Preparation of ingredients containing an ACE-inhibitory peptide by tryptic hydrolysis of whey protein concentrates

Abstract

This study describes the characterisation of whey protein hydrolysates obtained from tryptic hydrolysis to assess their application as ingredients with angiotensin-converting-enzyme (ACE) inhibitory action. The levels of a-lactalbumin (a-la) and b-lactoglobulin (b-lg) remaining after hydrolysis were quantified. Peptides were separated by RP-HPLC, and Ala-Leu-Pro-Met-His-Ile-Arg (ALPMHIR), the most potent b-lg-derived ACE-inhibitory peptide was monitored. A correlation curve was established for the production of this peptide as a function of hydrolysis time. Heat-induced gelation of hydrolysates was studied by small-deformation rheology. The gelation times and the strength of the final gels were highly dependent on the degree of hydrolysis. Smaller peptides liberated by hydrolysis contributed to the inability of whey protein hydrolysates to gel. r

Milk-derived bioactive peptides: From science to applications

“…Blood pressure reducing peptides which inhibit the angiotensin converting enzyme I (ACE) are most studied (Li et al, 2004;Meisel et al, 2006;Murray & FitzGerald, 2007;Saito, 2008). Casein hydrolysates have in some studies produced higher ACE-inhibitory activity than whey protein hydrolysates but also whey peptides such as Ala-Leu-ProMet-His-Ile-Arg (ALPMHIR) from tryptic digest of b-lg have been identified with strong antihypertensive activity (Mullally et al, 1997;Maes et al, 2004;Ferreira et al, 2007). Also other proteolytic enzymes, such as Alcalase, Thermolysin, Subtilisin and successive treatment with pepsin and trypsin in order to simulate gastrointestinal digestion have been employed to release various bioactive peptides, including CCPs (McDonagh & FitzGerald, 1998), ACE inhibitory (Pihlanto-Leppä lä et al, 2000;Vermeirssen et al, 2004;Roufik et al, 2006;deCosta et al, 2007), antibacterial (Ló pez-Expó sito & Recio, 2006;Ló pez-Expó sito et al, 2007), antioxidative (Pihlanto, 2006) immunomodulatory and opioid-like (Teschemacher, 2003).…”

Physico-chemical characterization of chitosan-based edible films incorporating bioactive compounds of different molecular weight

“…The peptide fraction was obtained from hydrolysis of WPC (80% wt of protein, Arla Foods, Denmark) performed based on the methodology described by Ferreira et al (2007). The generated hydrolysates were subjected to a dialysis using tubular dialysis membrane having defined molecular weight cut-off value of 1.0 kDa (Cellu-Sep H1, Membrane filtration products, USA).…”

Effects of lactokinins from fermented acid goat whey on lipid content and adipogenesis of immortalised human adipocytes

“…Whey possesses important nutritional and biological properties, particularly against hypertension through ACE inhibitors crypted in proteins (Ferreira et al, 2007). Lactokinins may contribute to the anti-obesity effects of milk and whey as evoked by Zemel (2005).…”