Toxicity – Liver support

Toxicity is an unavoidable aspect of modern life and will affect the working of our bodies and cells. This is evident in the way we feel the day after we have consumed more alcohol than normal, watched a child have a moment of bad behaviour after consuming a packet of  brightly coloured sweets or realising that our ability to eat the same foods we did at 20 is not there any more at 50. For some folk, toxicity shows up in symptoms such as headaches that occur with prolonged exposure to a difficult person or intense electro-magnetic radiation. Like it or not there are toxins in our food, our water and the air we breathe without consuming any ‘bad stuff’.

In the Spring as new growth begins to show in nature, our bodies naturally move away from needing the fats to keep us warm on cold dark days and towards fresher tasting foods.  Whilst there is still little on offer to eat in the garden, during lent,  the Spring solstice on 21st March offers us a particularly good moment to shed some toxicity from the body built up over winter.

For some people giving up coffee and chocolate and drinking more water is enough of a detox; for others a vegan, sugar free, gluten free diet is ideal.  Whether you decide to take up fasting, bikram yoga and coffee enemas or just an extra daily walk around the park, I suggest that alongside any detoxification you do try and increase your intake of chlorophyll relative to other foods. My family are all having a green drink for breakfast during lent (recipe below).

The liver is the primary filter for all of the toxins, both those ingested orally (food/drinks) and emotionally in our bodies. It processes our stress and keeps the body balanced correctly to make all the body systems perform. Fasting conditions (or just a lack of the usual toxins) gives our liver a chance to process the fat cells and extraneous material that builds up over time.

One of the most important naturally produced antioxidants that helps the liver do its job is sodium dismutase. The internal availability of this antioxidant diminishes over time but can be supplemented,especially helpfully during detoxification period.  Green Bay’s green Wheat or Green Barley Grass powder is an easy way of achieving this and can be added easily in a small amount, to a jug of water with the juice of half a lemon and sipped as required. Personally, I like to enhance that the extra water consumed during a detox with a few electrolytes and minerals to increase the take up of nutrients.


Green Drink:

1/2 small glass apple juice

green leaves/cucumber/apple

1/2 banana, celery stick

Green Bay Green Barley grass powder 1 tsp

 Water to taste.

 Whizz in a jug and drink!


Here’s looking forward to a bouncy start to summer!

Wishing you very good health,


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Top 5 Mothers’ Day Breakfasts

1.Jo’s Green Smoothie.

Green-SmoothieTOTAL TIME: Prep: 15 min.

MAKES: 2-3 servings


  • Kale – 3 leaves without stalkes

  • 1/2 cup of apple juice

  • 1/2 cup of water

  • 1 teaspoon of maca powder

  • 1 pinch of organic fine kelp 

  • 1/2 banana or other sweet fruits

  • 1 hand full of salad leaves

  • Add Manuka Honey if required


  1. Whiz all the ingredients & dilute with water to taste.


2.Almond French Toast Hearts with Almond Butter


TOTAL TIME: Prep: 30 min. Cook: 5 min./batch

MAKES: 4 servings


  • 12 slices of bread

  • 4 eggs

  • 1/2 cup milk

  • 5 tbsp of Manuka Honey 

  • 1/2 tsp almond extract

  • 2 tbsps butter

  • fresh raspberries (or slices strawberries for garnish)

  • Manuka Honey (for serving)

  • 1/2 cup butter (softened)

  • 1/2 tsp almond extract (topping)


  1. Cut bread slices into heart shapes. You can use a large, almost 4 inch heart, cookie cutter or cut your own heart shape with kitchen shears. Use trimmings for another purpose.

  2. In a shallow bowl, whisk together eggs, milk, and 1/2 tsp almond extract (up to your taste).

  3. In large skillet, melt 2 Tbsp butter. Dip both sides of each bread heart into the egg mixture and place on the hot skillet. Cook each side for 2-3 minutes until golden brown.

  4. For the almond butter – in a small bowl, blend together the ½ cup butter, 2 Tbsp of Manuka Honey and ½ tsp almond extract.

  5. Serve cooked french toast with the almond butter along with fresh raspberries or strawberry slices. Drizzle with Manuka Honey. Serves 5-6.


3.Bacon and Cheese Egg Muffin Cups

bacon and cheese eggTOTAL TIME: Prep: 40 min.

