High angiotensin I‐converting enzyme inhibitory activity, bioaccessibility and bioavailability of milk protein hydrolysate by commercial proteases formulated with Pseudomonas aeruginosa protease

Abstract

Milk protein hydrolysate was optimally prepared by Protamex and PaproA (MP‐PP) exhibiting excellent angiotensin I‐converting enzyme (ACE) inhibitory activity (89.6%) at 0.5 mg/mL and protein recovery rate (79.0%). Meanwhile, MP‐PP was stable for acid–base and heat treatments, and even presented 80.5% of ACE inhibitory activity after handling in gastrointestinal fluids. However, transepithelial transportation via Caco‐2 cell monolayer lowered ACE inhibition of MP‐PP. Following the fractionation of MP‐PP, IESPPEI was identified as an outstanding ACE inhibitory peptide (IC50 of 6.4 μM), comparable with commercial VPP and IPP. Overall, MP‐PP and IESPPEI are potential functional ingredients to develop antihypertensive products.