Quality is a pertinent aspect for market access for commodities. Food commodities especially, have strict quality requirement for them to access markets given their potential to impact on human health. Honey is a rare high value product that command premium prices in most market and should therefore be assessed against strict quality requirement. Most honey markets like the EU market have prescribed quality requirements that must be met in order to access the market. As a nutritional as well as a medicinal product, the effectiveness and efficacy of honey for the stated roles lies within a narrow compositional boundary which must not be breached.
Inherent in its bio-chemical make up is the antibacterial property, reducing the possibility of microbial contamination of honey. It is however vulnerable to contamination or quality breaches from a variety of other sources. Chemical contamination in terms of pesticides and antibiotics, contamination by trace elements and heavy metals, and noxious plant chemical elements can all be traced to the bee foraging environment. Super-normal moister content, hygiene and color distortions, and excess HMF (Hydroxy-methyle-furfural) levels can be traced to poor handling and miss applied management practices. Other sources of honey quality concern include intentional dishonesty under which unscrupulous individuals adulterate honey with sugar, molasses, corn syrup etc with the intent of deceptively selling the product out as honey. Over-feeding bee colonies with sugar syrup especially during late colony build up or honey flow seasons may also result in bees preserving the syrup in combs in form of honey. Bees foraging on sugarcane syrup (especially after cane harvest) are also likely to store the syrup in the combs and produce honey high in sucrose content.
Given the foregoing possibilities, it is very important serious consideration is given to honey quality so that consumers are supplied with authentic high quality honey that meet their expectation and protect them from unnecessary health hazards. In this post I will delve into salient honey quality issues with a view of keeping you well-informed on honey quality
How safe is honey then?
Honey is rich in nutritional and medicinal qualities and can be utilized in different ways to meet the needs of different categories of clientele when used either externally and internally. Given its chemical composition and inherent opportunistic components (e.g. pollen), honey may sometimes exhibit allergic reactions in different individuals. In as much as this may be normal, availability of contaminants in honey or sub-optimal quality status is likely to intensify negative effect and may in some cases lead to acute or chronic health impacts or even resistance to antibiotics (in case of antibiotic availability in honey). International systems of honey trade have therefore set quality parameters to be met for honey to be accepted in the markets. Different regions and marketing blocks e.g. the EU have strict quality requirement with prescribed minimum residue limits (MRLs) for chemical substances in honey.
Adherence to honey quality is a primary national government concern in most jurisdictions, governments at national or federal levels have developed national honey standards through their respective quality standards bodies. Regional and trading blocks have also developed quality standards reflective the long term average quality parameters for honeys harvested ins such regions under standard management practice. The standards provide guidance e.g. on acceptable moisture content, sugar content etc. Under such jurisdictions, accredited laboratories are identified where honey samples are sent for analysis to determine composition. Deviation from the acceptable honey quality standard leads to failed test result normally accompanied by disqualification from market access.
Market transparency and ease of follow up requires accurate traceability criteria for honey. Countries therefore implement national residue monitoring plans (RMPs). These plan provide detailed procedures for following back the honey to its production source, batch number date harvested and the environmental circumstances under which it was harvested. It also provides details on laboratory analysis results and the testing laboratory or institution. Competence or qualification of laboratories and staff are never under question because most honey testing is done in accredited laboratories with ISO/IEC 17025 Certification (a requirement of the RMP) making the results acceptable all over the world.
The aim of this section is to enlighten you on the honey quality issues but also to alley your concerns or doubts about quality and authenticity of honey whether it is locally produced and marketed or imported.
Bad honey – What causes poor quality?
There are environmental and management factors that contribute to compromised honey quality.
- When bees are foraging on flowers that have been sprayed – traces of pesticides in nectar and pollen of the flower is likely to be transferred by the foraging field bees into the hives. This is likely to end up in honey and may raise residue limits above acceptable levels. It is therefore instructive that a keen beekeeper monitors and understands the foraging environment of the colonies to eliminate possible residue build up in honey. The beekeeper should also raise awareness to his neighbors about safe pesticide use and about the value of bees for crop pollination.
- When bees collect animal or human urine with traces of antibiotics
- Chemical substances used in the hive to control pests or treat diseases may also accumulate in honey
- Harvesting unripe honey – beekeepers should harvest combs that are at least three quarters capped. Harvesting uncapped honey leads to high moisture content which reduces the quality of honey and makes it susceptible to fermentation. Furthermore, moisture contents above 20% (depending on local honey quality standards) will fail the quality test.
- Inappropriate storage of honey – honey is acidic in nature and would naturally react with metallic elements (e.g iron) to form salts. Appropriate storage materials for honey include food grade plastic, stainless steel and aluminum. Drums used in honey export packaging are coated on the inside to prevent chemical reaction with honey. Storing honey in open containers leads to high moisture content, honey is hygroscorpic and will absorb water from the atmosphere leading to high moisture content.
- Over heating honey during processing – honey is a highly viscous substance rendering straining very difficult in its basal natural state. It is therefore necessary during processing or refining that regulated temperature increase is carried out. It should therefore be warmed (indirectly) to a temperature of about 45 to 50 degrees Celsius. This reduces the viscosity to a level that allows easy straining. During this process however, if overheating occurs, the simple sugars in honey are converted into a complex chemical substance called HMF (hydroxy-methyle-furfural). High concentration of this substance in honey causes honey darkening and smell of burnt honey. Any amount of HMF above 40ppm in honey sample leads to failed test. It is also the substance used to measure honey freshness. The lower the level, the fresher the honey. Storage temperature above 25 degrees Celsius leads to increase in HMF levels.