MAKES: 6 servings (6 eggs)


Muffin Tin (by 6)

6 slices of bacon, not microwaved, just right out of the pan or grill

1/2 Cup shredded cheddar cheese

6 large eggs

Pinches of kosher salt and fresh cracked black pepper



1.  Preheat oven to 350 degrees F.  Press English muffins carefully into bottom of a 6 cup muffin tin.  Form a little circle with the bacon and place around inside of muffin.  Sprinkle inside with cheese then top with a whole egg in each cup, keeping inside the bacon ring.  Sprinkle with pinches of kosher salt and pepper.  Bake for 15-20 minutes or until egg is cooked through.

2.  Remove and let cool for 5 minutes before removing from muffin tin. Serve.

4.Jo’s Birches Muesli

brulee_oatmeal_recipeTOTAL TIME: Prep: 10 min + 1 night on the fridge

MAKES: 1 bowl


  • 1 cup apple juice

  • 2 cups organic oats

  • 1 cup creamy yoghurt or rice milk

  • 2/5 cup of nuts roughly chopped (hazelnuts/almonds/walnuts)

  • 1/2 teaspoon of cinnamon

  • 1 teaspoon of Manuka Honey

  • 1/4 cup of Flax fibre

  • 1 cup coarse grated apple/pear


  1. Soak all the ingredients (except the apple/pear) in a bowl overnight on the fridge

  2. Add the cup of apples or pears before serving with berries.


5.Pain Perdu


TOTAL TIME: Prep: 25 min + 1 night on the fridge

MAKES: 4 servings


4 1-inch thick slices country bread
1 quart thick cream
9 eggs
3 spoons of Manuka Honey
2 teaspoons kosher salt
1/4 cup unsalted butter
(1/2 cup brandy if you wish)
(some Manuka Honey on the top).


  1. Place bread in a large bowl and set aside.
  2. Mix cream, eggs, Manuka Honey, (brandy) and salt in a blender. Pour over bread slices.
  3. Cover with plastic wrap and refrigerate overnight, turning once to ensure proper absorption.
  4. Preheat oven to 350º F. Heat large oven proof saute pan over medium-high heat and add butter. When foam subsides, put soaked bread in pan and cook on one side, 5 minutes. Turn and place in oven, 10 to 15 minutes, until cooked through and custardy in the middle.
  5. Add Honey on the top.

Have a great breakfast!

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Honey and Manuka Honey ‘best before’ date

Our local Cambridge Health food owner has a family home in India where they keep some of their honey for more than four years to use when they get ill. Honey, if pure and well stored, does not go off.  It is said that the honey found in Yuaa and Thuaa‘s tomb (lovely cool dark place) was good, after 3300 years!


Young Egypt has a well-developed sweet tooth:
The ancient Egyptians were likewise fond of sweets. One of the most remarkable finds ever made by archeologists was a jar of honey, still liquid and still preserving its characteristic scent after 3,300 years, in the tomb of Yuaa and Thuaa, the parents of Queen Tiyi.


237aG_C2724Green Bay’s Manuka honey is of the best quality and packed by careful and caring producers that will ensure its longevity.  The best temperature to store honey is under 5 degrees and in the near dark ( a cupboard is ideal) as light will denature the honey slightly.

The ‘best before’ date that we are obliged by law to put onto the product is a date by which we estimate that the honey, if kept on a shopkeepers shelf in the light, might begin to lose quality.  Over time our honey will increase in activity rating and faster at higher temperatures, however if kept in a temperature over 40 degrees C. will also start to increase the bitter flavours in the honey. The ‘best before’ date on the bottom of the jar is not synonymous with ‘use by date (read article from the UK Government).

From February 2014, we have decided to cream our Manuka honey (article about creamed honey) to prevent the formation of large crystals that naturally occur over time if the honey is kept in a kitchen cupboard. If you do have honey that has crystallised, it is of course fine to gently warm it to melt the crystals and then keep it in the fridge, especially if your kitchen is warm.

Please continue to enjoy your Green Bay honey as the years go by, whenever it was purchased; we are confident that it will be delicious.

sigJo (3)

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Manuka Honey “Fake Labelling” issues

Many of you heard about the the problem of Fake Manuka Honey on the market and we wanted to give you and summary of what happened:

August 2013:

nikki kayeThe New Zealand Food Safety Minister Nikki Kaye told Radio New Zealand that an international standard was needed for New Zealand’s distinctive manuka honey, which is prized for its allegedly unique health properties and sells at a premium around the world.

