Dairy Debaryomyces hansenii strains produce the antihypertensive casein-derived peptides LHLPLP and HLPLP

- Dairy Debaryomyces hansenii strains release casein-derived antihypertensive peptides.
- Peptides LHLPLP and HLPLP were identified in D. hansenii Dh1 and Dh14 hydrolysates.
- LHLPLP and HLPLP represented up to 10% of total peptide content in hydrolysates.
- D. hansenii hydrolysates might exert different functional effects.

The ability of dairy Debaryomyces hansenii, Kluyveromyces lactis and Kluyveromyces marxianus strains to release the casein-derived antihypertensive sequences RYLGY, AYFYPEL, LHLPLP, HLPLP, VPP and/or IPP was examined. Yeast strains were grown in medium with casein as sole nitrogen source and the yeast casein hydrolysates (CSHs) were analysed by HPLC-MS/MS to search for the six antihypertensive sequences. Only LHLPLP and HLPLP were identified in CSHs and exclusively in D. hansenii Dh1 and Dh14 hydrolysates in which both antihypertensive sequences represented approximately 6 (CSH Dh1) and 10% (CSH Dh14) of total peptide content. In addition, a complete analysis of selected CSHs by HPLC-MS/MS allowed the identification of 35 (Dh1) and 46 (Dh14) additional peptides, which could also contribute to the observed in vitro ACE inhibitory potency of both hydrolysates (Dh1, IC50 = 13.6 ± 1.8 μg/mL; Dh14, IC50 = 17.5 ± 2.1 μg/mL) and might confer them multifunctional properties. Finally casein zymography revealed the presence of at least one extracellular protease with a molecular mass of about 50 kDa. In conclusion, the present study contributes to a better insight into bioactive compounds produced by dairy yeasts and shows the feasibility of D. hansenii strains to produce antihypertensive casein-derived peptides.