Technical Glossary
A B C D E F G H I J K L M N O P Q R S T U V W X Y Z
Select the first letter of the word from the list above to jump to appropriate section of the glossary.
- A -
Antimicrobial Properties
The factors that may contribute to the antimicrobial properties of honey are:
- High osmotic pressure, low water activity (Aw)
- Low pH - acidic environment
- Glucose oxidase system - forms hydrogen peroxide
- Low protein content
- High carbon to nitrogen ratio
- Low redox potential (Eh), due to high content of reducing sugars
- Viscosity opposes convection currents and limits dissolved oxygen
- Chemical agents
- Pinocembrin
- Lysozyme
- Acids (phenolic)
- Terpenes
- Benzyl alcohol
- Volatile substances (possibly phytochemicals influenced by bee enzymes)
Antioxidants
Generally, darker honeys and those with higher water content have stronger antioxidant potential. The antioxidants identified thus far in honey are pinocembrin, pinobanksin, chrysin and galagin. Pinocembrin is unique to honey and found in the highest amount relative to the others. Ascorbic acid (vitamin C), catalase and selenium are also present.
- B -
- C -
Chemical Characteristics
pH and Acids
pH 3.9 Range: 3.4-6.1
Acids 0.57% Range: 0.17-1.17% (primarily gluconic acid)Proteins, Amino Acids, Isoelectric Point
Protein 0.266%
Nitrogen 0.043%
Amino acids 0.05-0.1%
Isoelectric point 4.3Analysis: Honey is chemically compatible with a wide variety of products. Its pH and isoelectric point are in a range common to many food systems.
Color
The colors of honey form a continuous range from water white to dark amber. The color of honey is related to its mineral content and is characteristic of its floral source. Light colored honey typically has a mild flavor, while dark colored honey is usually stronger in flavor.
The Pfund color grader is a device used by the honey industry to measure the color of honey. The respective color designations, applicable range of each color, color range on the Pfund scale and optical density of freshly prepared caramel-glycerin solutions (USDA method) are presented on the following table.
Color Designations
Color Name |
Pfund Scale (mm) |
Optical Density1 |
| Water White |
< 8 |
0.0945 |
| Extra White |
9-17 |
0.189 |
| White |
18-34 |
0.378 |
| Extra Light Amber |
35-50 |
0.595 |
| Light Amber |
51-85 |
1.389 |
| Amber |
86-114 |
3.008 |
| Dark Amber |
> 114 |
— |
1 Optical density (absorbance = 100/percent trans-mittance), at 560 nm for 3.15 cm thickness for caramel-glycerin solutions measured versus equal cell containing glycerin.
Cremed Honey: see whipped honey
Crystallization/Granulation
Crystallization or granulation is a natural process that occurs in honey. Honey is a supersaturated sugar solution out of which the glucose tends to crystallize. The glucose/water content ratio and presence of nuclei for crystal growth help to determine the rate of crystallization. Crystallization is most rapid at 57 °F (14 °C) and can be reversed by heating. Honey appears lighter in color after crystallization.
- D -
Diabetes
Diabetics must control their total intake of carbohydrates, not the type. Therefore, honey may be included in a diabetic diet. They must, however, comply with the medical regime and diet instructions prescribed by their individual healthcare providers to keep blood sugar levels under control.
Diastase
Also known as amylase (see ENZYMES).
- E -
Energy
Honey contains 64 calories per tablespoon.
Enzymes
The major enzymes present in honey are invertase (that converts sucrose into glucose and fructose), amylase (diastase) and glucose oxidase (that produces gluconic acid and hydrogen peroxide from glucose in diluted honey). Others, including catalase and acid phosphatase, may also be present.