But the United Kingdom Food Standards Agency has issued a warning about misleading claims made on jars of some honey products, and New Zealand honey exporters say more manuka honey is being sold worldwide than New Zealand produces.  The main honey suppliers’ organisation in New Zealand believes 1,700 tons of manuka honey are produced there every year, but 1,800 tons are being sold in the UK alone.

And they estimated that 10,000 tons of what is supposed to be manuka honey are sold around the globe, suggesting that consumers are paying premium-level prices for misleading products.


Kaye said she understood a meeting was being held this week between honey industry representatives and officials, and the Ministry for Primary Industries hoped to release the resulting guideline label standard over the next month.

The warnings from Britain about fake New Zealand manuka honey was more bad news for New Zealand’s brand reputation.

The Ministry for Primary Industries had failed to step in when the industry acknowledged New Zealand was selling more manuka honey than it produced, Labor primary industries spokesperson Damien O’Connor said in a statement.

Labor and the opposition Green Party called for the certified testing of manuka honey in government certified laboratories.

“The solution to this recent issue is to set government regulations for manuka honey to be exported in properly labeled retail packs that have been through government certified testing,” Green Party agriculture spokesperson Steffan Browning said in a statement.

Ms Kaye said it needed to be done right because there was a huge opportunity for honey producers.

“People do want manuka honey and if we can get that label right then there is a huge opportunity to grow the industry.”

September 2013:

Minister announces manuka honey consultation

Food Safety Minister Nikki Kaye announced consultation has begun to define manuka honey to enable truth in labelling.

“The Ministry for Primary Industries (MPI) will be asking the honey industry, scientists and other interested stakeholders for their say through this consultation process,” Ms Kaye says.

“The New Zealand honey industry has been working for many years to come up with an accurate way to label, market and brand manuka honey and unfortunately has been unable to reach consensus. There is no international standard for a definition of manuka honey.

“Recently, the authenticity of some New Zealand manuka honey has been queried in overseas markets. This puts the integrity of our country’s export reputation at risk and so steps need to be taken to ensure consumer confidence.

“It is important that New Zealand manuka honey label claims are correct and can be substantiated by science.”

The consultation document can be downloaded here: 2013-38-Proposals for NZ Manuka Honey Claims (1)



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How to start Meditation in a simple way?

Following a nice article about “10 Remarkable Ways Meditation Helps Your Brain”, you may wonder how to actually start meditation in a busy lifestyle?

Well after few research we found some simple tips to do that.

 Here’s a great infographic that gives an overview of the different kinds of meditation and some tips for fitting in meditation at work.

mediation infographic

In a more conventional way you will need to start with a correct set up, taking care of:

  • Posture
  • Eyes
  • Focus
  • The breath
  • Thoughts
  • Emotions
  • Silence
  • Length
  • Place
  • Enjoyment

Read more about the different points there:

A great app (Free) to start meditating just 10 minutes everyday with a guide: Headspace

The way it works is that Andy guides you through 10 minutes of simple meditation every day. You don’t have to do anything, just sit down and turn on the app and let Andy’s calm voice (his voice is truly amazing – the app is worth trying just for that!) explain to you how to approach meditation.

meditation app


We wish you great peaceful moments….


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What is Creamed Honey?

Beekeepers like to produce honey that is popular and the notion that honey, smooth and buttery, spread on toast is a justifiably delicious association with good honey. One of the easiest ways to achieve this is through creaming honey. The creaming process will inhibit the growth of crystals that may naturally occur in the honey and will instead encourage the growth of smaller crystals, thereby giving the honey the desired smooth texture.

The process is amazingly simple and will even work in your own kitchen. Take some fresh honey –  as runny as you like and gently warm it up around 40C, (temperature of the Hive) and introduce a little creamed honey or raw honey of a type that produces small crystals such as clover honey and stir. Leave it to cool down at room temperature for a week!

By giving clear honey smooth crystals it seeks to replicate them naturally. The term is ‘following suit’. The small crystals prevent the formation of larger crystals. It’s very similar to how yogurt and cheese are made, although they use cultures as seed.

Non drip creamed honey is great for kids as it is easy to spoon and not so messy.

