Biochemical reactions in honey and their biological effects
What it found
Honey's enzymes and other reactions produce hydrogen peroxide, methylglyoxal, HMF and brown pigments.
These products are behind much of honey's antibacterial, antioxidant and other biological activity.
What they found
Animal and lab studies
Short peptides
Proteases in honey break proteins into short peptides. Some of these peptides act as antioxidants, antimicrobials or antitumor agents, depending on their amino acids. A study of five honey samples from Saudi Arabia found short peptides that varied with floral origin and storage.
Methylglyoxal in Manuka honey
In Manuka honey, methylglyoxal comes from dihydroxyacetone in the Manuka flower nectar, which converts at 37 °C. Methylglyoxal is a major contributor to Manuka honey's antibacterial activity. Some studies report it has both tumorigenic and antitumor activity.
Studies in people and animals
HMF in honey
HMF forms non-enzymatically from glucose or fructose, and its levels rise with high temperature and long storage. Two studies found that honey stored or treated between 21 °C and 50 °C had lower HMF than fresh honey, because HMF breaks down faster than it forms in that range. HMF has both negative and positive effects on human health, and its toxic level for humans is not yet clarified.
Other findings
Hydrogen peroxide in honey
Glucose oxidase, an enzyme from bees, turns glucose into gluconic acid and hydrogen peroxide. Catalase and other enzymes, plus vitamin C, break hydrogen peroxide down again. Honeys with high glucose oxidase and low catalase tend to have more hydrogen peroxide.
Antibacterial activity
Most of honey's antibacterial activity comes from hydrogen peroxide, its high sugar concentration and its low pH. Hydrogen-peroxide-producing honeys are used in wound and burn dressings.
Maillard reaction and browning
The Maillard reaction between sugars and amino acids produces brown pigments called melanoidins. These products act as antioxidants and antibacterial agents. Manuka honey samples had high levels of Maillard reaction products.
What the authors conclude
“From the researched literature, it is obvious that honey is very safe for human consumption.”
Also in their conclusions
- They say this review summarized, for the first time, the biochemical reactions in honey, including enzymatic and non-enzymatic reactions.
- They state that the substrates, intermediates, and products of these reactions are major contributors to the biological activities of honey.
- They also say that from the researched literature, it is obvious that honey is very safe for human consumption.
How it was done
The authors wanted to bring together the enzyme-driven and non-enzyme reactions that happen in honey, because these reactions affect its quality and biological activity.
They reviewed published studies on the chemical reactions in honey, including the substrates, intermediates and products involved. They also looked at how these products relate to honey's biological activities.
What it can’t tell you
- This is a review of other studies, so it does not present new experiments of its own.
- Many of the biological effects described come from lab tests or animal studies, which cannot show what happens in people.
- The toxic level of HMF for humans is not yet clarified.
Who paid
- Funding
- Funded by Research Center for Material Science at King Khalid University (from the PubMed record).
- Conflicts
- The authors certify that there are no conflict of interest with any financial organization regarding the material discussed in the manuscript.
- Authors work at
- King Khalid University, Saudi Arabia; Umm Al Qura University, Saudi Arabia; Omdurman Islamic University, Sudan
The paper
- Title
- Biochemical Reactions and Their Biological Contributions in Honey
- Type
- ReviewThe authors read earlier studies and describe what they found. It isn’t a new study.
- Evidence
- Studies in people · animals · lab
- Summarised from
- Full text
- Cite
- Alaerjani WMA, Abu-Melha S, Alshareef RMH, et al (2022). Biochemical Reactions and Their Biological Contributions in Honey. Molecules (Basel, Switzerland). doi:10.3390/molecules27154719Free full textPubMed 35897895DOI
Summary written 26 Sep 2026. Check it against the paper before it changes what you eat. How we summarise papers · Report an error