The Major Enzymes Present In Honey
| Enzyme |
Function |
| Invertase |
Converts sucrose to glucose and fructose |
| Amylase (also known as diastase) |
Hydrolyzes starch to dextrins and/or sugars |
| Glucose oxidase |
Converts glucose to gluconolactone, which in turn yields gluconic acid and hydrogen peroxide |
Catalase |
Converts peroxide to water and oxygen |
| Acid phosphatase |
Removes inorganic phosphate from organic phosphates |
Extracted Honey
Honey that has been separated from the comb by centrifugal force, gravity, straining or by other means.
See U.S.D.A. Standards for grades of honey.
- F -
Fermentation
Fermentation in honey is caused by osmophilic yeasts. It will
not occur in honey that has a carbohydrate content > 83%, a moisture content < 17.1%,
a storage temperature < 52 °F
(11 °C) or that has been heat-treated. Properly extracted, treated
and stored honey should not ferment.
See USDA Standards for grades of honey.
Filtered Honey
Filtered honey is processed by filtration to remove air bubbles,
extraneous solids and pollen grains.
See USDA Standards for grades of honey.
Floral Sources
There are more than 300 floral sources for honey in the United States, including clover, alfalfa, buckwheat and orange blossom. Honey’s color and flavor vary with its nectar source.
Freezing Point Depression
15% honey solution: 29.44 to 29.25 °F (-1.42 to -1.53 °C)
A 68% honey solution freezes at 21.6 °F (-5.78 °C)
Functional Characteristics of Honey
- G -
Grading
Honey is graded, on a voluntary basis, using USDA standards. These standards are a point system based upon water content, flavor and aroma, clarity and absence of defects.
| Minimum Total Solids (%) |
Maximum Water Content (%) |
|
| Grade A |
81.4 |
18.6 |
| Grade B |
81.4 |
18.6 |
| Grade C |
80.0 |
20.0 |
Granulation
Honey is a supersaturated solution and glucose tends to crystallize
out of solution. The ratio glucose/water content and the presence of nuclei
for crystal growth are related to the rate of granulation. Granulation is
reversed by heating.
- H -
Heat Treatment / Pasteurization
Honey is heat-treated to prevent unwanted fermentation by osmophilic yeasts and to delay crystallization. One common heat treatment is 170 °F (77 °C) for two minutes followed by rapid cooling to 130 °F (54 °C). Other effective treatments include heating honey to 140 °F (60 °C) for 30 minutes or 160 °F (71 °C) for one minute or some straight line gradient between those two temperatures. Honey may be damaged by too much heat.
Hydroxymethylfurfural (HMF)
Hydroxymethylfurfural (5-hydroxymethyl-2 furalde-hyde), also called HMF, is a compound that results from the breakdown of simple sugars (such as glucose or fructose) at pH 5 or lower. HMF occurs naturally in honey, especially in warm climates.
- I -
Infant Botulism
Infant botulism is a rare but serious paralytic disease caused by the microorganism Clostridium botulinum. After ingestion, C. botulinum spores can germinate, grow and produce toxin in the lower bowel of some infants under one year of age. C. botulinum spores are widely distributed in nature. They can be found in soil, dust, the air and raw agricultural products. Honey is also a potential source of C. botulinum spores. Infants are susceptible to infant botulism until their intestinal microflora develop. Children and adults with normal intestinal microflora are able to ingest C. botulinum spores without harm. The National Honey Board, along with other health organizations, recommends that honey not be fed to infants under one year of age.
- J -
- K -
- L -
- M -
Microbiology
Honey has inherent antimicrobial properties that discourage the growth or persistence of many microorganisms. The microbes that may be found in honey are primarily yeasts and spore-forming bacteria. No vegetative forms of disease-causing bacterial spores have been found in honey. Because bacteria do not replicate in honey, if high numbers of vegetative bacteria were to be detected, it may indicate contamination from a secondary source.
Moisture Content
At most 18.6% for grades A and B, and 20% for grade C for extracted
honey in the U.S.
See USDA Standards for grades of honey.
