9.9 Double Points from 9th September — 11th September

Mānuka Honey is greatly prized for its anti-bacterial, anti-inflammatory, anti-viral and antioxidant health benefits. That’s the reason why many are willing to extend their earnings to purchase this honey that is after all, not cheap.

But Mānuka Honey is not always Mānuka Honey!

With Mānuka Honey being a high value export and the rise of international demand - this also has coupled with the rise in batches of Mānuka Honey adulteration. FMD Mānuka Honey has gone through a suite of tests (as displayed in the Certification of Analysis) allowing consumers to check on the authenticity, quality and composition of each FMD Mānuka Honey jars. Furthermore, microbiological tests were carried out to ensure safe consumption of the product. This is so that our consumers can rest assured that they are getting real ‘jars of gold’ instead of ‘jars of no(s)’.

The below summarizes the main paths of Mānuka Honey adulteration as well as a number of tests that can help to ensure the quality and authenticity of FMD Mānuka Honey.

 

Honey Adulteration

Honey Adulteration Types Tests to Identify Potential Adulteration
  • Direct Adulteration
    Mānuka Honey diluted or added with water / low-cost sugars / commercial sugar syrups as a post-production procedure.
    • Apparent Reducing Sugars
    • Apparent Sucrose
    • Ash
    • C4 Sugar
    • Indirection Adulteration

      Feeding bees with honey / chemicals / industrial sugar / sugar syrups instead of Mānuka nectar to increase honey yield in hives.

    • Apparent Reducing Sugars
    • Apparent Sucrose
    • Ash
    • C4 Sugar
    • Blending

      Mixing pure Mānuka Honey with cheap or low-quality honey.

    • Apparent Reducing Sugars
    • Apparent Sucrose
    • Ash
    • DHA
    • Leptosperin
    • MGO
    • Mislabeling
      Poor quality Mānuka Honey or other types of honey directly labelled falsely as higher value Mānuka Honey.
    • Apparent Reducing Sugars
    • Apparent Sucrose
    • Ash
    • DHA
    • Leptosperin
    • MGO
    • Heating
      Higher temperature accelerate conversion of DHA to MGO in
      Mānuka Honey.

      Mānuka Honey is heated to increase content of MGO to make it more valuable commercially. However, heating destroys enzymes and antioxidants of honey.
    • Apparent Sucrose
    • Diastase
    • HMF

     

     *Example of Certificate of Analysis from FMD's Mānuka Honey

     

    Chemistry Tests

    No

    Test

    Reference Value

    Description

    1

    Apparent Reducing Sugar

    Not less than 65%

    Fructose and glucose are reducing sugars and are the major components (to exceed 65%) of sugars in honey. This is to detect if the Mānuka Honey has the right composition, as lower values may indicate Mānuka Honey has been blended with other types of mixtures through human intervention.

    2

    Apparent Sucrose

    Not more than 5%

    Sucrose present in pure honey is little because enzymes present in honey (invertase) would be responsible for the breakdown of sucrose to fructose and glucose. High sucrose levels help to detect whether honey has been adulterated through:

    • adding cheap sweeteners such as cane or refined sugars

    • feeding bees with sugar instead of collecting nectar from Mānuka flowers
    • heating as heating causes invertase enzyme to denature thus unable to break down sucrose into glucose and fructose

    3

    Ash

    Not more than 0.6%

    Ash values depend on the mineral content of honey and measures the total residue remaining after incineration. High ash values may help to detect if honey was adulterated with high fructose corn syrup (HFCS) or blended with other types of honey.

    4

    Colour

    Grade 1 – As tested Pfund

    Colour helps characterise honey from different origins. Mānuka Honey is known for its creamy to dark brown hues, signalling its strong, distinctive flavour. Samples are heated to dissolve sugar crystals and then thoroughly mixed before analysis. The sample is clarified and a spectrophotometer is used to measure the colour.

    5

    C4 Sugar

    Not more than 7%

    Sugar in plants is produced by distinct biochemical processes during photosynthesis. Cane sugar and high fructose corn syrup (from maize) consist of C4 sugars. This test is to detect whether honey has been adulterated by adding sugar (mainly cane sugar and high fructose corn syrup) or if C4 sugars have been used for feeding of honey bees.

