Buyer protection
Donkey milk research · Study 182
Fresh, frozen or powdered: donkey milk protein fractions compared
A research group at the University of Camerino compared fresh donkey milk, milk frozen at −20 °C and spray-dried milk. According to the authors, the 3 variants showed different values for total protein, casein, whey protein and lysozyme. How large the differences were and in which direction they went is not stated in the abstract.
At a glance · swipe or use the arrows
The key figures
Study design
How it was studied
Comparative milk analysis with a patent review by two authors from the University of Camerino (Matelica site, Italy). Because donkey milk is available seasonally, they studied the effects of spray-drying and storage at −20 °C on its protein fractions. Fresh, frozen and powdered donkey milk were compared for total protein, casein, whey protein and lysozyme. Evaluated based on the abstract: it does not give sample numbers, the origin of the milk, duration of frozen storage, drying conditions, methods or figures.
Results
What the study measured
According to the authors, fresh donkey milk, milk frozen at −20 °C and spray-dried milk showed different values for total protein.
The three variants also differed in casein, whey protein and lysozyme.
The abstract does not state how large the differences were or whether freezing or drying raised or lowered the values.
The authors cite the seasonal availability of donkey milk, which makes storage and preservation necessary, as the reason for the study.
The paper also presents patents dealing with protein fractions in fresh, frozen and powdered donkey milk.
Authors’ conclusion: According to the authors, processing and storage changed the protein fractions of donkey milk; they point to promising patents. In the introduction, they describe donkey milk as similar to human milk in composition and digestibility. These statements on infant feeding come from the literature cited and were not studied here. Donkey milk is not a substitute for breast milk or infant formula; infant feeding belongs in medical hands.
Critical appraisal
Strengths and limitations
No figures in the abstractClear limitation
Neither values nor the direction of the differences are given. Whether freezing or drying raised or lowered individual fractions remains open.
Statements on infant feedingClear limitation
The introduction presents donkey milk as a breast milk substitute. This was not part of the measurements and is not adopted here.
Only the abstract assessedNote
Sample numbers, storage time, drying conditions and methods were not available.
Patent-oriented journalNote
The paper appeared in a journal for patent reviews. Part of the content is a presentation of patents, not the authors’ own measurements.
Practical comparisonStrength
The study sets side by side exactly the three forms in which donkey milk is traded: fresh, frozen and as powder.
Editorial note: The question of how freezing and drying change donkey milk is highly relevant. However, the abstract only shows that there were differences, not how large they were or in which direction they went. No statements about our products can be derived from it. To the research archive.
Research question for DON DONKEY’S®
How do total protein, casein, whey protein and lysozyme differ between a batch before freezing, after thawing and after drying to powder?
Original publication
Differences of protein fractions among fresh, frozen and powdered donkey milk.
Original title: Differences of protein fractions among fresh, frozen and powdered donkey milk.
Polidori P., Vincenzetti S.
Recent Patents on Food, Nutrition & Agriculture · 2010 · 2(1), 56–60
Department of Environmental Sciences, University of Camerino, Matelica, Italy (according to the paper)
DOI: 10.2174/2212798411002010056
Transparency: non-governmental research support according to the database record (no details); conflicts of interest could not be checked from the abstract. No product-related statement for DON DONKEY’S®.
Summarised and checked by the DON DONKEY’S editorial team against the original publication · As of: November 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