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Research on donkey milk · Study 92
Fresh vs. freeze-dried donkey milk
Fresh donkey milk and donkey milk reconstituted from freeze-dried powder from 18 Ragusana jennies compared: protein 1.62 vs. 1.61 %, energy 38.2 vs. 39.0 kcal/100 ml – no significant differences.
At a glance · tap the cards
The key figures
Study design
How it was studied
In June 2016, milk from the morning milking of 18 multiparous Ragusana jennies (7–9 years, 90–110 days after foaling) on a registered farm in Capestrano (Abruzzo) was sampled in duplicate. One part was analysed fresh; the other was freeze-dried in a laboratory freeze dryer: 1 hour freezing at −45 °C, 48 hours primary drying at 0.10 mbar, 3 hours secondary drying at 5 °C. For the comparison, 0.9 g of powder was dissolved in 10 ml of distilled water (90 % moisture). Basic composition, energy value (bomb calorimeter), fatty acid profile (gas chromatography) and minerals were determined.
Interactive chart · values from the study
Composition: fresh vs. reconstituted donkey milk
Means from Table 2; according to the study, none of the differences were significant. Dry matter 9.56 vs. 9.69 %.
Second analysis
Minerals: fresh vs. freeze-dried donkey milk
Means from Table 4; according to the study, none of the differences were significant.
Results
What the study measured
The freeze-dried powder consisted of 96.9 % dry matter with 3.1 % residual moisture. The largest component was lactose (73.2 %), followed by protein (16.1 %), fat (4.48 %) and ash (3.20 %).
Between fresh and reconstituted milk, the authors found no significant differences in dry matter (9.56 vs. 9.69 %), lactose (7.08 vs. 7.23 %), protein (1.62 vs. 1.61 %), fat (0.44 vs. 0.48 %) and ash (0.42 vs. 0.37 %).
The energy value did not differ significantly either: 38.2 kcal/100 ml in fresh and 39.0 kcal/100 ml in reconstituted milk. The authors described the low energy content as a major limitation for feeding children in their first year of life without suitable supplementation.
The fatty acid profile showed no significant differences. The most common were oleic acid (26.8 vs. 28.3 %), palmitic acid (21.1 vs. 19.3 %) and linoleic acid (9.03 vs. 8.22 %); EPA was 0.29 and 0.28 %, DHA 0.31 and 0.30 % (fresh vs. freeze-dried in each case).
Among the minerals, calcium was highest (714.2 vs. 762.3 mg/kg), followed by phosphorus, potassium, chloride, sodium and magnesium (25.8 vs. 28.6 mg/kg). None of the differences were significant.
Authors’ conclusion: The authors concluded that the nutritional characteristics of freeze-dried donkey milk were very similar to those of fresh milk and that freeze-drying could be a useful process for offering donkey milk all year round, as the powder is easy to transport and can be stored without special conditions.
Critical assessment
Strengths and limitations
Broad range of analysesStrength
Composition, energy value, 17 fatty acids and six minerals were compared in fresh and freeze-dried milk of the same origin.
One farm, one time pointClear limitation
All samples came from 18 jennies on one farm in June 2016; the text speaks of pooled milk samples, yet the tables give n = 18.
Powder measured only directly after productionClear limitation
All analyses were carried out immediately after freeze-drying. How the powder behaves over a longer storage period was not examined.
Inconsistencies in tablesNote
Σ n-6 of the fresh milk (9.57 %) does not match the sum of the listed n-6 fatty acids (9.26 %); C20:0 (0.68 vs. 1.76 %) is marked as not significant despite small standard errors. The unit of the somatic cell count (“29.65 SCC/ml”) is probably incomplete.
Label in Table 3Note
Table 3 says “freeze-dried”; according to the methods, the reconstituted milk was measured.
Discussion goes beyond the dataNote
Statements in the discussion and conclusion about disease prevention are based on the literature and were not examined in this study.
Editorial assessment: A laboratory comparison of fresh and freeze-dried donkey milk from one farm; the study describes composition values of the milk and does not examine effects in humans. To the research archive.
Research question for DON DONKEY’S®
Do the composition and fatty acid profile of freeze-dried donkey milk powder remain stable over a longer storage period?
Original publication
Comparison of Nutritional Characteristics of Fresh and Freeze-Dried Donkey Milk
Original title of the publication.
Polidori P., Spera M.D., Sabatini A., Vincenzetti S.
Food Science and Nutrition Technology · 2019 · volume 4, issue 1, article 000172
School of Pharmacy, University of Camerino, Camerino (MC), Italy; School of Biosciences and Veterinary Medicine, University of Camerino, Matelica (MC), Italy
10.23880/fsnt-16000172: 10.23880/fsnt-16000172
Transparency: funding not stated. The authors declare 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
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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