    6

    Diastase

    Not less than 8 – schade / g (rate of diastase activity)

    Diastase (alpha amylase) is an enzyme to convert starch to dextrins and sugars, the enzyme is introduced into honey by bees however there is no starch in nectar. In this test, honey is diluted in water, which releases the enzyme and allows it to perform its intended function. Starch is added to the sample where the diastase breaks up into glucose molecules. The speed at which this occurs is measured and is referred to as Diastase activity (DN). Diastase degrades over time, and is deactivated especially when exposed to heat. This test is then used to indicate that honey has been exposed to heat if diastase activity is low.

    7

    Dihydroxyacetone
    (DHA)

    As tested – mg / kg

    Dihydroxyacetone (DHA) converts to Methylglyoxal (MGO) during the honey production process. The Unique Mānuka Factor Honey Association (UMFHA) established guidelines for Mānuka Honey stating that both DHA and MGO should be present in products characterised as New Zealand Mānuka-type honey.

    8

    Foreign matter

    Free of an 80 mesh

    Foreign matter such as glass, wood or metal fragments may be introduced during the manufacturing process or may include matters related to honey such as body parts of bees or pieces of propolis

    9

    Free acidity

    Not more than 40 meq / 1000g

    Free acidity is the sum of all free acids present in honey (organic acids such as gluconic acid, citric acid etc) and inorganic ions (phosphates, sulfates and chlorides etc). Free acidity is the key factor responsible for the honey’s taste. However, acidity or pH level (together with moisture content) in honey may affect the development of yeast and mould in honey, thus higher value of free acidity may be indicative of fermentation of sugars into organic acids.

    10

    HydroxyMethylfurfural (HMF)

    <40 mg / kg

    Honey contains fructose. HMF is produced from the breakdown of sugar (fructose) in the presence of an acid and heat increases the speed of this reaction. If the honey was adulterated with addition of sugar, the action is also always coupled with thermal / heat treatment to produce a homogenous mixture to sell it as pure honey to consumers. Hence, increased HMF levels is used as an indicator to detect if honey underwent heat treatment / overheating, prolonged storage at high temperatures or direct adulteration.

    11

    Leptosperin

    >100mg / kg

    Leptosperin’s stability (concentration remains over time) and unique presence in Mānuka nectar makes Leptosperin an ideal marker to identify the authenticity of Mānuka Honey. This is because Leptosperin is very difficult to synthesize, thus its presence or lack thereof has the advantage to detect whether honey comes from Mānuka nectar.

    12

    Methylglyoxal
    (MGO)

    >than label
    mg / kg

    Methylglyoxal is created over time from the interaction of Dihydroxyacetone (DHA) in the honey with various naturally-occurring proteins and amino acids. A Mānuka Honey sample with a high DHA concentration has the potential to turn into a Mānuka Honey with higher MGO concentration than a comparable Mānuka Honey sample with a low DHA concentration.

    13

    Moisture Content

    Not more than 17.8%

    Moisture is the measurement of water in honey. Honey with a moisture content that is above 17.8% has an increased risk of fermentation. A yeast test may be performed on honey with high moisture to investigate the risk further. This is because the higher the water content in honey samples, the higher the survival rate of the yeast in honey, and hence the higher the fermentation activity which indirectly leads to the increase of acidity of honey.

    14

    Non-Peroxide Activity (NPA)

    As tested - % w/v phenol eq

    The antibacterial activity for most honey is primarily due to the presence of hydrogen peroxide (H2O2). However, in 1981, Professor Peter Molan of Waikato University, New Zealand discovered a distinctive antibacterial element in Mānuka Honey that was non-peroxide. Mānuka Honey uniquely displays additional antimicrobial activity due to the presence of Methylglyoxal (MGO). NPA results serve to support the labelling claims on the potency of the product.

    15

    Tutin

    < 0.70 mg/kg

    Tutin is a neurotoxin, present in the sap, leaves and seeds of the New Zealand Tutu plant (Coriaria arborea). Tutin isn’t toxic to bees but contaminates honey when bees collect honeydew excreted by the insect “passion vine hoppers” (Scolypopa Australis) that feeds on the Tutu plant. However, Tutin is poisonous to people and other mammals. Symptoms of Tutin ingestion in people ranges from mild (giddiness) to severe (coma and death). The Ministry of Primary Industries New Zealand (MPI) has established a maximum residue of 0.7 mg/kg of Tutin in honey as a food safety regulation to ensure toxic honey is not ingested by consumers. It is now a legal requirement in New Zealand that all honey for sale or export must comply with these regulations.

