Premium
Sulfur Amino Acid Stability. Hydrogen Peroxide Treatment of Casein, Egg White, and Soy Isolate
Author(s) -
CHANG K. C.,
MARSHALL H. F.,
SATTERLEE L. D.
Publication year - 1982
Publication title -
journal of food science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.772
H-Index - 150
eISSN - 1750-3841
pISSN - 0022-1147
DOI - 10.1111/j.1365-2621.1982.tb07644.x
Subject(s) - cysteic acid , methionine sulfoxide , methionine , chemistry , casein , sulfone , hydrogen peroxide , sulfoxide , cystine , cysteine , sulfur , soy protein , amino acid , organic chemistry , biochemistry , enzyme
Egg white solids (EWS), soy protein isolate (SPI), and casein were treated with differing levels of H 2 O 2 at both 40 and 90°C. Total and reactive cysteine/cystine (Cys), total methionine, methionine sulfoxide and sulfone contents were determined for all samples. At 40°C methionine in all samples was readily converted to its sulfoxide, with little sulfone or cysteic acid being formed. At 90°C Cys was rapidly converted to the stable cysteic acid and methionine to its stable sulfone form. The production of the less stable methionine sulfoxide at 90°C was minimal. Of the three proteins studied, the methionine and Cys residues in EWS were least stable under oxidizing conditions, whereas those present in SPI and casein were more stable.