title: Heat-induced changes in the susceptibility of egg white proteins to enzymatic hydrolysis: a kinetic study.
abstract: A kinetic study was conducted on the effect of heating in the temperature range of 50-92 degrees C, on the susceptibility of ovalbumin and albumen solutions to enzymatic hydrolysis by a mixture of trypsin and alpha-chymotrypsin at 37 degrees C and pH 8.0. Heat treatment resulted in an increase in degree of hydrolysis after 10 min of enzymatic reaction of both ovalbumin and albumen, as measured using the pH-stat method. The time-dependent change in the susceptibility to enzymatic hydrolysis after heat treatment was described by a fractional conversion model (based on an apparent first-order reaction kinetic model). Different end levels of degree of hydrolysis were obtained after heating for a long time at different temperatures, which suggests that the final degree of unfolding of the protein is temperature dependent.
authors.affiliation: Laboratory of Food Technology, Department of Food and Microbial Technology, Faculty of Agricultural and Applied Biological Sciences, Katholieke Universiteit Leuven, Kasteelpark Arenberg 22, B-3001 Heverlee, Belgium.
authors.forename: Iesel
authors.initials: I
authors.lastname: Van der Plancken
authors.forename: Marijke
authors.initials: M
authors.lastname: Van Remoortere
authors.forename: Indrawati
authors.initials: I
authors.lastname: Indrawati
authors.forename: Ann
authors.initials: A
authors.lastname: Van Loey
authors.forename: Marc E
authors.initials: ME
authors.lastname: Hendrickx
mesh_terms: D002918:Chymotrypsin / Q000378:metabolism*; D004527:Egg Proteins / Q000737:chemistry / Q000378:metabolism*; D006358:Hot Temperature; D006863:Hydrogen-Ion Concentration; D006868:Hydrolysis; D007700:Kinetics; D010047:Ovalbumin / Q000378:metabolism; D011489:Protein Denaturation; D013379:Substrate Specificity; D014357:Trypsin / Q000378:metabolism*
chemical_list: D004527:Egg Proteins; D010047:Ovalbumin; D002918:Chymotrypsin; C117608:alpha-chymotrypsin; D014357:Trypsin