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Microbes & Immunity Broad-spectrum health benefits of honey

2.2. High osmolality from 2 to 5. In an environment with a lower pH, enzymatic

Honey is a natural product comprising primarily of reactions proceed slowly. Glucose oxidase catalyzes the
glucose and fructose, with the sugar component typically conversion of glucose to gluconic acid, during which
accounting for approximately 80% of its total composition. hydrogen peroxide is produced (Figure 1). The glucose
This makes it a popular choice as a sweetener. The low oxidase is responsible for the generation of hydrogen
water content of honey, in conjunction with the high peroxide, which is a byproduct of the oxidation of glucose
osmotic pressure environment it generates, can result in to gluconic acid. The amount produced in honey is related
the dehydration of microbial cells, thereby disrupting the to the minimum inhibitory concentration of honey.
microenvironment within the cells. This impairs their However, due to the environmental effects, the hydrogen
normal physiological processes, preventing them from peroxide produced is not capable of exerting a strong
surviving and reproducing. The high osmotic pressure not antimicrobial effect. Therefore, the antimicrobial effect
only destroys the cellular structure of the microorganisms of honey is more reliant on its hypertonic environment
but also prevents the influx of water needed for bacterial and low water content. The amount of hydrogen peroxide
reproduction, thus further enhancing the antibacterial is not controlled by a single factor. Honey is rich in
effect of honey. The dual inhibitory mechanism, comprising polyphenolic compounds, and the auto-oxidation of
low water content and high osmotic pressure, is responsible polyphenols also produces hydrogen peroxide, which
for the antibacterial properties of honey. 22 enhances the antibacterial activity of honey. It has been
suggested that honey contains microorganisms such as
2.3. Moisture content Penicillium and yeast that also produce small amounts of
It has been demonstrated that water activity (aw) within hydrogen peroxide. 29
the range of 0.94 – 0.99 is capable of completely inhibiting 2.6. Phenolic compounds
bacterial growth. The average water content of honey is
23
30
17% and the normal range of water activity is between 0.56 Phenolic compounds are the main source of antioxidant
and 0.62, which does not provide favorable conditions for activity in honey and contain one or more aromatic rings
microbial growth thereby achieving bacterial inhibition. with multiple phenolic hydroxyl groups in their structure.
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Glucose and fructose have strong water absorption and Phenolic compounds reduce the level of reactive oxygen
can form hydrogen bonds with water molecules, and the species in cells and minimize a wide range of damage at
water therefore exists in a bonded state within honey. both the molecular and cellular levels. Phenolic compounds
The water content of honey is also affected by factors in honey mainly include phenolic acids (Figure 2) and
such as the harvesting season as well as the geographical flavonoids (Figure 3). It has been found that darker-colored
environment. 25 honey has a higher phenolic acid content than lighter-
colored honey and has better antioxidant capacity than
2.4. Protein content lighter-colored honey. Common phenolic compounds in
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The proteins in honey mainly include amino acids and honey include quercetin, kaempferol, apigenin, caffeic acid,
enzymes. There are 20 types of amino acids, of which and p-coumaric acid. The composition and concentration
proline is the most abundant, accounting for 50% of the of these compounds vary, depending on the floral source
total free amino acids in honey. Proline can undergo a of the honey, which influences its overall therapeutic
Maillard reaction with sugar, giving it a unique flavor. In and health benefits. These compounds also contribute to
addition to being involved in the Maillard reaction, proline honey’s flavor, color, and its ability to scavenge free radicals.
has antioxidant properties of its own, which can neutralize
free radicals and reduce cellular damage, thus achieving 2.7. Carbohydrates
antioxidant effects. Some studies have shown that proline Honey is predominantly composed of carbohydrates, which
can also promote wound healing and tissue regeneration. account for approximately 80% of its total composition,
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The main enzymes in honey are glucose oxidase, catalase, making it a rich source of quick energy. The majority
and acid phosphatase. Glucose oxidase releases of these carbohydrates consist of simple sugars, namely
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hydrogen peroxide when it acts on glucose, enhancing its glucose and fructose, 27,32-34 both of which are easily absorbed
antimicrobial and antioxidant properties. by the human body. These monosaccharides are rapidly
metabolized, providing an immediate and readily accessible
2.5. Hydrogen peroxide source of energy. Glucose typically makes up about 30%
Hydrogen peroxide is a class of oxidizing agent of the carbohydrate content in honey, while fructose
that typically inhibits the growth of bacteria and constitutes around 40%. This unique ratio of glucose and
microorganisms. The environmental pH of honey ranges fructose is responsible for the characteristic sweetness of
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Volume 2 Issue 2 (2025) 3 doi: 10.36922/mi.6592