Food Safety Magazine, August/September 2009

territorial or topographical origin, if the product comes entirely from the indicated source; specific quality criteria.” The EC is encouraging the development of harmonized analytical methods to permit the verification of compliance with the quality specifications for different types of honeys.

Among the compositional criteria prescribed in the existing EC honey directive are requirements relating to the concentrations of acidity, apparent reducing sugar ( calculated as invert sugar) and apparent sucrose, 5-hydroxymethylfurfural (HMF) content, mineral content (ash), moisture and water-insoluble solids.

Consumption of honey and honey products has grown considerably during the last few decades. However, at the present time, the traceability of this food is limited to the quality of each processor’s documentation. In case of doubt or fraud, there is no standardized analysis available that can discriminate or determine the botanical

“…the traceability of this food

is limited to the quality of each

processor’s documentation.”

(floral or vegetable) and geographical (regional or territorial) origin of the honey. Counterfeiting and product adulteration are now commonly practiced in the global food marketplace.

Because of its high nutritional value and unique flavor, the price of natural bee honey is relatively much higher than that of other sweeteners. Honey is susceptible to adulteration with cheaper sweeteners; those that have been detected in adulterated honeys include sugar syrups and molasses inverted by acids or enzymes from corn, sugar cane, sugar beet and syrups of natural origin such as maple. Adulteration of pure honey with synthetic honey (based on C4 plant sugars) has become much more prevalent in recent years. In addition, there has been a recent major adulteration problem in honey from the Far East.

It should be emphasized that the adulteration of pure honey is one issue and concern about the botanical and geographical origin of honey or its authenticity is another, but the two can overlap, as in the case of adulteration by honey of other geographical origin, from a country where quality measures are not as stringent and the honey price is much lower.

Many foods have the potential to be deliberately adulterated, but those that are expensive and are produced under wide fluctuations in weather and harvesting conditions are particularly susceptible; honey is one such material.

Adulteration usually refers to mixing other matter (substance) of an inferior and sometimes harmful quality with food or drink intended to be sold. With companies concerned about the bottom line, the temptation to cheat is considerable, and unfortunately, the adulteration of honey is a serious economic and regulatory problem. As usual, the losers are the consumers and the processor or re-processor seeking to provide a wholesome product that meets regulatory standards. From an economic point of view, food product adulteration can destabilize the market by bringing in unfair competition.

Authentication of pure honey is of primary importance for both consumers and honey processors. Additionally, honey processors do not wish to be subjected to unfair competition from unscrupulous processors who would gain an economic advantage by misrepresenting the honey they are selling.

Honey adulteration appeared on the world market in the 1970s when high-fructose corn syrup was introduced by the industry. As the sugars ( 60.7–77.8%) are the major components of honey and the most dominant are the monosaccharides fructose and

glucose (accounting for 85–95%), the actual proportion of glucose to fructose in any particular honey depends largely on the source of the nectar. The average ratio of fructose to glucose is 1.2:1. The amount of glucose in honey is usually at a supersaturated level at normal temperatures. With reduction in temperature or water content, the glucose can crystallize out. Saccharose (sucrose) is present in honey at approximately 1% of its dry weight. Normally, honey contains 12. 4– 24.5% moisture. Unless the moisture content is below 17%, no fermentation takes place.

The processing of honey includes controlled heating to destroy yeast and dissolve dextrose crystals, combined with fine straining or pressure filtration. Most honey will crystallize during some period of time unless action is taken to prevent it. Generally, when honey is stored below 10 °C, crystallization can be prevented or delayed.

Honey is usually warmed to a temperature of 32± 40 °C to lower its viscosity, which facilitates extraction, straining or filtration. This temperature is similar to that in beehives and does not affect the honey very much during the relatively short processing period. However, some honeys are heated to a higher temperature for liquefaction or pasteurization reasons.

Adulteration Detection

All food products targeted for adulteration are high-value commercial products, including honey. The detection of adulteration can pose a technical problem. The quality of honey is mainly determined by its sensorial, chemical, physical and microbiological characteristics. Analytical methods applied to honey generally deal with different topics: determination of botanical or geographical origin, quality control according to the current standards and detection of adulteration or chemical residues.

At present, a variety of analytical techniques have been developed to detect adulteration of honey, such as isotopic (stable isotope methodology), chromatographic, spectroscopic, trace elements techniques and thermal analysis.