of honey go further, adding cheaper sugars saves
money.

5. What is in honey?
A range of sugars, organic acids
and flavonoids.
% Water is around 17%. Added
water can be detected this way.
Fructose:glucose is 38:31.
Adulterated honey will have a
different ratio.

6. Sugars: Carbohydrates
Your textbook will tell you that
glucose and fructose are
examples of monosaccharides.
Your textbook does not mention
that there are hundreds of other
important monosaccharides.
They are classified by the
number of carbon atoms in the
backbone.
Glucose is a hexose or C6 sugar.
The molecule on the right is a
tetrose, a C4 sugar.

7. Detecting adulterated honey is about detecting the
presence of C4 and C3 monosaccharides.
Added sugar cane syrup increases the level of C4s
Added rice syrup increases the level of C3s

8. NMR: nuclear magnetic resonance
Full NMR – each coloured line is a different sample of pure honey. Note the consistency in the
shifts at which peaks appear.

9. The NMRs on the previous slide are so precise that they can
be used to identify the country of origin of the honey.
The composition varies with the climate, species of bee and
species of plants the bees feed upon.
The NMR stores the spectrum to use as a reference against
future tests.
The presence of C3 sugars adds peaks in unexpected shifts.
The peak areas provide information about the likely
concentrations of the sugars present –adulterated sugars
will have different sugar ratios.

10. Specific shift regions are studied for a honey ‘fingerprint’. The sample
below is for shifts between 3.2 and 5.3 corresponding to common
monosaccharides.

11. High shift regions

12. Bottom line is this
• various honeys have distinctive NMR patterns.
• the presence of added sugars will produce peaks that
should not be there or will enhance peaks that are
present.
• heat treatment of honey will change the characteristic
NMR spectra as the chemical composition of sugars
can be changed by heat.

13. Adulteration is not limited to honey. Check out the two maple syrups below.

14. Conclusion
Buy honey from your local farmers market or buy Beechworth
honey – completely Australian produce.