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Updated: Jul 4, 2026
Peptide and Protein Quantification Using Automated Immuno-MALDI (iMALDI)
Published on: August 18, 2017
Identification and quantification of inhibitors for Angiotensin-converting enzyme in hypoallergenic infant milk
Melanie Martin1, Anne Wellner, Ines Ossowski
1Institute of Food Chemistry, Technische Universität Dresden, Bergstrasse 66, D-01062 Dresden, Germany. thomas.henle@chemie.tu-dresden.de
Abstract:
The potential of hypoallergenic (HA) infant milk formulas containing hydrolyzed milk proteins as main constituents to inhibit angiotensin-converting enzyme (ACE) in vitro was investigated. Seven commercially available HA products designed for babies up to 4 months showed a potent inhibition of ACE in vitro, with IC 50 values ranging between 3.2 and 68.5 mg of nitrogen/L. For six samples of conventional milk-based infant formulas and three breast milk samples, no inhibition was observed. Inhibitory potential did not correlate with the degree of hydrolysis. Using reversed-phase high-pressure liquid chromatography (RP-HPLC) coupled to electrospray ionization-time of flight-mass spectrometry (ESI-TOF-MS), 15 peptides known to inhibit ACE were identified. Among them, the highly potent ACE inhibitor Ile-Trp (IC 50 = 0.7 microM) was detected and quantified for the first time in the HA samples, representing the most effective ACE-inhibiting peptide that has ever been detected in food items. The overall inhibitory potential of the HA infant milk formulas could partly be explained by Ile-Trp.
