Identification and quantification of inhibitors for Angiotensin-converting enzyme in hypoallergenic infant milk formulas.
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.
Martin
Melanie
M
Institute of Food Chemistry, Technische Universität Dresden, Bergstrasse 66, D-01062 Dresden, Germany. thomas.henle@chemie.tu-dresden.de
Wellner
Anne
A
Ossowski
Ines
I
Henle
Thomas
T
D000485:Allergens / Q000032:analysis; D000806:Angiotensin-Converting Enzyme Inhibitors / Q000032:analysis*; D004151:Dipeptides / Q000032:analysis / Q000494:pharmacology; D006801:Humans; D006868:Hydrolysis; D007223:Infant; D041943:Infant Formula / Q000737:chemistry*; D007231:Infant, Newborn; D016269:Milk Hypersensitivity / Q000517:prevention & control*; D008894:Milk Proteins / Q000032:analysis / Q000276:immunology*; D008895:Milk, Human / Q000737:chemistry
D000485:Allergens; D000806:Angiotensin-Converting Enzyme Inhibitors; D004151:Dipeptides; D008894:Milk Proteins