At Green Bay we enjoy creamed honey from time to time. We have creamed our blackcurrant honey (coming January 2014) as the natural crystal formation is rapid and the crystals are large giving it a very grainy texture.

shop now button

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The in vitro effect of manuka honeys on growth and adherence of oral bacteria

The in vitro effect of manuka honeys on growth and adherence of oral bacteria



Honey has been used since ancient times and more recently, for the healing of wounds and against infectious diseases. The aim of our study was to investigate the effect of two manuka honeys showing different potencies of their antibacterial activity, on potentially pathogenic oral bacteria.

The antimicrobial activity was examined by determining the MIC and MBC using the macro dilution broth technique. The effect on the adherence was tested on growing cells of Streptococcus mutans on a glass surface and on a multi-species biofilm grown on saliva-coated hydroxyapatite discs.

As expected, the antibacterial activity of manuka Image (with higher potency of antibacterial activity) was the most important. The two tested honeys weakly inhibited the adherence of S.mutans cells to a glass surface at sub-MIC concentration.

Manuka Image showed a total inhibition of multi-species biofilm at the concentration of 200 μg/ml manuka Image inhibited biofilm formation weakly at the concentration of 200 μg/ml but firmly at the concentration of 500 μg/ml.

Our findings suggest that manuka honeys might be able to reduce oral pathogens within dental plaque. These two honeys appear to be able to control dental biofilm deposit.

Full research HERE.

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Identification and quantification of methylglyoxal as the dominant antibacterial constituent of Manuka (Leptospermum scoparium) honeys from New Zealand

Professor Thomas Henle and colleagues at The Technical University of Dresden publish the research results upon identifying the substance formerly known as the “unique manuka factor” primarily responsible for the non-peroxide activity of manuka honey.

January 2008
Molecular Nutrition Food Research


1 Introduction

The use of honey as a traditional remedy for bacterial infections is known since ancient times. According to [1], scientific research in that field aiming at the identification of antibacterial compounds started with the pioneering reports of van Ketel in 1892. Dold et al. [2] established the term “inhibine” for the light and temperature sensitive antibacterial substances in honey without further chemical characterization. Since then, numerous investigations have been undertaken in order to explain the antibacterial activity of individual honey samples by osmotic effects, or the low pH value caused by several organic acids [3–6]. The most known inhibine is hydrogen peroxide [7, 8], which is formed in the honey by glucose oxidase. Several studies, however, have shown that certain honey samples possess an antibacterial activity which persists after removal of hydrogen peroxide by catalase [8]. It has been observed that Manuka honey, derived from the Manuka tree (Leptospermum scoparium) in New Zealand, has a very high level of “nonperoxide” antibacterial activity [9–10]. The pronounced antibacterial activity of Manuka honey is an important commercial property, which is referred to in marketing purposes as the so-called “Unique Manuka Factor” (UMF), leading to a classification of premium products based on microbiological assays [11].

Although several studies have been undertaken in order to characterize the components responsible for the “non-peroxide” antibacterial activity of Manuka honey [12], the chemistry behind this phenomenon still remains unclear. In a recent report, Weigel et al. [13] showed that honey contains varying amounts of 1,2-dicarbonyl compounds such as glyoxal (GO), methylglyoxal (MGO), and 3-deoxyglucosulose (3-DG) besides 5-hydroxymethylfurfural, a wellknown indicator for heat-treatment. 1,2-Dicarbonyl compounds are formed in the course of the Maillard reaction or caramelization reactions as degradation products from reducing carbohydrates [14]. Motivated by a report from Suortti and Mlkki [15], who found that heated solutions of glucose or fructose, respectively, exhibit a pronounced antibacterial activity against Escherichia coli (E. coli), we investigated the hypothesis whether 1,2-dicarbonyl compounds present in Manuka honey may be related to the nonperoxide activity of these food items. 1,2-Dicarbonyl compounds were quantified after derivatization with orthophenylenediamine as the corresponding chinoxalines using RP-HPLC with UV-detection. Antibacterial properties of individual 1,2-dicarbonyls as well as of honey samples were evaluated using an agar well diffusion assay.


