In vitro digestibility of b-casein and b-lactoglobulin under simulated human gastric and duodenal conditions

G. Mandalari, K. Adel-Patient, V. Barkholt, C. Baro, L. Bennett, M. Bublin, S. Gaier, G. Graser, G.S. Ladics, D. Mierzejewska, E. Vassilopoulou, Y.M. Vissers, L. Zuidmeer, N.M. Rigby, L.J. Salt, M. Defernez, F. Mulholland, A.R. Mackie, M.S.J. Wickham, E.N.C. Mills

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127 Citations (Scopus)


Initially the resistance to digestion of two cow's milk allergens, beta-casein, and beta-lactoglobulin (beta-Lg), was compared using a "high-protease assay" and a "low-protease assay" in a single laboratory. The low-protease assay represents an alternative standardised protocol mimicking conditions found in the gastrointestinal tract. For the high-protease assay, both proteins were incubated with either pepsin or pancreatin and digestion monitored by sodium dodecyl sulphate-polyacrylamide gel electrophoresis and reverse phase-high performance liquid chromatography. The low-protease assay involved gastroduodenal digestion in the presence or absence of phosphatidylcholine (PC). Both beta-casein and beta-Lg were susceptible to hydrolysis by pepsin and pancreatin in the high-protease assay. In contrast, the kinetics of beta-casein digestion in the low-protease assay were slower, beta-Lg being pepsin resistant. During duodenal digestion, beta-Lg was gradually degraded and addition of PC slowed digestion. Subsequently, the reproducibility of the low-protease assay was assessed in 12 independent laboratories by visual assessment of the gels and densitometric analysis: the inter- and intra-laboratory variability was affected by sampling and electrophoresis method employed. The low-protease assay was shown to be reproducible. Future studies will extend these findings using a broader panel of proteins
Original languageEnglish
Pages (from-to)372-381
JournalRegulatory Toxicology and Pharmacology
Issue number3
Publication statusPublished - 2009


  • human pancreatic-juice
  • food allergens
  • gastrointestinal proteolysis
  • protein digestibility
  • pepsin digestion
  • stability
  • fluid
  • hydrolysis
  • resistance
  • ph


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