    16

    Water insoluble solids

    Not more than 0.1%

    These are impurities within honey that cannot dissolve in water. Typical insoluble impurities are wax, sand, clay and are found usually due to cross contamination or poor filtration.

     

     

    Mānuka Honey Markers

    All exported Mānuka Honey marketed or labelled as New Zealand Mānuka Honey are legally required to have the honey tested using the approved MPI test which analyses 5 key markers of the honey. The identified 5 chemical markers are always present in Mānuka Honey and are stable, thus reliable. This classification standard is designed to classify Mānuka Honey into two grades - Monofloral Mānuka Honey and Multifloral Mānuka Honey.

    If the honey fails one or more of the requirements it cannot be classified as Mānuka honey.

    4-HPLA, 2-MBA, 2-MAP and 3-PLA were selected based on a comprehensive analysis of their specificity, amount detected and thermal / storage stability (4°C, 20°C and 35°C for 68 days).

     

    No

    Test

    Reference Value

    Description

    17

    DNA from Mānuka Pollen

    < Cq 36

    The Mānuka DNA marker is a portion of plant DNA which has been shown to be unique to Mānuka plants. The DNA test is to differentiate between pollen from Mānuka and pollen from other plant species, including Kānuka a pollen. This test confirms that there is sufficient pollen from the Mānuka plant in the honey for it to be regarded as Mānuka honey. 

    18

    4-hydroxyphenyllactic acid (4-HPLA)

    ≥ 1mg/ kg 

     A naturally occurring compound found in Mānuka honey that MPI chose to confirm that a honey contains sufficient Mānuka nectar to be labelled as Mānuka honey.

    19

    2-methoxybenzoic acid (2-MBA)

    ≥ 1mg/ kg 

     A naturally occurring compound found in Mānuka honey that MPI chose to confirm that a honey contains sufficient Mānuka nectar to be labelled as Mānuka honey.

    20

    2-methoxyacetophenone (2-MAP)

    ≥ 5mg/ kg (monofloral)

    ≥ 1mg/ kg (multifloral)

     A naturally occurring compound found in Mānuka honey that MPI chose to confirm that a honey contains sufficient Mānuka nectar to be labelled as Mānuka honey.

    21

    3-phenyllactic acid
    (3-PLA)

    ≥ 400mg/ kg (monofloral)

    ≥ 20mg/ kg (multifloral)

     3-Phenyllactic acid (3-PLA) is the key differentiator between mono-floral Mānuka Honey and multi-floral Mānuka Honey. It may be that there is some correlation between higher levels of 3-PLA and higher Non-Peroxide Activity (NPA), but this is yet to be proven. 

     

     

    Microbiology test

    No

    Test

    Reference Value

    Description

    22

    Aerobic Plate Count

    < 10 000 cfu / g 

    The aerobic plate count measures the total number of aerobic organisms (bacteria that can survive and grow in an oxygenated environment) in honey. Bacteria may be introduced into the hive from bees, dust, dirt or during processing but bacteria’s growth is inhibited due to antimicrobial properties of honey. This microbiological test is to quantify bacterial contamination throughout the production process (collection, processing and packaging) and indicate the sanitary conditions under which honey was produced or processed. 

    23

    Escherichia coli

    < 10 cfu / g

    Escherichia Coli (E.Coli) is a major species in the faecal coliform group. E.Coli can cause serious illness in humans when ingested from contaminated food sources. This test is done to ensure safe consumption of honey.

    24

    Total Coliform

    < 10 cfu / g

     Total coliforms include bacteria that are found in the soil, in aquatic environments and on vegetation. They are also present in large numbers in the faeces of warm-blooded animals. Coliforms do not normally cause serious illnesses but are easy to culture, their presence are used to indicate that other pathogenic organisms of faecal origin that can cause diseases may be present.

    25

    Yeast and Moulds

    < NMT 1000 cfu / g

     Osmophilic yeast (microorganisms adapted to environments with high osmotic pressure such as high sugar concentrations) have a high tolerance to sugar levels and may contribute to the fermentation of honey. Significant levels of yeast and mould contamination can affect the flavour through fermentation of sugar into organic acids and appearance of honey.

    26

    Staphylococcus aureus

    < 50 cfu / g

     Staphylococcus aureus are bacteria that produces toxins which can lead to food poisoning. Large numbers of Staphylococcus aureus cells in food indicate that sanitation, temperature control, or both were inadequate.