Honey analysis – basic honey quality parameters
So how do laboratory technicians determine honey quality?
Honey quality standards prescribe thresholds for various parameters on which to base the test outcomes. In this section, I will briefly look at some basic parameters.
- Moisture Content – high moisture content causes fermentation, which is the only biological degradation process to which honey is susceptible. Honey naturally contains traces of yeast which remain dormant under the correct moisture content but is activated if the moisture content rises to certain levels. Should be below 20% inmost regions.
- Total reducing sugars (TRS) – the highest proportion of TRS is made up of glucose and fructose. There are however some traces of complex reducing sugars like maltose in varying quantities depending on the floral source of nectar. TRS content should be 65% and above for most honey standards around the world.
- Apparent sucrose – this parameter is used in estimating the amount of sucrose in honey. It should be below 5% for most of the honey standards.
- Acidity – natural honey is acidic with pH ranges between 6.5 to 3.5. Laboratories will accept acidic concentrations of 40ppm or below
- HMF – should be below 40ppm
- Heavy metals – tested using Atomic Absorption Spectrophometer (AAS) or Atomic Emmission Spectrophotometer (AES)
- Pesticides and amino acids – tested using High Pressure Liquid Chromatography (HPLC)
- Vitamins – tested using UV/VIS
Does honey color affect its quality?
Honey comes in a range of colors. The colors may range from colorless, white, amber, dark amber, dark, and even greenish.
The color is dictated by the floral source of honey and is never a quality indicator.
Different plant flowers give different honey colors and provided it is from a clean environment and is handled properly, it is just as good.
It is also worthy at this to note that different floral sources also produce differences in the organoleptic qualities of honey i.e. the qualities of taste and aroma.
The tastes may range from sweet to bitter honey. Certain flowers may also produce honey that is poisonous or honey with unexpected physiological effect e.g. the mad honey (Duzce region in Turkey).
Beekeepers should therefore be able to know the type of flowers in their locality and the type of honey they produce. This information should be fully disclosed to the buyer before purchase to avoid any unexpected outcome.
In Samburu County in Kenya at a location called for example Wamba for example, local beekeepers have identified a type of flower that produces a highly medicinal honey. The only negative effect is that this honey causes the consumer to pass out for about half an hour, but you wake up thoroughly revitalized.
The point here is to emphasize that different tree flowers produce different types of honey. Regardless of taste or effect, honey quality based on established parameters are not affected by the floral source.
Consumers are therefore advised to get as much information as possible about the honey they intend to buy in case it is some unique honey.
Crystallization – how does honey crystallize?
So your honey has crystallized, does this mean its bad?
Does this mean that its adulterated with sugar?
Is this a sign of expiry?
It is very normal and natural for honey to crystallize. Why? look at it very keenly, honey is the only solution in the world that contains extremely highly solute concentration yet remains in liquid state.
It is therefore a super saturated solution having an overload of invert sugars which would under natural circumstances tend to solidify.
Crystallization is therefore simply the formation of fine glucose crystals as glucose separates from water to form crystals.
What causes crystallization
The invert sugars in honey i.e. glucose and Fructose have different solubilities, fructose is more soluble than glucose therefore glucose has a higher tendency to solidify.
The equilibrium therefore between these two sugars play a big role in the process of crystallization and is the reason why honey from some plants crystallize faster than honey from other plants.
Where this equilibrium tilts in favor of glucose, the tendency to crystallize is higher than when the reverse is true.
There are however also some other factors that accelerate the rate of crystallization
- Temperature – honey does not crystallize in temperatures below 2 degrees Celsius and above 25 degrees Celsius. It crystallizes in the range of temperatures in between but optimal temperatures for crystallization is 12.5 degrees Celsius.
- Presence of pollen or dust particles in honey – these suspended particles in honey act nucleus to start the formation of crystals
- Slow stirring accelerates the process of crystallization
How to slow honey crystallization
- Storing honey at an appropriate temperature close to 2 degrees Celsius. Storing honey at temperature close to 25 degrees Celsius will cause high HMF content. This is why long term honey storage is done in cold rooms
- Use appropriate processing procedure e.g. pressure filtering to avoid suspended particles in honey
- Warm the honey to e temperature of 45 degrees Celsius, this affects the glucose fructose balance in honey
So is crystallization all bad?
On the contrary crystallization is good. The process of crystallization can be harnessed in the honey industry to produce creamed honey, a valued honey product of very high demand. Crystallized honey is also very stable in state and can be stored for a long period without losing its fragile qualities.
Honey quality is a very important consideration for honey marketing. I have endeavored to highlight briefly the main issues concerning this important topic. Consumer awareness in honey quality is more important now than never given the impact of our present choices on human and environmental health and their relation to future trends in sustainability.
I welcome your thoughts and comments on the subject covered in this post or on any related aspect of honey quality.
Should you have any further questions or any issue that may require clarification, don’t hesitate to contact me on firstname.lastname@example.org