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Research on donkey milk · Study 53
What lactic acid bacteria make of donkey milk: 679 peptides compared in the laboratory
A research team in Turin fermented pasteurised donkey milk with two lactic acid bacteria and examined the protein fragments – peptides – formed in the process. They were tested in the test tube and in cell culture and compared with unfermented donkey milk.
What it's about
Fermentation as protein scissors
During fermentation, lactic acid bacteria break milk protein down into smaller pieces, so-called peptides. Some peptides from cow's milk are well researched. For donkey milk, there have been few data so far.
The team from Turin – the same research group as for the FortiLat studies – tested five bacterial strains, selected the two strongest and compared their peptides with those from unfermented donkey milk.
What exactly was studied?
Briefly explained
Terms from the study
Short chains of amino acids formed when protein is broken down.
Transformation of milk by microorganisms, for example in yoghurt or kefir.
Counts the spots in a cell culture where viruses have destroyed cells.
Comparing peptides found with a database of known peptides – a prediction, not proof.
5 strains tested in donkey milk, 2 selected.
24 hours at 37 °C, without bacteria as a comparison.
Peptides purified and identified by mass spectrometry.
Radical scavenging, bacteria and virus tests in the laboratory.
Interactive · The data at a glance
From fermentation to laboratory test
How many peptides were formed, where they came from, what the laboratory tests showed – and how to interpret the virus test. Switch between the views.
0175350
050100 %
Values from the text of the freely available original publication. Individual values available only as a graphic are not shown.
Key findings
What the researchers report
Each strain cuts differently
679 peptidesThe three samples shared only a few peptides. Most were found after fermentation with L. rhamnosus. Most pieces came from β-casein. According to the database, 41 peptides resembled known bioactive peptides.
Slightly stronger radical scavengers
+25 % in the DPPH testPeptides from fermented donkey milk scavenged more free radicals in the test than those from unfermented milk. The growth of two bacterial species was only temporarily slowed.
Virus test without an advantage from fermentation
> 50 % in all samplesAll extracts inhibited the replication of herpes simplex viruses in cell culture – including the one from unfermented milk. No advantage of fermentation was seen here.
The authors see fermentation as a favourable way of releasing peptides from donkey milk. They themselves emphasise that the peptide profiles varied from batch to batch and that the database contains hardly any peptides from donkey milk.
Critical assessment
Interesting basics, not evidence of health benefits
What the study shows
What it does not show
Research question for DON DONKEY’S®
How does processing change the proteins in donkey milk?
The study shows how strongly processing can change the protein profile of milk. We are interested in what pasteurisation, freezing and drying do to the proteins in our donkey milk.
Original publication
Donkey Milk Fermentation by Lactococcus lactis subsp. cremoris and Lactobacillus rhamnosus Affects the Antiviral and Antibacterial Milk Properties
Original title of the publication.
Cirrincione S., Luganini A., Lamberti C., Manfredi M., Cavallarin L., Giuffrida M. G., Pessione E.
Molecules · 2021 · volume 26, issue 16, article 5100 · open access
CNR-ISPA Grugliasco · University of Turin · University of Eastern Piedmont (Novara)
DOI: 10.3390/molecules26165100
Transparency: funded by Fondazione CRT; according to the publication, no conflicts of interest. No product-related statement for DON DONKEY’S®.
Summarised and reviewed by the DON DONKEY’S editorial team on the basis of the original publication · as of October 2026
The study summarised above was carried out independently of DON DONKEY’S® and does not relate to our products. It serves solely to inform about the state of research.
DON DONKEY’S® donkey milk and donkey milk powder are foods. They are not intended to prevent, treat or cure any disease and do not replace medical advice.
From our shop
DON DONKEY’S® donkey milk
100 % donkey milk · raw milk, frozen
On this page we report the findings of a published study. Independently of that, you will find our donkey milk here: 100 % donkey milk, frozen as raw milk.
100 ml bottle / 100ml · Unit price: €249,00 / 1 l · incl. VAT, plus shipping
Also in our shop
Donkey Milk Powder
Donkey milk in powder form
For anyone who prefers a longer shelf life: our donkey milk in powder form – easy to store and portion.
20g · Unit price: €1.245,00 / 1 kg · incl. VAT, plus shipping