Research on donkey milk · Study 78

Protein digested in the test tube: what the fragments showed in laboratory tests

A Turkish laboratory study subjected casein and whey from donkey and camel milk to simulated digestion. The resulting protein fragments (peptides) were then put through five chemical tests.

Important: A purely laboratory study (in vitro) with enzyme and radical tests in the test tube. No statement about any effect of donkey milk in humans.
0per cent degree of hydrolysis of the digested donkey whey (laboratory value)
Year · country2021 (online 2020) · Turkey
MaterialDonkey and camel milk, casein and whey each
DesignLaboratory experiment, static simulated digestion
Replicates2 experimental runs × 3 measurements

What it's about

Four samples, five laboratory tests

Milk protein consists roughly of two groups: casein and whey proteins. During digestion, enzymes break both down into short chains. The study asked how such fragments from donkey and camel milk behave in chemical laboratory tests. Abbreviations on this page: DC = digested donkey casein, DW = digested donkey whey, CC and CW = the same for camel milk.

PeptidesShort chains of amino acids formed when protein is broken down.
Degree of hydrolysisShare of cleaved bonds in the protein – a measure of how far digestion has progressed in the glass.
Radical testsDPPH, ABTS and CUPRAC measure chemically how strongly a sample scavenges or reduces test molecules.
IC50The concentration at which a test is inhibited by half. Smaller value = stronger effect in the test tube.

Trial procedure · runs automatically

From milk to the measuring plate

Origin of the milk according to the paper: one donkey milk farm and one camel milk farm each in Turkey. The number of animals, breeds and number of milk samples are not stated.

Measurements after digestion

How much was broken down?

Each lamp is a mean from Table 1 of the paper. Whey was cleaved more than casein – yet the most peptides were measured from donkey casein.

Peptide concentrationmg/mL · mean ± standard deviation
Degree of hydrolysis% cleaved bonds · mean ± standard deviation
Donkey milkCamel milkhollow = whey · filled = casein

According to the paper, DC (highest peptide concentration) and CC (lowest) differed significantly from the other samples (P < 0.05); for degree of hydrolysis, both whey samples were significantly above both casein samples.

Key findings · tap the wells

The results plate: 20 wells, 5 tests

named in the text as the strongest samplemedium / higher than wheylowercontradictoryno result in the text

Colour intensity = ranking according to the paper’s text, schematic. Numbers appear only where the paper explicitly states them; many individual values appear only in figures or are marked as “data not shown”. DPP-IV and α-glucosidase are enzymes – what was measured was their inhibition in the test tube, not an effect in the body.

Critical assessment

Seven test strips for this study

Unknown samples

Neither the number of animals nor breeds nor the number of milk samples are stated. For each type of milk, the milk comes from one farm.

clear

Contradictions

α-glucosidase for CW/DW: “not determined”, then 32.84 and 89.38 %. Best DPP-IV value: DC in the results section, CC in the conclusion.

clear

Hidden data

Several key values only in figures or “data not shown”. Concentrations of the samples in the tests are missing.

medium

Digestion briefly described

Only a reference to a standard protocol; pH values, times and enzyme amounts are not in the text.

medium

Peptides not identified

Which peptides were formed was not determined – only total amount and HPLC profile.

medium

Test tube only

Chemical tests and isolated enzymes say nothing about what happens in the body. The author herself calls for further studies.

limit of the design

Transparency

Recognised digestion protocol, five different test methods. No funding, no conflicts of interest declared.

good
Level of evidenceBasic research in the test tube (in vitro): chemical and enzymatic laboratory tests without cells, animals or humans. Describes properties of peptide mixtures, not effects.
Funding & interestsAccording to the paper, no funding from public, commercial or non-profit funders. The author declares no conflicts of interest. Single-author work.

Editorial assessment: The author sees the peptides as possible candidates in connection with type 2 diabetes. This was not examined and cannot be derived from enzyme tests in the test tube – we expressly do not adopt this interpretation.

Research question for DON DONKEY’S®

Which peptides are formed from donkey casein – and how robust is the result?

The study measures totals but does not identify individual peptides. We are interested in whether other research groups, with openly described conditions and more milk samples, arrive at similar rankings – and whether freezing or freeze-drying changes the peptide pattern.

Compare with Study 1 (simulated digestion)Compare with Studies 52 and 53 (fermented donkey milk)Look for independent replication

Original publication

An evaluation of the in vitro antioxidant and antidiabetic potentials of camel and donkey milk peptides released from casein and whey proteins

Original title; “antidiabetic” is the author’s choice of words for enzyme tests in the test tube.

Akan E.
Journal of Food Science and Technology · 2021 · volume 58, issue 10, pp. 3743–3751 · online since 12 October 2020 · freely available via PubMed Central (PMC8357899)
Turkey

DOI: 10.1007/s13197-020-04832-5

Transparency: according to the paper, no funding; no conflicts of interest declared. A correction to the article was published (2021). 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

End of the study summary
Note on our products

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.

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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.

Transparency: The study examined milk from a donkey dairy farm in Turkey – not the milk of our partner farms.
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Donkey Milk Powder

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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.

Transparency: The study examined fresh donkey milk, not our donkey milk powder.
€24,90

20g · Unit price: €1.245,00 / 1 kg · incl. VAT, plus shipping

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