2 Materials and methods

2.1 Chemicals

GO and MGO, each 40% in water and MGO, were from Sigma (Taufkirchen, Germany). MGO was purified according to [16] with additional redistillation [17]. 3-DG was synthetized according to [18] with some modifications [19]. Acetic acid p.a. was obtained from BioChemica (Darmstadt, Germany). Phosphoric acid (85%, p.a.) was from Merck (Darmstadt, Germany). Orthophenylendiamine (OPD) was obtained from Fluka (Munich, Germany). HPLC grade methanol was from Riedel de Haen (Seelze, Germany). Water used for preparation of buffers and solutions was obtained with a Purelab plus purification system (USFilter, Ransbach-Baumbach, Germany). Agar agar, yeast extract, peptone, tryptone, and sodiumchloride were applied from AppliChem (Darmstadt, Germany).

2.2 Honey samples

A total of 50 honey samples of various origin were obtained from local retail stores or were received as a gift from Beekeeper’s association Dresden (Imkerverein Dresden, e.V.), respectively. The six samples of Manuka honey were ordered via the internet from suppliers of New Zealand honey.

2.3 Analytical RP-HPLC

1,2-Dicarbonyl compounds were analyzed as the corresponding quinoxalines after derivatization with OPD according to [13] with some slight modifications. 1.0 mL of 15% w/v solutions of honey in 0.5 M sodium phosphate, pH 6.5, or standard solutions of the 1,2-dicarbonyl compounds were mixed with 0.6 mL of a 1.0% w/v solution of OPD in 0.5 M sodium phosphate buffer, pH 6.5. The mixturewas kept in the dark for 12 h at room temperature. After membrane filtration (0.45 lm), 20 lL of this samples were subjected to chromatography analysis. This was performed using an kta Basic System with a pump P-900, UV monitor UV-900 and an auto sampler A-900 (all from Pharmacia, Freiburg, Germany). A stainless steel column, 250 mm64.6 mm, filled with Eurospher 100 RP18-material of 5 lm particle size (Knauer, Berlin, Germany), was used. The flow rate was 0.8 mL/min. The column temperature was set at 308C. The mobile phases were 0.15% acetic acid (solvent A) and 80% methanol containing 20% solvent A (solvent B). The gradient started with 20% solvent B over a period of 2 min, then it was changed linearly to 40% solvent B over a period of 20 min and to 100% solvent B within 15 min, followed by an elution with 100% solvent B over a period of 5 min and then it was changed to 20% solvent B in 7 min with subsequently equlibration with 20% solvent B for 5 min. Peaks were detected by measurement of UV-absorbance at 312 nm. External calibration using reference compounds in the range from 10 to 500 mg/L for 3-DG, from 0.1 to 20 mg/L for GO and from 0.1 to 300 mg/L for MGO was performed. All calibration curves showed linearity within these concentration ranges. Detection limits were 0.3 mg/kg for 3-DG and 0.2 mg/kg for GO or MGO, respectively.

2.4 LC/mass spectroscopy

LC-MS measurement was performed with a LC system 1100 Series (Agilent Technologies, PaloAlto, USA) and a Mariner ESI-TOF mass spectrometer (PerSeptive Biosystem, Framingham, USA). Chromatographic conditions were as above. Electrospray ionization was performed in the positive ionization mode. Nitrogen was used as curtain gas (1.5 L/min) and nebulizer gas (0.8 L/min). The mass spectrometer operating conditions were as follows: spray tip potential 5190 V, SCIEX heater 2908C, nozzle potential 90 V, skimmer 1 potential 11.50 V, quadrupole DC potential 7.50 V, deflection voltage –1.00 V, einzel lens potential –34 V, quadrupole RF voltage 1000 V, quadrupole temperature 1408C, nozzle temperature 1408C, push pulse potential 545 V, pull pulse potential 210 V, pull bias potential 3 V, acceleration potential 4000 V, reflector potential 1550 V, and detector voltage 2250 V. Full scan mass spectra were measured in mass range 100–3000 m/z in the tic-mode. The instrument was calibrated using a protein mixture containing bradykinin, angiotensin I, and neurotensin (Sigma–Aldrich, Steinheim, Germany). Data acquisition and handling was preformed using the software Data Explorer Version (Applied Biosystems, Foster City, USA).

