?-Caseinophosphopeptide (f1-25) confers on ?-casein tryptic hydrolysate an antioxidant activity during iron/ascorbate-induced oxidation of liposomes

Abstract

-Protein ingredients such as hydrolysates of milk proteins may improve the nutritive value of functional foods. For instance, β-casein tryptic hydrolysate could simultaneously increase iron absorption and prevent lipid oxidation in foods containing high contents of polyunsaturated fatty acids (PUFA). The aim of this study was to determine the antioxidant activity of β-casein tryptic hydrolysate and of its β-caseinophosphopeptide (f1-25) on Fe(III)/ascorbate-induced oxidation of muscle phospholipids in a liposome system. Oxygen consumption, conjugated dienes (CD), thiobarbituric acid reactive substances (TBARS) and volatile compounds were measured during oxidation at 25 °C of the liposomes in the presence of either the β-casein tryptic hydrolysate (0.24-2.4 mg·mL -1 ) or of its phosphopeptide (0.1-0.31 mg·mL -1 ). Oxygen consumption was significantly enhanced in the presence of β-casein tryptic hydrolysate or of the phosphopeptide (f1-25) and staircase curves were observed for the highest concentrations, showing complex oxidative interactions between iron, β-casein tryptic hydrolysate or phosphopeptide and the phospholipids. In contrast, on an hourly scale, formation of CD, TBARS and total volatile compounds were inhibited. The inhibition of CD and TBARS reached 50% after 20 h of oxidation in the presence of 1.2 mg·mL -1 β-casein tryptic hydrolysate or 0.16 mg·mL -1 phosphopeptide (f1-25). Amounts of total volatile compounds produced after 24 h decreased by about 60% in the presence of the hydrolysate (1.2 mg·mL -1 ) and 50% with the phosphopeptide (f1-25) (0.31 mg·mL -1 ) due to drastic decrease or even disappearance of alkanals and 2-alkenals. Several alcohols such as pentanol and hexanol were produced in higher amounts. Thus β-casein tryptic hydrolysate can protect rich-in-PUFA phospholipid liposomes against long-term iron-induced oxidation, mainly due to iron chelation by β-caseinophosphopeptide (f1-25). This antioxidant activity could benefit specific food products.

Caseinophosphopeptide-Bound Iron: Protective Effect against Gut Peroxidation

“…In the presence of Fe-␤ -CPP(1-25), MDA levels were as low as in the iron-deprived group. MDA levels were higher in cells grown with FeSO 4 and highest in cells grown with Fe-P (p ! 0.001).…”

“…Previous in vitro studies assessed the protective effect of cow's milk proteins and cow's milk-derived peptides on peroxidation [3,4] .…”

“…Both whole caseins and caseinophosphopeptides (CPP), such as ␤ -casein-derived ␤ -CPP(1-25), were previously shown in vitro to have protective properties against peroxidation [3,4] . In addition, experimental [5] and human [6] studies have previously show that ␤ -CPP(1-25) enhances iron absorption.…”

Antioxidant effect of casein phosphopeptides compared with fruit beverages supplemented with skimmed milk against H2O2-induced oxidative stress in Caco-2 cells

“…However, it also has been suggested that CPPs could inhibit lipid oxidation by chelation with non-phosphorylated groups such as Glu and Asp, and/or via non-chelating mechanisms such as free radical scavenging (Kitts, 2005). Previous authors have shown that CPPs exhibit both primary and secondary antioxidant activities in aqueous (Chin & Kitts, 2004) and lipid emulsion systems (Diaz, Dunn, McClements, & Decker, 2003), in phosphatidylcholine liposome model systems (Kansci, Genot, Meynier, Gaucheron, & Chobert, 2004), and in beef homogenates (Diaz & Decker, 2004;Sakanaka, Tachibana, Ishihara, & Juneja, 2005). In contrast, the ability of CPPs to prevent the latter effects caused by oxidative stress in any biological system remains poorly understood and inconclusive.…”

Native, but not thermally denatured lactoferrin solubilizes iron in the presence of bicarbonate ions

“…β-Caseinophosphopeptide (β-CN 1-25 ) can also facilitate iron absorption and has antioxidant activity similar to that o fF e L f .I nc o n t r a s tt oF e L f ,t h es t r u c t u r e -function relationship of β-CN 1-25 is well characterized (Kansci et al 2004). The objective of this study was to extend our understanding of iron solubilization by Lf in the presence of bicarbonate anions to develop a manufacturing process and appropriate applications for FeLf.…”