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Last Updated
21-Aug-2009
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orld
Wide the International Standards for Honey are laid out in the
Codex Alimentarius
(administered by the "Joint FAO/WHO
Food Standards Programme") to which New Zealand is an active
signatory. The Codex standard for honey can be seen in PDF form
here.
The relevant section for monofloral honeys in the Codex Alimentarius
is:
Section
6 Labelling
Section 6.1 The Name of the Food
Subsection 6.1.6
"Honey may be designated according to floral or plant source
if it comes wholly or mainly from that particular source and
has the organoleptic, physicochemical and microscopic
properties (our emphasis) corresponding with that
origin."
It is
clear that some measurements have to be applied to a specific
honey to determine if it is in fact what is claimed to be on
the label. To this end we routinely measure the following:
All monofloral
honey types we deal with have a limited range of values for
each of these measurements. By taking each measurement and comparing
it with the average value and standard deviation of the target
honey type, we are able to determine, with excellent repeatability,
if a honey type is true to label.
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Colour of Honey
- Pfund
Grader

oney
colour is measured on a "Pfund Grader". The scale for this is
called the "Pfund" Scale and is measured in millimetres. The scale
is actually a metric ruler measuring the point along a calibrated
amber glass wedge where the sample (placed in a glass wedge shaped
trough) matches the amber wedge. The scale starts at 0mm (colourless)
and finishes at 140mm (black). Some common terms describing the
colour of honey actually have specific ranges on the Pfund Scale.
These also vary slightly from country to country with the USA,
Canada and Australia all having slight variations. The US scale
is :
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0-8mm
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Water
White
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Up
to 17 mm
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Extra
White
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Up
to 34 mm
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White
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Up
to 50 mm
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Extra
Light Amber
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Up
to 85 mm
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Light
Amber
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Up
to 114 mm
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Amber
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Over
114 mm
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Dark
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In many cases we have over 1,000 samples on file
for a particular honey type and are able to compare the average
colour plus Standard Deviation of the colour with that of a sample
under analysis. |
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Pollen Analysis
here are
several papers in the scientific domain that refer to microscopic
analysis and pollen analysis in particular that give broad
indications of required levels of pollen for a single floral
source statement to be made. In New Zealand, a paper titled
"Pollen
Analysis of New Zealand Honey" was published in the New
Zealand Journal of Agricultural Research in 1985. This paper
gives required levels of pollen for specific New Zealand honeys.
It is therefore the source document that would be used in applying
section 6.1.4 from the Codex standards.
Pollen Analysis is based on identification of pollen in a sample
of honey but may also extend to indentfication of other particles
in the honey e.g. in the case of honeydew.
Pollen finds its way into honey by two routes. Firstly, and
most importantly for pollen analysis, pollen naturally falls
into the nectar at the flower. This is collected by the bees
and taken back to
the hive to be ripened into honey. Different plants produce
a wide range of pollen sizes and types. This along with the
structure of many flowers affects how much pollen on average
falls into the nectar and (thence into the honey) for a given
plant species.
A good example of how flower structure can affect the incidence
of pollen in nectar is New Zealand Fuchia (Fuchia excorticata).
Here the anthers and pollen hang down
and are physically separated from the nectaries. Fuchia is primarily
a bird pollinated plant and the flower structure is adapted
to putting pollen onto a bird collecting nectar. Pollen falling
off the anthers falls away from the nectaries and bees collecting
nectar do not come into contact with Fuchia pollen. It is an
uncommon pollen in New Zealand honey, in spite of Fuchia being
considered a good Spring nectar source.
In
the honey World, three classifications have been
proposed. Honeys are deemed to be Under, Normally or
Over represented. Under represented is deemed to be nectar
sources that produce honeys with less than 20,000 pollen grains
per 10 grams of honey. Normally represented are those with 20,000
- 100,000 pollen grains per 10 grams of honey and over represented
honeys have more than 100,000 pollen grains per 10 grams. When
looking at the percentages of pollen in a honey sample, the
classification the various nectar sources fall into has to be
taken into account. For a honey to be identified as a monofloral
honey type, e.g. "clover", "manuka" etc. the following levels
should typically be met:
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- Under
represented pollens, a level of greater than 20%
of the target pollen must be identified,
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Normally represented pollens, a level of greater
than 45 % of the target pollen,
- Over
represented pollens, a level of greater than 70%
of the target pollen is require
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The
other way that pollen can arrive in honey is from contaminating
sources. This typically happens during the extraction
process when pollen in the frames (collected and stored
by the bees for a protein source) is removed with the
honey.
This pollen may not be the same source as the nectar source
and is collected independently by bees foraging specifically
for pollen as opposed to nectar. In a routine pollen analysis
the total pollen content of the honey should be measured
to see if there is a "masking" effect from contaminating
pollen at time of extraction. The total pollen figure
should not be a magnitude higher than normal for the target
species.
In fact the simplification of "Under, Normally and Over"
represented honey types does not cover all possible situations.
Many plants do not end up with significant pollen from
the source plant in the nectar. Nodding Thistle is one
of these. We believe the structure of the flower, (long
thin florets tightly packed together) and the large size
of the pollen grains (around 60 microns) prevent much
NT pollen from getting into the nectar. We have found
that most NT honey only has around 500 - 1,000 pollen
grains per 10 grams. This is an extremely low figure and
means that as a percentage of other pollen types that
get into the nectar from other sources (or from other
nectar sources collected with the [predominantly]
NT nectar) NT is very low. This is often less than 10%.
Pollen analysis is a valuable tool for honey identification,
however it should be pointed out that this is a complex
subject and is always used in conjunction with other information
before a final determination is made.
Additional References on Pollen
Analysis.
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Conductivity
Measuring
conductivity is an indirect way of measuring the mineral content
of a honey. As sugars in solution (the main component of honey)
are poor conductors, any minerals present in the honey aid the
ability of honey to conduct electricity. For honey, this is
expressed as ohms/cm
X 10-4 taken
in a solution of honey and distilled water (at 20°C) where
the dry mater of the honey makes up 20% of the weight of the
solution.
Typically flower honeys are less than 1.5 while honeydew honeys
are greater than 8.5. There are of course some exceptions to
this and this feature is an aid in the identification of these
honey types. Also blends of honeydew honeys and flower honeys
will give an intermediate value. Manuka
is one flower honey that has a much higher than usual conductivity
for a flower honey.
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Sugar
Analysis
As
the largest component of honey, sugars are an important part
of honey identification. The two main sugars are fructose and
glucose and the ratio of these two sugars can be a useful determinant
for identification. We use HPLC (High Performance Liquid Chromatography)
as our analysis method, and while relatively new to our laboratory,
is giving us new found insights into the honeys we work with.
While
fructose and glucose are the major sugars, there is a vast array
of more complex sugars found in honey and each honey has its
own spectrum of sugars that are typical to that honey. Of interest
in honeydew is the presence of oligosaccharides.
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