Table 1. 1,2-Dicarbonyl compounds and HMF in honey samples and one pharmaceutical preparation (data given in mg/kg as median, minimum and maximum value; for samples of Manuka honey data are mean l SD resulting from triplicate analysis; abbreviations are as follows: 3-DG, 3-deoxyglucosulose; GO, glyoxal; MGO, methylglyoxal; HMF, 5-hydroxymethylfurfural; n.d., not detectable, below 0.2 mg/kg; n.a., not analyzed)

Table 1
Table 1

2.5 Assessment of antibacterial activity

Antibacterial activity of honey and solutions of 1,2-dicarbonyl were analyzed using an agar well diffusion assay according to Patton et al. (2005) [20]. E. coli or Staphylococcus aureus (S. aureus) were precultivated overnight at 378C in 50 mL flasks containing 10 mL of nutrient broth according to [21]. Afterwards 0.1 mL of the cultures were spreaded on plates containing solidified nutrient medium. Wells 10 mm in diameter (0.2 mL capacity) were bored into the surface of the agar medium. 0.15 mL of solutions of the 1,2-dicarbonyl compounds GO, MGO, and 3-DG in 0.5 M sodium phosphate buffer, pH 6.5, or honey diluted to concentrations ranging from 15 to 80% in the same buffer were placed into the wells. Plates were incubated at 378C for 20 h. The zones of inhibition were measured. MIC values (minimum inhibitory concentration) were determined. MIC corresponds to the lowest concentration, for which an inhibition zone was visually detectable.


3 Results

The trapping of 1,2-dicarbonyl compounds with orthophenylenediamine and subsequent chromatographic analysis of the corresponding chinoxalines using RP-HPLC with UV detection at 312 nm is a generally accepted method for the quantification the degradation compounds formed from carbohydrates during Maillard reactions or caramelization. Recently, we were able to quantify 1,2-dicarbonyls in honey [13] for the first time. In the present study, a large number of commercially available samples were investigated and it could be shown, that for most of the conventional honeys, the amount of GO and MGO was low when compared to 3- DG (Table 1). GO and MGO did not exceed maximum levels of 5 mg/kg and were not affected by storage conditions, whereas up to 1451 mg/kg of 3-DG were measured. The observation by Weigel et al. [13] that no correlation exists between the amount of HMFand 3-DG, the latter representing the direct precursor for HMF, could be confirmed.

Table 2. MIC (minimally inhibitory concentration) of solutions of 1,2-dicarbonyls or diluted honey samples, respectively, and concentrations of MGO in honey samples diluted to corresponding MIC

Table 2

While analyzing further honey samples, we noticed for samples of commercially available Manuka honey from New Zealand (Fig. 1A) surprisingly high peaks of a chinoxaline eluting with identical retention time as the chinoxaline formed from MGO and orthophenylenediamine (Fig. 1B). Using a photodiodearry detector, it could be shown that the UV-spectra of the peaks detected in the honey samples were identical to that in the reference sample of MGO. For unambiguous identification of the chinoxaline derived from MGO, LC-TOF-MS was performed. Identical mass spectra with a dominant signal at an m/z of 145.1 when measured as [MH]+ were found for the peak eluting at 39 min in the chromatograms of Manuka honey samples as well as the reference sample of MGO (Fig. 2). This clearly proves the unambiguous identification of the chinoxaline formed from MGO and orthophenylendediamine. In six samples of Manuka honey from New Zealand, concentrations for MGO ranged from 38 to 761 mg/kg (Table 1), which is up to 1000-fold higher than corresponding data for the conventional honey samples. Interestingly, there was an indication that the “UMF-value”, which is a commercially used parameter to rate the antibacterial activity of Manuka honey, is directly related to the content of MGO (Table 1).

Figure 1
Figure 1
Figure 2
Figure 2

Based on that surprising result, we hypothesized that the antibacterial activity of Manuka honey may at least in part be due to MGO. In order to prove this hypothesis, first the antibacterial properties of the 1,2-dicarbonyl compounds were evaluated using an agar well diffusion assay. As can be seen from Table 2, all compounds studied exhibited an inhibiting effect against E. coli and S. aureus. The pronounced antibacterial effect was found for MGO, which is expressed by a MIC value of 1.1 mM for both bacteria strains. The values for MIC represent the minimum concentration of a compound for which an inhibiting effect was detectable. GO, for which a MIC of 6.9 mM for E. coli and 4.3 mM for S. aureus were measured, and 3-DG, which showed no inhibition at concentrations up to 60 mM, were significantly less effective inhibitors for bacterial growth when compared to MGO (Table 2). Next, it was evaluated whether honey samples exhibit an antibacterial effect under the conditions used in our assay. A pronounced antibacterial activity was only found for the samples designated as “active Manuka honey”. For this samples, MIC values, expressed as concentrations after dilution in 0.5 M phosphate buffer, ranging from 15 to 30% were measured. All other honeys did not show any antibacterial effect in dilutions below 80%. Based on the quantitative data measured for MGO via RP-HPLC, it could be calculated that the amount of MGO “active” Manuka honeys diluted to the corresponding MIC, were similar to the determined MIC values of the standard solutions of the 1,2-dicarbonyl compound. In other words, diluting of Manuka honeys to concentrations between 15 and 30% resulted in concentrations of MGO from 1.1 to 1.8 mM, which are high enough to exhibit antibacterial effects.

