Dipeptidyl peptidase IV (DPP-IV) inhibitory properties of camel milk protein hydrolysates generated with trypsin

- Sixteen camel milk protein hydrolysates (CMPHs) were produced with trypsin.
- CMPHs display dipeptidyl peptidase IV (DPP-IV) inhibitory properties in vitro.
- CMPHs showed higher DPP-IV inhibition than bovine milk protein hydrolysates (BMPHs).
- Major differences in DPP-IV inhibitory peptides within CMPHs and BMPHs were shown.
- Camel milk proteins are potentially interesting antidiabetic agents.

Dipeptidyl peptidase IV (DPP-IV) inhibitory peptides were identified in silico within camel milk proteins. Camel milk was hydrolysed with trypsin using a design of experiments (DOE, temperature (40-60 °C), enzyme to substrate (E:S) ratio (0.50-2.00% (w/w)) and time (60-240 min)). Fifteen hydrolysates (H1-H15) having DPP-IV half maximal inhibitory concentration (IC50) values between 0.52 ± 0.06 (H9) and 1.26 ± 0.13 (H1) mg mL−1 were produced. Camel and bovine milk proteins hydrolysed at 40 °C, 1.8% E:S and 218 min had DPP-IV IC50 values of 0.68 ± 0.08 and 0.85 ± 0.10 mg mL−1 (p < 0.05), respectively. Potent and unique DPP-IV inhibitory peptides (Leu-Pro-Val-Pro-Gln and Trp-Lys) were identified in camel milk protein hydrolysates, which were not present in bovine milk protein hydrolysates. The DPP-IV inhibitory properties of camel milk peptides were reported for the first time in this study. Camel milk is an interesting substrate to further investigate for its antidiabetic potential.

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