- N -
- O -
Oligosaccharides
Medium-sized carbohydrates, containing more than three simple sugar sub-units, often made of mono- and disaccharides. Oligosaccharides are sometimes referred to as "higher sugars."
- P -
Pfund Color Grader
A device used by the honey industry to compare and grade the colors of honey.
Pollen
Very fine granular material that bees gather from flowers. Can be found in strained honey, but is removed by filtration (to improve clarity).
Processing
- Q -
Quality of Honey
A number of factors are considered including: flavor, aroma, clarity and
absence of defects.
See USDA Standards for grades of honey.
- R -
Refractive Index
The moisture, or conversely the soluble solids in honey, is determined by measuring the refractive index of honey using a refractometer. Because the refractive index of honey is different from that of a sucrose solution at the same concentration, a special moisture chart must be used. This chart is found in AOAC Method 969.38 (see Analytical Methods). Using the "Brix" or "Sucrose" scale will provide inaccurate values for honey.
Refractometer
Used to measure the soluble solids content of extracted honey.
Rheological Properties
Most honeys have Newtonian properties. However, a few honeys have thixotropic
properties (e.g., heather and manuka honeys) attributable to their relatively
high content of certain proteins. Dilatancy is noted with very few honeys
and is related to the presence of polysaccharides of high molecular weight.
- S -
Soluble Solids
Minimum total solids for filtered and strained honeys : 81.4% for grades
A and B, 80% for grade C.
See USDA Standards for grades of honey.
Specific Gravity
Dependent upon water content:
| Water Content (%) |
Specific Gravity (20 °C) |
| 15 |
1.4350 |
| 18 |
1.4171 |
Other factors such as floral source slightly affect the specific gravity of honey. Honeys from different origins or batches should be thoroughly mixed to avoid layering.
Specific Heat, Thermal Conductivity
The specific heat of honey is in the 0.54-0.60 cal/g/°C range for liquid honey, and is equal to 0.73 cal/g/°C for finely granulated honey.
The thermal conductivity of honey increases with temperature and total solids, ranging from 118 x 10 -5 to 143 x 10 -5 cal/cm sec °C.
Storage
The optimum storage temperature for honey is below 52 °F (11 °C) or in the 70-80 °F range (21- 27 °C), in air-tight containers.
Strained Honey
Strained honey has been passed through a mesh material to remove particulate matter normally found in unprocessed honey. The mesh, however, does not remove any pollen that may be in the honey.
See USDA Standards for grades of honey.
Sweetness Value
The sweetness value of honey is approximately equal to that of invert sugar.
- T -
Temperature of Storage
Optimum storage temperature is below 52 °F (11 °C) or in the 70
to 80 °F range (21 °C to 27 °C ), in air tight containers.
- U -
USDA Standards
Government standards define the grades for Comb Honey and Extracted Honey (filtered and strained styles; liquid and crystallized types).
- USDA Standards for Extracted Honey (in PDF format)
- USDA Standards for Comb Honey (in PDF format)
- V -
Viscosity
The viscosity of honey decreases rapidly as its temperature rises. 1% moisture is equivalent to about 3.5 °C in its effect on viscosity. The viscosity can be adjusted to fit any manufacturing delivery system.
- W -
Water Activity
Dependent on its water content, temperature, floral source and other factors, honey’s water activity varies between 0.5 (16% H 2 O) and 0.6 (18.3% H 2 O) in the 40-100 °F (4-37 °C) temperature range.
Weight
The weight of honey varies slightly with the moisture content. One gallon of honey weighs approximately 12 lbs.
Whipped Honey
Whipped honey is liquid honey processed by controlled crystallization to yield a product with a smooth, spreadable consistency. Also called "Creamed Honey," "Churned Honey," "Candied Honey" or "Honey Fondant."
- X -
- Y -
Yeasts
All natural honeys contain sugar-tolerant yeasts. They are destroyed by pasteurization.
- Z -
Zinc
One of the many minerals contained in honey.