Albumin from chicken egg white grade 2

Soy protein isolate (SUPRO® 500E IP) (SPI) with a protein content of 83.4% (w/dw) was purchased from Solae (St. Louis, Missouri, USA). Pea protein concentrate (NUTRALYS® F85G) (PPC) was acquired from Roquette (France) with a protein content of 75% (w/dw). Whey protein isolate (WPI) (Bipro, lot no. JE 034–70–440-3) was supplied by Davisco Food International, Inc. (Le Sueur, USA) with a protein content of 99.3% (w/dw), while casein from bovine milk was supplied by FrieslandCampina (Wageningen, The Netherlands) with a protein content of 95.9% (w/dw). Albumin from chicken egg white (grade II) was purchased from Sigma-Aldrich (St. Louis, Missouri, USA) with a protein content of 92% (w/dw). The protein content of the sources was measured by Dumas analysis (Nitrogen analyser, FlashEA 1112 series, Thermo Scientific, Interscience, Breda, The Netherlands) in triplicate, using conversion factors of 5.71 for soy, 5.52 for pea, 6.25 for whey, 6.35 for casein and 6.45 for albumin from chicken egg white. Pepsin from porcine gastric mucosa (400–800 units/mg, P7125), mucin from the porcine stomach (Type III, M2378-100G) and all other chemicals were purchased from Sigma-Aldrich, Inc. (St. Louis, MO, U.S.A.). Milli-Q water (18.2 MΩ cm at 25 °C, Millipore Corporation, Molsheim, France) was used for all experiments.