ISSN:
1750-3841
Source:
Blackwell Publishing Journal Backfiles 1879-2005
Topics:
Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
,
Process Engineering, Biotechnology, Nutrition Technology
Notes:
SUMMARY: The brownish discoloration of coagulated albumen in hard cooked egg rolls by ultraviolet (UV) radiation involves the splitting and conformation changes of the peptide chain as suggested by an increase in the amount of nonprotein nitrogen and aromatic amino acids. The presence of water was essential in the development of discoloration, indicating that hydroperoxides and/or peroxides produced from water by the action of UV radiation could cause oxidation of tryptophan. The oxidative type of reaction was confirmed by the development of a similar brown color when coagulated albumen was heated in the presence of oxidizing agents. The discoloration could be prevented by reducing agents, however, once the color has been developed the agents become ineffective. Therefore, a two step mechanism was suggested for the UV discoloration of coagulated albumen: first, the peptide chain is hydrolyzed resulting in an increase in the amount of tryptophan available; second, the tryptophan molecule is oxidized producing a brown color.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1111/j.1365-2621.1969.tb12795.x