This assumption was finally verified by adding the amount of pure MGO, which is present in a 20% solution of an active Manuka honey, to a 20% dilution of an “inactive” forest honey. This “inactive” honey did not show an antibacterial activity at a concentration of 20% (Fig. 3, sample 4), whereas for the sample of Manuka honey, an inhibition zone was clearly visible (Fig. 3, sample 1). This Manuka honey dilution contained 1.9 mM MGO. After adding 1.9 mM MGO to the 20% solution of the forest honey, an inhibition zone comparable to that of an active Manuka honey was visible (Fig. 3, sample 3). Based on this observation, it can be concluded the MGO present in Manuka honey is directly responsible for the pronounced antibacterial activity of Manuka honey.

Figure 3
Figure 3

4 Discussion

The fact that honey originating from the Manuka tree (L. scoparium) has a significantly higher level of antibacterial activity when compared to other honeys has been reported by several authors [9–11]. This antibacterial activity could not be explained solely by the enzyme glucose oxidase, which is present in honey originating from the bee, inducing the formation of hydrogen peroxide when honey is diluted [7, 12]. This additional contribution in antibacterial activity was referred to a “non peroxide activity” or “UMF”, and several attempts were made in order to identify the compounds responsible for this effect. Preliminary phenomenological studies showed that the compounds are heat and light stable, and are not affected when the pH value is shifted to values above 11 during fractionation procedures [5, 22]. Several antibacterial phenolic acids such as caffeic and ferulic acid as well as syringic and methylsiringic acid and flavonoids like quercetin, isorhamnetin, and luteolin [23–25] were identified. The concentrations of these compounds in honey, however, were far too low to cause antibacterial effects. Nevertheless, a patent published recently describes methods for the preparation of UMF fortified honey and methods for the preparation of UMF-containing fractions of honey without insight into chemical details [26].

With our findings, we unambiguously demonstrate for the first time that MGO is directly responsible for the antibacterial activity of Manuka honey. It is noteworthy that such high amounts of MGO as present in Manuka honey (Table 1) have not yet been found for any other food item. Low amounts of enzymatically formed GO and MGO were reported for fermented foods such as milk products as well as beer and wine, with concentrations ranging from 3 to 11 mg/kg [27, 28]. Furthermore, MGO is known to form during coffee roasting in amounts of 23–47 mg/mg [29]. Quantitative data for 3-DG in food are not available. At present, only speculations can be made concerning the origin of MGO in Manuka honey. A nonenzymatic formation via retro-aldolization in the course of heat- or storageinduced Maillard or caramelization reactions [14] can be excluded, as relatively low amounts of HMF were measured. HMF is a sensitive indicator for heat-treatment. MGO is known as a by-product of increased glycolysis in bacteria [30], therefore a microbiological origin of the 1,2-dicarboynl compound should be taken into account. Furthermore, a recent report [31] for the first time demonstrated the estimation of MGO level in the range of 30–75 lM in various plant species and its increase in response to salinity, drought, and cold stress conditions. Whether this may be of importance for Manuka from a botanical point of view remains to be elucidated. Further studies must also clarify whether the promising experience in wound care issues reported for Medihoney, which is a pharmaceutical preparation of Leptospermum honeys from Australia certified for wound care, may directly be due to MGO [32] ( One commercially available pharmaceutical sample of an antibacterial wound dressing contained 312 mg/kg MGO (Table 1). This concentration of MGO should be high enough to cause antibacterial effects when applied to wounds.

