0000000000400622
AUTHOR
Esther Miquel
Stability of tocopherols in adapted milk-based infant formulas during storage
Abstract An evaluation is made of the effects of added α -tocopherol ( α -T) or α -tocopherol acetate ( α -TAc) combined with iron lactate or sulfate, storage time (up to 17 months) and storage temperature (22°C and 37°C) on the α -TAc, α -T, γ -tocopherol ( γ -T) and δ -tocopherol ( δ -T) content of infant formulas. Tocopherols were measured by normal phase HPLC and fluorescence detection after direct extraction, which allows the determination of both α -TAc and α -T. The α -TAc content was not affected by temperature or storage time, although the α -, γ - and δ -T contents, which were lower at 37°C than at 22°C, were significantly affected. The type of iron salt added (lactate or sulfate)…
Identification of Casein Phosphopeptides in β-casein and Commercial Hydrolysed Casein by Mass Spectrometry
Casein phosphopeptides (CPPs) in commercial hydrolysed casein (CE90CPP) and in β-CN (β-CN) after simulated gastrointestinal digestion (gastric stage pepsin, pH =2, 37°C 2h) and intestinal stage (pancreatic-bile extract, pH =5.2, 37°C 2h) were sequenced by on-line reversed-phase high performance liquid chromatography coupled to electrospray ionisation tandem mass spectrometry (RP-HPLC-ESIMS/MS). In β-CN digest five peptides that contained four to five phosphate groups and the cluster sequence SpSpSpEE (residues 17-21) were identified. All CPPs with one exception β-CN(1-24)4P, had the protein fragment β-CN(1-25)4P, which is one of the main CPPs produced in vivo digestion of casein and the re…
Identification of Novel Phosphopeptides After Simulated Digestion of αs2-casein by Tandem Mass Spectrometry
Casein phosphopeptides (CPPs) are encrypted in αs1-, αs2-and β-casein (CN) and can be released by in vitro, in vivohydrolysis or food processing of dairy foods. Bovine αs2-CN contains two cluster sequences of anionic phosphoseryl and glutamyl residues SpSpSpEE in its structure (residues 8–12 and 56–63), which can modulate mineral bioavailability. In this study αs2-casein (αs2-CN) was subjected to simulated gastrointestinal digestion. CPPs released were sequenced by on-line reversed-phase high performance liquid chromatography coupled to electrospray ionisation tandem mass spectrometry (RP-HPLC-ESIMS/MS). Six novel αs2-CN derived CPPs, Three of them (αs2-CN(54–87)4P,αs2-CN(24–70)4P and αs2-…
Effects and future trends of casein phosphopeptides on zinc bioavailability
This review focuses on studies of the effects of CPPs on zinc bioavailability. It evaluates the main differences in studies performed in the last two decades, such as methodology used to measure zinc, food matrix, CPP preparation, CPP dose, CPP:Zn molar ratio and presence and concentration of zinc absorption inhibitors, such as phytate, iron and calcium. The future trends of CPPs as functional ingredients in zinc-enriched or zinc-containing foods are also discussed.
Casein phosphopeptides released by simulated gastrointestinal digestion of infant formulas and their potential role in mineral binding
Abstract Adapted and follow-up milk-based infant formulas were subjected to gastrointestinal digestion simulating physiological conditions. The naturally occurring casein phosphopeptides (CPPs) generated were fractionated by anion exchange high-performance liquid chromatography and sequenced by tandem mass spectrometry. In both infant formula digests, a total of 19 CCPs from bovine casein were identified, of which 7 corresponded to α s1 -casein and 12 to α s2 -casein. Most CPPs had the cluster sequence SpSpSpEE, representing the binding sites for minerals. The distribution of calcium, iron and zinc content in CPP fractions eluted from the anion exchange column was also studied. The results …