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Caseinophosphopeptide enrichment and identification
Author(s) -
Zhu YiShen,
FitzGerald Richard J.
Publication year - 2012
Publication title -
international journal of food science and technology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.831
H-Index - 96
eISSN - 1365-2621
pISSN - 0950-5423
DOI - 10.1111/j.1365-2621.2012.03094.x
Subject(s) - chemistry , chromatography , mass spectrometry , hydrolysis , tandem mass spectrometry , electrospray , hydrolysate , ethanol precipitation , electrospray ionization , extraction (chemistry) , biochemistry
Summary Caseinophosphopeptides (CPPs) were generated via tryptic hydrolysis of sodium caseinate followed by heat treatment (75 °C) at pH 6.0, 7.0 and 8.0. Calcium aggregation, ethanol precipitation and gallium immobilised metal affinity chromatography (IMAC) were applied to enrich the CPPs. Nano‐liquid chromatography electrospray ionisation‐quadrupole time‐of‐flight tandem mass spectrometry was used for phosphopeptide separation and identification. The combination of gallium IMAC isolation with calcium and ethanol precipitation appears to be a useful tool in characterising the fate of CPPs in CN hydrolysates during thermal processing. CPPs appeared to be less susceptible to thermal modification when heat‐treated at pH 7.0 than at pH 6.0 and 8.0. Different extents of methionine oxidation occurred in the CPPs depending on heat‐treatment pH. The results herein may have important implications for the manufacture of CPPs and for the quality control of CPP products.