Finally, from the nutritional standpoint, the physiological significance resulting from the uptake of MGO and other 1,2-dicarbonyl compounds must be a topic of further investigations. MGO and glycation compounds resulting from the reaction of MGO with amino acid side chains of lysine or arginine, respectively, have been identified in vivo and are associated with complications of diabetes and some neurodegenerative diseases, although the role of these compounds in the pathogenesis of different diseases have not yet been fully understood [33–35]. Information concerning a potential toxicity of dietary MGO are rare and ambivalent, as the intake of MGO has also exerted an anticancer effect [35–37]. The physiological implications resulting from an uptake of bioactive carbohydrate degradation products and a risk-benefit analysis resulting there from must be topic of further investigations.

In conclusion, with the present investigation the occurrence of high amounts of MGO in New Zealand Manuka (L. scoparium) honey was demonstrated. MGO was identified as a bioactive compound which is responsible for the antibacterial activity of these honey samples. Studies in order to clarify the pathways for the biochemical formation of MGO in Manuka plants and honey are underway in our laboratory.

Full Article (pdf): henle_molecular_nutrition_2008

5 References

[1] Dustmann, J. H., Antibacterial effect of honey. Apiacta 1979, 14, 7–11.
[2] Dold, D., Du, D. H., Dziao, S. T., Nachweis antibakterieller, hitze- und lichtempfindlicher Hemmstoffe (Inhibine) im Naturhonig. Z. Hyg. Infekt. 1937, 120, 155–167.
[3] Dustmann, J. H., ber den Einfluss des Lichtes auf den Peroxidwert (Inhibin) des Honigs. Z. Lebensm. Unters. Forsch. 1972, 148, 263 –268.
[4] Bogdanov, S., Characterization of antibacterial substances in honey. Lebensm.Wiss. Technol. 1984, 17, 74–76.
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Abbreviations: 3-DG, 3-deoxyglucosulose; GO, glyoxal; MGO, methylglyoxal; OPD, orthophenylendiamine; UMF, Unique Manuka Factor

Copyright 2008 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim

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High-throughput microbial bioassays to screen potential New Zealand functional food ingredients intended to manage the growth of probiotic and pathogenic gut bacteria

A spectrophotometric bioassay was used to screen selected food ingredients intended for development of functional foods designed to influence the growth of gut bacteria.

September 2008
International Journal of Food Science and Technology

A spectrophotometric bioassay was used to screen selected food ingredients intended for development of functional foods designed to influence the growth of gut bacteria. Dose–response profiles displaying Δgrowth, the magnitude of deviation from growth of controls, were generated for probiotics Lactobacillus reuteri, Lactobacillus rhamnosus, Bifidobacterium lactis and pathogens Escherichia coli, Salmonella Typhimurium and Staphylococcus aureus. Ingredients were manuka honey UMF™20+(dose-dependently increased probiotics and decreased pathogens); bee pollen (biphasic growth effects against all); Rosehips and BroccoSprouts® (increased all dose-dependently); blackcurrant oil (little effect) and propolis (inhibited all strains). Ingredients were also bioassayed in pairs to assess desirable or undesirable synergistic interactions. Observed synergies included manuka honey (predominantly desirable); rosehips or BroccoSprouts® (desirable and undesirable); blackcurrant oil (desirable) and propolis (tended towards synergies reinforcing its antimicrobial effects), collectively revealing a complex web of interactions which varied by ingredient and bacterial strain. Manuka honey was particularly effective at influencing gut bacteria. The surprising frequency of undesirable synergistic interactions illustrates the importance of pre-testing potential ingredient combinations intended for use in functional foods.

Research article:


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Research: Improving Antibiotic Activity against Wound Pathogens with Manuka Honey In Vitro

Rowena Jenkins, Rose Cooper
Centre for Biomedical Sciences, Cardiff School of Health Sciences, Cardiff Metropolitan University, Cardiff, United Kingdom


Following the discovery of synergistic action between oxacillin and manuka honey against methicillin-resistant Staphylococcus aureus, this study was undertaken to search for further synergistic combinations of antibiotics and honey that might have potential in treating wounds.

Fifteen antibiotics were tested with and without sublethal concentrations of manuka honey against each of MRSA and Pseudomonas aeruginosa using disc diffusion, broth dilution, E strip, chequerboard titration and growth curves.

Five novel antibiotic and manuka honey combinations were found that improved antibacterial effectiveness in vitro and these offer a new avenue of future topical treatments for wound infections caused by these two important pathogens.

Full Research HERE.

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